# Bitcoin glossary | Coinbase Help

• Bitcoin glossary | Coinbase Help
• Bitcoin Is More Stable Than You Think - Blockchain
• The days of bitcoin doubling in a week are over — fintech
• Multiply BTC Times - Multiply Your Bitcoins in Hours
• Bitcoin Daily Transaction Value Is Set to Fall Below Tether’s
##### Aeon

Aeon (AEON) is a private, secure, untraceable currency. You are your bank, you control your funds, and nobody can trace your transfers.

##### Improvements to Nano Homepage

Hi all
I think we can make the Nano homepage more informative for new users.
In its current state, users new to Nano who visit our homepage are likely to not understand the value proposition of Nano.
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a. We talk about how "Nano makes money efficient for a more equal world - simple to pay with, easy to accept and open to all", but then immediately point out how we're feeless, eco-friendly, and instant.
How do those 3 things prove/demonstrate the initial claim?
We can do a better job by starting off with the things that make us unique: feeless, eco-friendly, instant finality, decentralized, and secure (running since 2015, audited by Red4Sec).
> Then we should dive into why each of these things are different from all other cryptos out there. Give graphs for how we're decentralized, show live average transaction time, link to the audit, compare energy usage and fees to bitcoin, etc. These should all be on the front page for new users to be able to understand what makes us different.
> Otherwise, it's so easy to make the argument that other coins are already low fees and really fast too. So why should I care about Nano? We don't do a good job explaining this point.
> AND THEN we can put our vision statement for how we want to make the world more equal, etc. The page should read like an argument, not some random bullet points put together on a page.
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b. Users should not have to go down to the FAQ section to learn about Nano.
It's not an FAQ to want to learn what Nano is about - that's the reason I came to your website!
> When I hover over "Learn More", I get shown "Resources", "Developer Tools", "Blog" and "Nano Foundation". Why would I click any of those things without even knowing what this Nano thing is and what makes it special from the 1000+ other coins?
> We have wonderful docs about Nano is from a technical point of view. We need to simplify and present these things in a non-technical manner on our front page.
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c. We should try to be more visual when making an argument.
Take a look at how other coins are presenting their case on their websites: Hedera, Stellar, Zilliqa. Their arguments are relatively easy to follow. Ours are not. Let's change that.
Anyone agree? I'm open to feedback.

##### A Market Liquidity Theory of the Current Financial Crisis

Huge update from the Fed this morning: https://www.federalreserve.gov/newsevents/pressreleases/monetary20200323b.htm
I'm not going to have a chance to look through this in detail this morning, but it looks like the Fed might be engaging in a massive loan program and taking just about anything as collateral.
This is going to be a long post and analysis that I have written as much to get my thoughts in order as much to post on here for any feedback or criticism.
Essentially, like many on here, I do not believe that the current situation is a temporary down-turn, but a full blown financial crisis. We have already been hit with the initial shock of this crisis, so the question becomes: what comes next? Helping us understand what is fundamentally happening in the market will aid in making intelligent future predictions and investments. That leads to the question: what exactly is happening in the market right now? What caused us to suddenly drive off a cliff? And is there any way we can save it? Unlikely many here, I do not believe that COVID-19 is the actual underlying crisis. In my opinion, our economy was basically the end stages of a Jenga game, and COVID-19 is just the swift breeze knocking the whole thing over.
As I started looking for the next big market move, I started to wonder who was going to feel the most pain in these markets. Some reading led me to the thought that what we were seeing in the markets was a liquidity issue, and that companies with poor credit ratings will be most affected. I posted about this a couple of days ago, and several others came to the same conclusion as me. 1 2 3. There are other obliviously other problems in the market at the moment, but this analysis will focus on this problem in particular.
I now strongly believe that this hypothesis was correct, even if my initial reasoning and analysis was flawed. I outline a theory, followed by some supporting evidence, and finally some speculation. Finally, I don't think the Fed understands the actual problem the market is facing right now, nor does it have the tools to deal with it.
There are three prerequisites here: repos, collateral transformation, and rehypothecated collateral
Variation-Separate has already written an excellent technical analysis, and explains repos in part I. I will assume you have already read that section. 2
The basic idea behind collateral transforms is this: Your company needs some short-term liquid cash. In order for someone to give you this cash, you need collateral. You only have risky assets (such as junk bonds), but no one will accept them as collateral precisely because they are risky. Everyone in the market wants a secure asset (such as a Treasury). Instead of giving up, you go out and find someone who will loan you their Treasury and accept your junk bonds as collateral. You then use that Treasury to obtain the cash you need. This process can be repeated among many parties in order to create a "collateral chain".
Finally, we have rehypothecated collateral: Someone comes to you and wants to borrow an assets for a short period of time (such as a stock). They give you another asset (such as cash) as collateral in exchange for the stock. You know the borrower won't be back to collect this collateral for a while, so you invest that collateral to make money off of it in the meantime.
As Variation-Separate explains, there have been problems in the repo market recently, and the Fed has acted as the believe appropriate. However, this is not the first time the Fed has run into this problem . In fact, we had a problem a problem in the repo market just in Sept 2019 and "Not only did the spike in the repo rate come as a surprise to the New York Fed, but they also haven't been able to normalize it as quickly as they thought they could". Finally, let's consider that even though the fed has offered to pump massive amounts of liquidity into the market, banks aren't taking it and are quickly repaying that which they do take.
What exactly is going on then? The Fed tries to pump liquidity into the economy, and nothing happens. The reason for this is that the Fed knows that it doesn't understand the underlying problem in the market, and knows that is powerless to stop it. The Fed is trying to unleash every tool in its toolbox on the hope that if it just throws enough money into the market, eventually the problem will go away.
So what is the root problem? Essentially, liquidity. More specifically, collateral transformations and rehypothecated collateral. In fact, this has been written about extensively: 4 5, with Snider in particular making a strong case that today's crisis fits the analysis of the collateral markets that he provided in 2018: 6
How are collateral transformations and rehypothecated collateral affecting liquidity in the markets? There are numerous ways, but let's start with 2:
Let's say someone gives you cash as collateral, and you rehypothecate it as described in the example. However, instead of putting the cash in a safe asset, knowing you have to repay it, you put it in a very risky, high-yield asset such as a junk bond or MBS. Things go wrong, you lose your money and can't pay back your end of the repo. This is exactly what AIG did during the 2008 crisis. 7
Now let's say you engage in a long chain of collateral transformations. You start with a really risk assets, trade that for a sligtly less risky asset, trade that for a moderately risky asset, etc, until you eventually get a pristine asset. Now anyone along that chain can rehypothecate their collateral into some risky investment, causing a huge number of problems. Not to mention that if you, for some reason, can't fulfill your end of the repo, you screw a whole chain of people who have traded with you.
Now, if we are in a strong market, these problems won't arise too often. But what happens if, say, a virus comes out of now where causing wide-spread economic disruptions? Now, maybe those risky investments that would have paid out more often than not aren't pay out at all, causing systemic problems.
Now let's add a couple of things that exacerbate this problem even further:
These chains get so complicated that no one even knows who owns which assets anymore 4
When these chains collateral transformations start to fail, people may become less willing to take the risk of engaging in them 5
All of this caused heavy regulation on the exchange of collateral by primary lenders after the 2008 crisis. This has pushed these transactions into dark markets where we don't really understand what is going on. Here is my hypothesis, heavily taken from Snider's analysis:
Corporations have become heavily reliant on short-term lending for liquidity. However, most of them don't have pristine assets to exchange for cash, or DisneyBucks to float them through hard times. So what to do? You engage in collateral transformations: keep exchanging your junk assets until you get the pristine assets you need to get liquid cash. A bunch of corporations do this over and over again, and eventually they really don't have a clear of idea of what assets they really own.
Further, in these collateral chains they are rehypothecating collateral to make a quick buck. All is well, until this virus comes along. Suddenly, corporations are losing their collateral in these risky investments. Further, they need cash. The first thing they do is try to transform their collateral for short term liquidity. However, a bunch of people have just lost their money playing this game and don't want to play anymore, so it becomes more difficult and expensive for the companies to engage in these collateral transformations. The assets they have are worth less, so they have to sell other assets to compensate. However, everyone is doing this at the same time, devaluing the assets. Devaluation of assets makes it even more expensive to engage in collateral exchanges, and the cycle continues. Finally, when these companies take account of their actual assets, after all of these complicated exchanges, they realize they don't actually own what they think they own, creating additional panic when they are already in crisis mode. This causes huge turmoil, and the markets fall off a cliff.
If this theory is correct, what will we see next? Whether the markets will go up or down is dependent on too many factors to predict. However, I do have some speculation. First let's categorize corporations as follows:
Type I: Safe
Large banking institutions
Large P-1/A-1/F1+ Companies
Companies with huge cash reserves
Type II: Possibly Safe
Type III: Doomed
Business with >500 employees, no large cash reserves, not P-1/A-1/F1+
The self-employed
Type I businesses will certainly weather the storm. If they don't have the direct support of the Fed, they have large cash reserves on hand. If they don't have large cash reserves on hand, they have the credit rating to make use of corporate paper. They can find the short term funding needed to make it through this.
Type II businesses may be safe depending on the government response. I am currently underwhelmed by the "support" for small business in the stimulus bill, but there seems to at least be talk about this so maybe things will change. "Essential" businesses may receive a bailout to get them through tough times.
Type III businesses are completely screwed, no one seems to know they are even there. They won't qualify for support as "small businesses", and they have no way of obtaining liquid assets in this market. In particular, the larger businesses don't have the pristine assets to obtain liquidity in these markets, they are dependent on collateral transforms.
I won't predict whether the markets will go up or down this week, next, etc. But I will speculate this: I think the calm we saw in the markets was an actual calm. I think there was panic as businesses tried to obtain liquidity. They now believe they have the liquidity to make it through the near future, and are satisfied. There could be fire-sales in the near term for other reasons, but I don't think short-term liquidity will be the cause. However, most corporations don't speculate very hard when it comes to the future: they listen to the "experts". And these "experts" in government and the financials have been predicting doom and gloom for the next couple weeks, but that things will "bounce back" afterward. This is flatly false. As this becomes more apparent to these companies, I think we'll see another run on the market.
Particularly, it will be the large Type III business that will be the most vulnerable. They won't have any government stimulus support, and they won't have access to their normal modes of obtain cash. The last panic in the markets pushed bond yields so high that issuing new bonds will be completely out of the question. For them, it will be like a game of chess where your 4 moves away from being mated no matter what you do. Many of them will decide that bankruptcy is the best option in front of them.
Can the Fed prevent this? I don't think so. The Fed has the ability to soak up P-1/A-1/F1+, but they can only do this through the banks. But the banks aren't the ones in trouble this time, its the market itself. I have not read anything that leads me to believe that the Fed would be able to purchase junk assets from non- P-1/A-1/F1+ corporations without an act of Congress, and Congress is too slow and incompetent to see this problem coming or fix it in time. The Colosseum will be protected as Rome burns around it.
Sorry for any typos, poor wording. This was a long post.

##### /r/Scams Common Scam Master Post

Hello visitors and subscribers of scams! Here you will find a master list of common (and uncommon) scams that you may encounter online or in real life. Thank you to the many contributors who helped create this thread!

## If you know of a scam that is not covered here, write a comment and it will be added to the next edition.

Some of these articles are from small, local publications and refer to the scam happening in a specific area. Do not think that this means that the scam won't happen in your area.

# Spoofing

Caller ID spoofing
It is very easy for anyone to make a phone call while having any number show up on the caller ID of the person receiving the phone call. Receiving a phone call from a certain number does not mean that the person/company who owns that number has actually called you.
Email spoofing
The "from" field of an email can be set by the sender, meaning that you can receive scam emails that look like they are from legitimate addresses. It's important to never click links in emails unless absolutely necessary, for example a password reset link you requested or an account activation link for an account you created.
SMS spoofing
SMS messages can be spoofed, so be wary of messages that seem to be from your friends or other trusted people.

# The most common scams

The fake check scam (Credit to nimble2 for this part)
The fake check scam arises from many different situations (for instance, you applied for a job, or you are selling something on a place like Craigslist, or someone wants to purchase goods or services from your business, or you were offered a job as a mystery shopper, you were asked to wrap your car with an advertisement, or you received a check in the mail for no reason), but the bottom line is always something like this:
• The scammer sends you a very real looking, but fake, check. Sometimes they'll call it a "cashier's check", a "certified check", or a "verified check".
• You deposit the check into your bank account, and within a couple of days your bank makes some or all of the funds available to you. This makes you think that the check is real and the funds have cleared. However, the money appearing in your account is not the same as the check actually clearing. The bank must make the funds available to you before they have cleared the check because that is the law.
• For various and often complicated reasons, depending on the specific story line of the scam, the scammer will ask you to send someone some of the money, using services like MoneyGram, Western Union, and Walmart-2-Walmart. Sometimes the scammer will ask for you to purchase gift cards (iTunes, Amazon, Steam, etc) and give them the codes to redeem the gift cards. Some scammers may also give you instructions on how to buy and send them bitcoins.
• Within a couple of weeks, though it can take as long as a month, your bank will realize that the check you deposited was fake, and your bank will remove the funds that you deposited into your account and charge you a bounced check fee. If you withdrew any of the money from the fake check, that money will be gone and you will owe that money to the bank. Some posters have even had their bank accounts closed and have been blocked from having another account for 5 years using ChexSystems.
General fraudulent funds scams If somebody is asking you to accept and send out money as a favour or as part of a job, it is a fraudulent funds scam. It does not matter how they pay you, any payment on any service can be fraudulent and will be reversed when it is discovered to be fraudulent.
Phone verification code scams Someone will ask you to receive a verification text and then tell you to give them the code. Usually the code will come from Google Voice, or from Craigslist. In the Google version of the scam, your phone number will be used to verify a Google Voice account that the scammer will use to scam people with. In the Craigslist version of the scam, your phone number will be used to verify a Craigslist posting that the scammer will use to scam people. There is also an account takeover version of this scam that will involve the scammer sending a password reset token to your phone number and asking you for it.
Bitcoin job scams
Bitcoin job scams involve some sort of fraudulent funds transfer, usually a fake check although a fraudulent bank transfer can be used as well. The scammer will send you the fraudulent money and ask you to purchase bitcoins. This is a scam, and you will have zero recourse after you send the scammer bitcoins.
Email flooding
If you suddenly receive hundreds or thousands of spam emails, usually subscription confirmations, it's very likely that one of your online accounts has been taken over and is being used fraudulently. You should check any of your accounts that has a credit card linked to it, preferably from a computer other than the one you normally use. You should change all of your passwords to unique passwords and you should start using two factor authentication everywhere.
Boss/CEO scam A scammer will impersonate your boss or someone who works at your company and will ask you to run an errand for them, which will usually be purchasing gift cards and sending them the code. Once the scammer has the code, you have no recourse.
Employment certification scams
You will receive a job offer that is dependent on you completing a course or receiving a certification from a company the scammer tells you about. The scammer operates both websites and the job does not exist.
Craigslist fake payment scams
Scammers will ask you about your item that you have listed for sale on a site like Craigslist, and will ask to pay you via Paypal. They are scamming you, and the payment in most cases does not actually exist, the email you received was sent by the scammers. In cases where you have received a payment, the scammer can dispute the payment or the payment may be entirely fraudulent. The scammer will then either try to get you to send money to them using the fake funds that they did not send to you, or will ask you to ship the item, usually to a re-shipping facility or a parcel mule.
General fraudulent funds scams The fake check scam is not the only scam that involves accepting fraudulent/fake funds and purchasing items for scammers. If your job or opportunity involves accepting money and then using that money, it is almost certainly a frauduent funds scam. Even if the payment is through a bank transfer, Paypal, Venmo, Zelle, Interac e-Transfer, etc, it does not matter.
Credit card debt scam
Fraudsters will offer to pay off your bills, and will do so with fraudulent funds. Sometimes it will be your credit card bill, but it can be any bill that can be paid online. Once they pay it off, they will ask you to send them money or purchase items for them. The fraudulent transaction will be reversed in the future and you will never be able to keep the money. This scam happens on sites like Craigslist, Twitter, Instagram, and also some dating sites, including SeekingArrangement.
The parcel mule scam
A scammer will contact you with a job opportunity that involves accepting and reshipping packages. The packages are either stolen or fraudulently obtained items, and you will not be paid by the scammer. Here is a news article about a scam victim who fell for this scam and reshipped over 20 packages containing fraudulently acquired goods.
The Skype sex scam
You're on Facebook and you get a friend request from a cute girl you've never met. She wants to start sexting and trading nudes. She'll ask you to send pictures or videos or get on webcam where she can see you naked with your face in the picture. The scam: There's no girl. You've sent nudes to a guy pretending to be a girl. As soon as he has the pictures he'll demand money and threaten to send the pictures to your friends and family. Sometimes the scammer will upload the video to a porn site or Youtube to show that they are serious.
What to do if you are a victim of this scam: You cannot buy silence, you can only rent it. Paying the blackmailer will show them that the information they have is valuable and they will come after you for more money. Let your friends and family know that you were scammed and tell them to ignore friend requests or messages from people they don't know. Also, make sure your privacy settings are locked down and consider deactivating your account.
The underage girl scam
You're on a dating site or app and you get contacted by a cute girl. She wants to start sexting and trading nudes. Eventually she stops communicating and you get a call from a pissed off guy claiming to be the girl's father, or a police officer, or a private investigator, or something else along those lines. Turns out the girl you were sexting is underage, and her parents want some money for various reasons, such as to pay for a new phone, to pay for therapy, etc. There is, of course, no girl. You were communicating with a scammer.
What to do if you are a victim of this scam: Stop picking up the phone when the scammers call. Do not pay them, or they will be after you for more money.
Phishing
Phishing is when a scammer tries to trick you into giving information to them, such as your password or private financial information. Phishing messages will usually look very similar to official messages, and sometimes they are identical. If you are ever required to login to a different account in order to use a service, you should be incredibly cautious.
The blackmail email scam The exact wording of the emails varies, but there are generally four main parts. They claim to have placed software/malware on a porn/adult video site, they claim to have a video of you masturbating or watching porn, they threaten to release the video to your friends/family/loved ones/boss/dog, and they demand that you pay them in order for them to delete the video. Rest assured that this is a very common spam campaign and there is no truth behind the email or the threats. Here are some news articles about this scam.
The blackmail mail scam
This is very similar to the blackmail email scam, but you will receive a letter in the mail.
Rental scams Usually on local sites like Craigslist, scammers will steal photos from legitimate real estate listings and will list them for rent at or below market rate. They will generally be hesitant to tell you the address of the property for "safety reasons" and you will not be able to see the unit. They will then ask you to pay them a deposit and they claim they will ship you the keys. In reality, your money is gone and you will have no recourse.
Craigslist vehicle scams A scammer will list a vehicle on Craigslist and will offer to ship you the car. In many cases they will also falsely claim to sell you the car through eBay or Amazon. If you are looking for a car on Craigslist and the seller says anything about shipping the car, having an agent, gives you a long story about why they are selling the car, or the listing price is far too low, you are talking to a scammer and you should ignore and move on.
Advance-fee scam, also known as the 419 scam, or the Nigerian prince scam. You will receive a communication from someone who claims that you are entitled to a large sum of money, or you can help them obtain a large sum of money. However, they will need money from you before you receive the large sum.
Man in the middle scams
Man in the middle scams are very common and very hard to detect. The scammer will impersonate a company or person you are legitimately doing business with, and they will ask you to send the money to one of their own bank accounts or one controlled by a money mule. They have gained access to the legitimate persons email address, so there will be nothing suspicious about the email. To prevent this, make contact in a different way that lets you verify that the person you are talking to is the person you think you are talking to.
Cam girl voting/viewer scam
You will encounter a "cam girl" on a dating/messaging/social media/whatever site/app, and the scammer will ask you to go to their site and sign up with your credit card. They may offer a free show, or ask you to vote for them, or any number of other fake stories.
Amateur porn recruitment scam
You will encounter a "pornstar" on a dating/messaging/social media/whatever site/app, and the scammer will ask you to create an adult film with hehim, but first you need to do something. The story here is usually something to do with verifying your age, or you needing to take an STD test that involves sending money to a site operated by the scammer.
Hot girl SMS spam
You receive a text from a random number with a message along the lines of "Hey babe I'm here in town again if you wanted to meet up this time, are you around?" accompanied by a NSFW picture of a hot girl. It's spam, and they'll direct you to their scam website that requires a credit card.
Identity verification scam
You will encounter someone on a dating/messaging/social media/whatever site/app, and the scammer will ask that you verify your identity as they are worried about catfishing. The scammer operates the site, and you are not talking to whoever you think you are talking to.
This type of scam teases you with something, then tries to make you sign up for something else that costs money. The company involved is often innocent, but they turn a blind eye to the practice as it helps their bottom line, even if they have to occasionally issue refunds. A common variation takes place on dating sites/dating apps, where you will match with someone who claims to be a camgirl who wants you to sign up for a site and vote for her. Another variation takes place on local sites like Craigslist, where the scammers setup fake rental scams and demand that you go through a specific service for a credit check. Once you go through with it, the scammer will stop talking to you. Another variation also takes place on local sites like Craigslist, where scammers will contact you while you are selling a car and will ask you to purchase a Carfax-like report from a specific website.
Multi Level Marketing or Affiliate Marketing

## Phone scams

You should generally avoid answering or engaging with random phone calls. Picking up and engaging with a scam call tells the scammers that your phone number is active, and will usually lead to more calls.
Tax Call
You get a call from somebody claiming to be from your countries tax agency. They say you have unpaid taxes that need to be paid immediately, and you may be arrested or have other legal action taken against you if it is not paid. This scam has caused the American IRS, Canadian CRA, British HMRC, and Australian Tax Office to issue warnings. This scam happens in a wide variety of countries all over the world.
Warrant Call
Very similar to the tax call. You'll get a phone call from an "agent", "officer", "sheriff", or other law enforcement officer claiming that there is a warrant out for your arrest and you will be arrested very soon. They will then offer to settle everything for a fee, usually paid in giftcards.
[Legal Documents/Process Server Calls]
Very similar to the warrant call. You'll get a phone call from a scammer claiming that they are going to serve you legal documents, and they will threaten you with legal consequences if you refuse to comply. They may call themselves "investigators", and will sometimes give you a fake case number.
Student Loan Forgiveness Scam
Scammers will call you and tell you about a student loan forgiveness program, but they are interested in obtaining private information about you or demanding money in order to join the fake program.
Chinese government scam
This scam is aimed at Chinese people living in Europe and North America, and involves a voicemail from someone claiming to be associated with the Chinese government, usually through the Chinese consulate/embassy, who is threatening legal action or making general threats.
Chinese shipping scam
This scam is similar to the Chinese government scam, but involves a seized/suspicious package, and the scammers will connect the victim to other scammers posing as Chinese government investigators.
Social security suspension scam
You will receive a call from someone claiming to work for the government regarding suspicious activity, fraud, or serious crimes connected to your social security number. You'll be asked to speak to an operator and the operator will explain the steps you need to follow in order to fix the problems. It's all a scam, and will lead to you losing money and could lead to identity theft if you give them private financial information.
Utilities cutoff
You get a call from someone who claims that they are from your utility company, and they claim that your utilities will be shut off unless you immediately pay. The scammer will usually ask for payment via gift cards, although they may ask for payment in other ways, such as Western Union or bitcoin.
Relative in custody Scammer claims to be the police, and they have your son/daughtenephew/estranged twin in custody. You need to post bail (for some reason in iTunes gift cards or MoneyGram) immediately or the consequences will never be the same.
Mexican family scam
This scam comes in many different flavours, but always involves someone in your family and Mexico. Sometimes the scammer will claim that your family member has been detained, sometimes the scammer will claim that your family member has been kidnapped, and sometimes the scammer will claim that your family member is injured and needs help.
General family scams
Scammers will gather a large amount of information about you and target your family members using different stories with the goal of gettimg them to send money.
One ring scam
Scammers will call you from an international number with the goal of getting you to return their call, causing you to incur expensive calling fees.

## Online shopping scams

THE GOLDEN RULE OF ONLINE SHOPPING: If it sounds too good to be true, it probably is.
Dropshipping
An ad on reddit or social media sites like Facebook and Instagram offers items at huge discounts or even free (sometimes requiring you to reblog or like their page). They just ask you to pay shipping. The scam: The item will turn out to be very low quality and will take weeks or even months to arrive. Sometimes the item never arrives, and the store disappears or stops responding. The seller drop-ships the item from China. The item may only cost a few dollars, and the Chinese government actually pays for the shipping. You end up paying $10-$15 dollars for a $4 item, with the scammer keeping the profit. If you find one of these scams but really have your heart set on the item, you can find it on AliExpress or another Chinese retailer. Influencer scams A user will reach out to you on a social media platform, usually Instagram, and offer you the chance to partner with them and receive a free/discounted product, as long as you pay shipping. This is a different version of the dropshipping scam, and is just a marketing technique to get you to buy their products. Triangulation fraud Triangulation fraud occurs when you make a purchase on a site like Amazon or eBay for an item at a lower than market price, and receive an item that was clearly purchased new at full price. The scammer uses a stolen credit card to order your item, while the money from the listing is almost all profit for the scammer. Instagram influencer scams Someone will message you on Instagram asking you to promote their products, and offering you a discount code. The items are Chinese junk, and the offer is made to many people at a time. Cheap Items Many websites pop up and offer expensive products, including electronics, clothes, watches, sunglasses, and shoes at very low prices. The scam: Some sites are selling cheap knock-offs. Some will just take your money and run. What to do if you think you're involved with this scam: Contact your bank or credit card and dispute the charge. How to avoid: The sites often have every brand-name shoe or fashion item (Air Jordan, Yeezy, Gucci, etc) in stock and often at a discounted price. The site will claim to be an outlet for a major brand or even a specific line or item. The site will have images at the bottom claiming to be Secured by Norton or various official payment processors but not actual links. The site will have poor grammar and a mish-mash of categories. Recently, established websites will get hacked or their domain name jacked and turned into scam stores, meaning the domain name of the store will be completely unrelated to the items they're selling. If the deal sounds too good to be true it probably is. Nobody is offering brand new iPhones or Beats or Nintendo Switches for 75% off. Cheap Amazon 3rd Party Items You're on Amazon or maybe just Googling for an item and you see it for an unbelievable price from a third-party seller. You know Amazon has your back so you order it. The scam: One of three things usually happen: 1) The seller marks the items as shipped and sends a fake tracking number. Amazon releases the funds to the seller, and the seller disappears. Amazon ultimately refunds your money. 2) The seller immediately cancels the order and instructs you to re-order the item directly from their website, usually with the guarantee that the order is still protected by Amazon. The seller takes your money and runs. Amazon informs you that they do not offer protection on items sold outside of Amazon and cannot help you. 2) The seller immediately cancels the order and instructs you to instead send payment via an unused Amazon gift card by sending the code on the back via email. Once the seller uses the code, the money on the card is gone and cannot be refunded. How to avoid: These scammers can be identified by looking at their Amazon storefronts. They'll be brand new sellers offering a wide range of items at unbelievable prices. Usually their Amazon names will be gibberish, or a variation on FIRSTNAME.LASTNAME. Occasionally however, established storefronts will be hacked. If the deal is too good to be true its most likely a scam. Scams on eBay There are scams on eBay targeting both buyers and sellers. As a seller, you should look out for people who privately message you regarding the order, especially if they ask you to ship to a different address or ask to negotiate via text/email/a messaging service. As a buyer you should look out for new accounts selling in-demand items, established accounts selling in-demand items that they have no previous connection to (you can check their feedback history for a general idea of what they bought/sold in the past), and lookout for people who ask you to go off eBay and use another service to complete the transaction. In many cases you will receive a fake tracking number and your money will be help up for up to a month. Scams on Amazon There are scams on Amazon targeting both buyers and sellers. As a seller, you should look out for people who message you about a listing. As a buyer you should look out for listings that have an email address for you to contact the person to complete the transaction, and you should look out for cheap listings of in-demand items. Scams on Reddit Reddit accounts are frequently purchased and sold by fraudsters who wish to use the high karma count + the age of the account to scam people on buy/sell subreddits. You need to take precautions and be safe whenever you are making a transaction online. Computer scams Virus scam A popup or other ad will say that you have a virus and you need to follow their advice in order to remove it. They are lying, and either want you to install malware or pay for their software. ## Assorted scams Chinese Brushing / direct shipping If you have ever received an unsolicited small package from China, your address was used to brush. Vendors place fake orders for their own products and send out the orders so that they can increase their ratings. Money flipping Scammer claims to be a banking insider who can double/triple/bazoople any amount of money you send them, with no consequences of any kind. Obviously, the money disappears into their wallet the moment you send it. ## Door to door scams As a general rule, you should not engage with door to door salesmen. If you are interested in the product they are selling, check online first. Selling Magazines Someone or a group will come to your door and offer to sell a magazine subscription. Often the subscriptions are not for the duration or price you were told, and the magazines will often have tough or impossible cancellation policies. Energy sales Somebody will come to your door claiming to be from an energy company. They will ask to see your current energy bill so that they can see how much you pay. They will then offer you a discount if you sign up with them, and promise to handle everything with your old provider. Some of these scammers will "slam" you, by using your account number that they saw on your bill to switch you to their service without authorization, and some will scam you by charging higher prices than the ones you agreed on. Security system scams Scammers will come to your door and ask about your security system, and offer to sell you a new one. These scammers are either selling you overpriced low quality products, or are casing your home for a future burglary. They ask to enter your home While trying to sell you whatever, they suddenly need to use your bathroom, or they've been writing against the wall and ask to use your table instead. Or maybe they just moved into the neighborhood and want to see how you decorate for ideas. They're scoping out you and your place. They want to see what valuables you have, how gullible you are, if you have a security system or dogs, etc. ## Street scams Begging With a Purpose "I just need a few more dollars for the bus," at the bus station, or "I just need$5 to get some gas," at a gas station. There's also a variation where you will be presented with a reward: "I just need money for a cab to get uptown, but I'll give you sports tickets/money/a date/a priceless vase."
Three Card Monte, Also Known As The Shell Game
Unbeatable. The people you see winning are in on the scam.
Drop and Break
You bump into someone and they drop their phone/glasses/fancy bottle of wine/priceless vase and demand you pay them back. In reality, it's a $2 pair of reading glasses/bottle of three-buck-chuck/tasteful but affordable vase. CD Sales You're handed a free CD so you can check out the artist's music. They then ask for your name and immediately write it on the CD. Once they've signed your name, they ask you for money, saying they can't give it to someone else now. Often they use dry erase markers, or cheap CD sleeves. Never use any type of storage device given to you by a random person, as the device can contain malware. White Van Speaker Scam You're approached and offered speakers/leather jackets/other luxury goods at a discount. The scammer will have an excuse as to why the price is so low. After you buy them, you'll discover that they are worthless. iPhone Street Sale You're approached and shown an iPhone for sale, coming in the box, but it's open and you can see the phone. If you buy the phone, you'll get an iPhone box with no iPhone, just some stones or cheap metal in it to weigh it down. Buddhist Monk Pendant A monk in traditional garb approaches you, hands you a gold trinket, and asks for a donation. He holds either a notebook with names and amounts of donation (usually everyone else has donated$5+), or a leaflet with generic info. This is fairly common in NYC, and these guys get aggressive quickly.
Friendship Bracelet Scam More common in western Europe, you're approached by someone selling bracelets. They quickly wrap a loop of fabric around your finger and pull it tight, starting to quickly weave a bracelet. The only way to (easily) get it off your hand is to pay. Leftover sales
This scam involves many different items, but the idea is usually the same: you are approached by someone who claims to have a large amount of excess inventory and offers to sell it to you at a great price. The scammer actually has low quality items and will lie to you about the price/origin of the items.
Dent repair scams
Scammers will approach you in public about a dent in your car and offer to fix it for a low price. Often they will claim that they are mechanics. They will not fix the dent in your car, but they will apply large amounts of wax or other substances to hide the dent while they claim that the substance requires time to harden.
Gold ring/jewelry/valuable item scam
A scammer will "find" a gold ring or other valuable item and offers to sell it to you. The item is fake and you will never see the scammer again.
Distraction theft
One person will approach you and distract you, while their accomplice picks your pockets. The distraction can take many forms, but if you are a tourist and are approached in public, watch closely for people getting close to you.

## General resources

Site to report scams in the United Kingdom: http://www.actionfraud.police.uk/
Site to report scams in the United States: https://www.ic3.gov/default.aspx
Site to report scams in Canada: www.antifraudcentre-centreantifraude.ca/reportincident-signalerincident/index-eng.htm
Site to report scams in Europe: https://www.europol.europa.eu/report-a-crime/report-cybercrime-online
Microsoft's anti-scam guide: https://www.microsoft.com/en-us/safety/online-privacy/avoid-phone-scams.aspx
https://www.usa.gov/common-scams-frauds
https://www.usa.gov/scams-and-frauds
https://www.fbi.gov/scams-and-safety/common-fraud-schemes

 Our first post gave a short summary of our tokens’ functionality. This post is intended to give more background and reasoning for design decisions. Note: This post is out of date. Please see The Many Faces of an $OWL blog post for the latest on OWL use cases. Background One of Bitcoin’s critical innovations was the addition of an incentive model to a peer-to-peer network protocol. Using a native currency and Proof of Work dispersion mechanism, Bitcoin rewards its workers and makes it incentive compatible for disparate parties to work together toward a common goal. In addition, using a native currency allows for protocol monetization. With SMTP for example, most work is done on the protocol layer, however all value is created on the application layer. The rapidly evolving world of cryptocurrencies has wasted no time in innovating this concept into a variety of “app” or “protocol” token models. In the initial “altcoin” stage of these models, tokens are dispensed similarly to Bitcoin and there is no unique utility within the network for these tokens. More recently, protocols with unique applications have iterated on this design with new dispersion mechanisms and uses for the coins within the protocol itself. Gnosis will follow this approach, hopefully with a few successful innovations of our own. Building a sustainable ecosystem for token holders, participants, and application developers on a platform level cryptoeconomic system is difficult to achieve. Smart contracts are only as valuable as people’s trust in their verifiable execution. In order to achieve this trust, the code almost always needs to be made open source. Even if not made immediately open source, once deployed to the Ethereum network the bytecode can potentially be read and decompiled. Once this code is open source, it can be easily replicated and deployed with its own incentive model. Herein lies the dilemma: what incentivizes new participants to use the existing network, rather than copy the code and remove the fees (or set their own fees)? The developing answer to this problem is network effect. We use Bitcoin and Ethereum, rather than forks of these protocols, due to the benefits provided by interoperability with other applications, services, and participants on the network. This argument extends beyond cryptoeconomics to markets and money in general. Money and markets become more useful and competitive as more people use them. eBay charges an inordinate amount of fees, however buyers and sellers still use it due to the critical mass on the platform. This network effect enables buyers to connect to sellers and vice versa for specialized products. While network effect serves as a fundamental component driving Gnosis platform use, we believe that it’s important to take this a step further. The Gnosis platform will be composed of three primary layers: Core, Services, and Application. The Gnosis Layers https://preview.redd.it/yblr0t76n7a51.png?width=700&format=png&auto=webp&s=d42a14c0e692ba55ee7cfbcff183c84649816dac Layer One: Gnosis Core The Core layer provides the foundational smart contracts for Gnosis use: event token creation and settlement, a market mechanism, oracle, and a management interface. This layer is and always will be free and open to use. Creating new markets is near zero marginal cost, and to remain competitive fees will have to approach zero. Instead of grasping at the maximum possible fees while remaining competitive, we feel that it is prudent to eliminate fees at the most basic contract level. It should be in every party’s best interest to use the existing open source and feeless contracts instead of deploying their own version. Layer Two: Gnosis Services The Gnosis Services layer will offer additional services on top of Gnosis Core and will use a trading fee model. These services will include a state channel implementation, new market mechanisms, stablecoin and payment processor integrations, open source template applications, application customization tools, and the oracle marketplace. More features may be introduced as deemed useful. These components are necessary for most consumer applications building on Gnosis. State channels are a prerequisite for betting and financial applications requiring thousands or more transactions per second. Without stablecoins, market participants are subject to the volatility of the cryptocurrency which the market is denominated in and the event outcome that they are predicting. Application templates, customization tools, and advanced oracle selection will allow us to execute on our vision of lowering the barrier to entry for new prediction market based applications by at least two orders of magnitude. While some applications and participants will interact with Gnosis on the Core level, we are confident that these services will provide a compelling reason for Services level use. Layer Three: Gnosis Applications On top of the Services layer (or in some cases, just Gnosis Core) is the Gnosis application layer. These applications are primarily front-ends that target a particular prediction market use case and or customer segment. Some of these applications may be built by Gnosis, while others will be built by third parties. Our vision for Gnosis is to have a wide variety of prediction market applications built atop the same platform and liquidity pool. These applications will likely charge additional fees or use alternative business models such as market making, information selling, or advertising. As we’ll see in the next section on tokens, many Gnosis applications may include token holding as a core component of their business model. Introducing the Tokens of the Realm: GNO and OWL The token sold during the token launch is known as the Gnosis Token, or GNO. This is the only time that these tokens can be created, and therefore the total supply of GNO is fixed. Fees, similar to those of a trading market, will be charged to participants on the Gnosis Services and Applications layers (but as a reminder, not the bare bones Core layer). These fees will initially be denominated in cryptocurrency, namely BTC or ETH. Gnosis seeks to not only create interesting software, but also a community of those interested in sharing their wisdom on Gnosis markets. To do this, we needed to create a model that lowers the barrier to entry for repeat users (e.g. having to pay BTC/ETH repeatedly). Therefore, in addition to paying this fee in BTC or ETH, Gnosis ecosystem participants will be able to pay the fee in OWL tokens. Gnosis OWL can be used to pay platform fees on the Services layer, subsidize the fees of other participants, provide initial subsidies for markets, or for market trading. OWL will be pegged to$1 USD worth of fees. In this way, OWL acts as a coupon for $1 of use within Gnosis. Gnosis tokens (GNO) are the generator for OWL creation. OWL can only be created via activating the utility of the Gnosis (GNO) tokens. This is done via a smart contract system. The smart contract works as follows: GNO token holders agree to “lock” their tokens in a smart contract (30–365 days). A multiplier is added for longer lock durations. The smart contract determines the user selected lock duration and applies that duration to a formula that is designed to regulate the supply of OWL tokens currently in use. Prior to locking their GNO tokens in the smart contract, users will be able to see exactly how much OWL they will receive as a result of executing the smart contract. Once users execute the contract, 30% of their OWL will be distributed for immediate use, and the remaining 70% will be distributed proportionally over the locked duration. Once the lock duration expires, the locked GNO ceases to generate OWL and the GNO becomes freely transferable by the holder. There is no limit (other than duration) for how many times GNO tokens may be used to create OWL. How Can Gnosis Remain Viable if Participants Choose Not to Pay in OWL? A core value proposition of Gnosis (and decentralization) is to guarantee future characteristics of platforms to both users and developers without relying on the trustworthiness of an operating company. In order to do this, elements including fee rates, must be codified into the software itself. It is expected that OWL will be the overwhelmingly predominant method for paying fees in the Gnosis ecosystem. In the unexpected event that this is not true, and users are paying in BTC or ETH, the platform may become vulnerable to low-fee copycats or potentially even illegal forks of the Gnosis codebase. These alternative platforms may logically cause erosion of the Gnosis userbase, subsequently triggering justified loss of developer confidence that their created markets and applications will remain viable on Gnosis. In order to avoid this scenario, we designed a fee-reduction mechanism to bolster competitiveness of the Gnosis platform. The result is added confidence for developers and partners that Gnosis is the infrastructure they should be building markets on. NOTE: It is unlikely that this mechanism will be used as game theory and expectations point to users predominantly paying fees in OWL. In the event this mechanism is triggered, we expect the occurrence to be extremely rare. Two core requirements for the mechanism is that it is both decentralized and costly. The mechanism must be costly in order to eliminate spam or manipulation. The core functionality of the mechanism is as follows: All fees paid in BTC/ETH/Tokens go to an auction contract outside the control of the Gnosis team. If fees exist in the auction contract, any GNO token holder can submit a bid, bidding their held GNO against some amount of fees contained in the auction contract. If the bid is accepted, the GNO will then enter the auction contract and the user will receive the fees specified. When the user’s GNO enters the auction contract, the fee reduction mechanism will be triggered causing a reduction in fees on Gnosis proportional to the total amount of GNO held in this auction contract. The auction contract is one-way and GNO cannot leave this wallet. ​ https://preview.redd.it/pi8hphw9n7a51.png?width=700&format=png&auto=webp&s=3f083a291992e83b486630f5a848e09ca977569e Examples of GNO and OWL Utility Let’s take a look at several example uses for OWL: Alice is a Gnosis user who also holds GNO tokens. She locks down a portion of her Gnosis tokens for a year period. Every day she receives some OWL tokens. She uses these OWL tokens to pay her trading fees. BobBets seeks to build a sports betting application on Gnosis. BobBets purchases Gnosis tokens during the token launch. BobBets locks these tokens to create OWL. When BobBets creates markets, they also deposit a portion of OWL to the market to subsidize fees for their users. Claire likes to ask interesting questions. Markets on Gnosis must be provided with an initial subsidy to create shares. Claire funds these markets using OWL, and the platform matches (to a certain level) her OWL! Claire gets better answers to her questions because there is larger incentive for participants to provide insights. Conclusion We believe our dual token and Core/Services model is optimal to encourage adoption of the Gnosis platform. Adoption should be everyone’s number one goal toward the success of Gnosis as it both increases liquidity (leading to better odds, and encouraging a feedback loop leading to more reliable predictions) and awareness. By having the Gnosis Core layer fee free and with a pay once model by purchasing GNO for the Gnosis Services and Application layers, we can remain incentive compatible for all participants in the system. IMPORTANT INFORMATION GNO tokens are functional utility tokens within the Gnosis platform. GNO tokens are not securities. GNO tokens are non-refundable. GNO tokens are not for speculative investment. No promises of future performance or value are or will be made with respect to GNO, including no promise of inherent value, no promise of continuing payments, and no guarantee that GNO will hold any particular value. GNO tokens are not participation in the Company and GNO tokens hold no rights in said company. GNO tokens are sold as a functional good and all proceeds received by Company may be spent freely by Company absent any conditions. GNO tokens are intended for experts in dealing with cryptographic tokens and blockchain-based software systems. submitted by ensluck to Owltoken [link] [comments] ##### Nhom VBC CHROMIA AMA TRANSCRIPT (15/05/2020) Thai Nhat Minh | Stably: First of all, can you have a brief introduction about yourself as well as about Chromia? Henrik_hjelte, Sergelubkin Henrik Hjelte: Hello. My name is Henrik Hjelte. I am Co-Founder and CEO of Chromia. I have more than 30 years of experience in programming and a degree in Economics from Uppsala University. BTW economics and computers = blockchain, so finally found a job that fits me. I was introduced to the blockchain by the leader of the colored-coins project Alex Mizrahi in 2013 Colored coins project was a very influential thing It was the first way for user created tokens bolted on to the only blockchain at the time (almost) bitcoin We started ChromaWay 2014, with Or Perelman too, to explore if the world was interested in “tokens” and those kind of applications We worked with enterprise blockchain for some time, but now we are focused on Chromia, a new public platform for mainstream decentralized applications using relational blockchain technology. Ok, maybe I should tell something about Chromia and not myself too. Chromia is a better blockchain for building decentralized Apps. better because it follows the “normal worlds” way of managing data. A little history: I found a text/description to paste: Chromia is a brainchild of ChromaWay. ChromaWay has a long record of delivering pioneering projects around the world. We issued Euros on the Bitcoin blockchain with LHV bank, allowed investors to invest in startups in a wholly decentralized way with Funderbeam, digitized the title transfer process with the Swedish land registry, and mediated the green bond market. ChromaWay’s core team created the world’s first protocol to issue tokens already in 2012, when blockchain was called “bitcoin 2.0”. Then ChromaWay introduced the relational model to enterprise blockchains with a consortium database called Postchain. Now Postchain is going public as the foundation for Chromia, a better blockchain for building decentralised Apps. Chromia is a new public blockchain based on the idea of integrating traditional databases, Relational databases with blockchain security. Chromia is a general purpose blockchain with full smart contract capabilities, just that it is a lot easier to code, even complex applications. You code with an easy to learn new programming language that combines the power of SQL and normal languages but makes it secure in a blockchain context. Up to 1/10 the code-lines vs other blockchains. If you don’t believe me, check this blog (later, stay in the chat): https://blog.chromia.com/reasons-for-rell-compactness/ The aim of Chromia is to combine relational databases, which exist in every kind of organization, with blockchains. We want to provide a platform for our users to develop totally decentralized apps securely. Our goal is for Chromia to be seen as the number one infrastructure for decentralized applications. Think about it: blockchain is about managing data (in a shared context). And… What do we use to manage data? A Database! Serge: Sure! My name is Serge! And I work in Chromia marketing department. Also, I help coordinate various projects inside the company My background is in Economics and Marketing Thai Nhat Minh | Stably: Question 1️⃣ DApp is currently mainly concentrated in the field of games, and its life cycle is basically short, just like the Crypto Kitty is only hot for a while, how to dig the application of DApp in more fields and how to improve the utilization rate of DApp? u/henrik_hjelte u/sergelubkin Serge: Good one, let me answer Gaming is quite a challenging target because good UX is expected, it needs to be fast, responsive, etc. If we can do that, then we can also do all sorts of other stuff. Also, it lets us experiment with things without a lot of hassle, it’s easier to get users, and so on. It’s also a growing niche within blockchain. You can check our latest game, Mines of Dalarnia https://www.minesofdalarnia.com We also have Enterprise projects already, for example Green Assets Wallet https://greenassetswallet.org/about that already launched on the first Mainnet version called Bootstrap Net,we also have https://capchap.se built on our tech, more projects like non-profit review platform Impactoria, public land registries, medical projects and so on Also don’t forget about our fully decentralized social network/forum that is live already on the testnet https://testnet.chromunity.com. Thai Nhat Minh | Stably: Question 2️⃣ How will dapp face the world change after the epidemic? u/henrik_hjelte u/sergelubkin Henrik Hjelte: Nobody can say for sure, but maybe people will tend to be online more than offline, so demand on online products and dapps as well will increase. I just came in from an internal demo of a secret project we do, and it can be seen as a way to hang out online (a bit cryptic answer) There are also interesting use cases of dapps in the medical field. For example, we participated in the world-wide hackathon Hack for Sweden. Where our submission was to create an app on Chromia blockchain that increases the coordination between countries and hospitals especially during the hard time and COVID19. Chromia wants to help the European Union (and the world, but we saw problems in the EU…) and its citizens to provide transparency over the necessary medical and protective devices and appliances of which we see shortage during this emergency crisis. You can watch our promo here https://twitter.com/chromaway/status/1247557274337447938?s=20. For me it was a fun Hackathon too because for once I got the opportunity to code… I told everyone else I will not do any bossing… We try to continue this path on medical applications a bit. Thai Nhat Minh | Stably: Question 3️⃣ DApps are still not directly embedded in mobile phones like Apps at this moment, and DApps have also been flooded with bet content. How can guests increase the use of DApps and lower the threshold for using DApps? u/henrik_hjelte u/sergelubkin Serge: The answer is — better User Experience. We believe that in order for a DApp to be usable and become more widely accepted it has to feel like a normal App. A DApp needs to have quick transactions, scale well & shouldn’t require users to pay for each transaction. This is something that is possible now with using Chromia. It’s an extremely exciting time since we are going to see a new generation of DApps. On top of that, we think that we might have an ace coming up. We have built a game to demonstrate the powers and possibilities of Chromia. A little bit about the game: In Mines of Dalarnia (https://www.minesofdalarnia.com), players get to explore the vast expanses of interplanetary treasure mines. With an innovative Dalarnia Token system, players can purchase virtual mining plots, and put them up for rent into the community, allowing for real-estate tycoons to earn more Tokens. Mining plots can also undergo their own upgrades, making them more lucrative to explore, as well as a hot property for rental by miners. The game takes advantage of these NFT-based tokens to securely track exchanges, and provide a sense of ownership and wealth to players as they grow their mining and resource empire. Watch our trailer https://youtu.be/bDXKOp1Asqw and sign-up for the TestNet on the website! Thai Nhat Minh | Stably: Question 4️⃣ Many practitioners think that the main reason for restricting the development of DApp is “incomplete infrastructure”. How effective is the current “cross-chain” and “side-chain” solution? u/henrik_hjelte u/sergelubkin Serge: Our infrastructure resembles Alibaba Cloud, so a DApp developer just goes and deploys his DApp’s blockchain into it, it’s easy. Also our language Rell https://rell.chromia.com/en/maste is more robust than any other blockchain programming language.Or Azure or AWS Rell combines the following features: 1. Relational data modeling and queries similar to SQL. People familiar with SQL should feel at home once they learn the new syntax. 2. Normal programming constructs: variables, loops, functions, collections, etc. 3. Constructs which specifically target application backends and, in particular, blockchain-style programming including request routing, authorization, etc. Rell aims to make programming as convenient and simple as possible. It minimizes boilerplate and repetition. At the same time, as a static type system it can detect and prevent many kinds of defects prior to run-time. Maybe Henrik wants to add something. :) Henrik Hjelte: Yes, I can add some thing Consider again the real /normal world. What made the apps you use every day? Behind the bank app is a relational database. Web 1.0, “shopping on the internet” was a relational database hooked up to a webpage. web 2.0: Thefacebook was PhP and MySQL hack again, a relational database. So, we aim to make it just as easy to do decentralized apps as normal apps. Also “the cloud” inspiration is more normal. In Chromia, the dapp developer pays for hosting the application (normally). Not the USERS. No gas,this is a big usability improvement. Thai Nhat Minh | Stably: Question 5️⃣ There are many DApp development platforms on the market. What are the competitive advantages of Chromia? It can be explained in terms of development cost and ease of use that everyone is more concerned about. u/henrik_hjelte u/sergelubkin Henrik Hjelte: This what I’m talking about. I think “Ease of use” combined with “Power” is our biggest strength. Easiness is our core feature thanks to the relational database aspect of our system. Relational databases are run by 85% of the enterprise market at the moment. And used in 100% of all organizations. The largest vendor on that market Oracle, has a bigger market cap than bitcoin, So, this makes it easy for enterprises to integrate our tech stack to their normal systems without the need to redo them, like in most cases where blockchain pilots have failed. That’s partially why we had success with enterprise customer which are live in the Chromia network. And: there is a large set of features that relational databases have that alternatives (noSQL) do not have or do not do as well. And blockchain is very primitive compared to that. Data indepence, mathematical foundations etc. Large books have been written about it… On Chromiam It’s very easy for developers to deploy DApps because they already know SQL-style programming. Keep in mind that we worked with customers and developers to build our tech stack while solving problems for them. We didn’t build something unneeded, we had proof of validation from the market. SQL is top 3rd language in the world (after HTML and javascript). source: stackoverflow survey 2019, among 90 000 developers… Top 4 used databases: different flavors of SQL (relational databases) So, they are used for a reason: Ease of use/programming, power etc. Also, Rell is our language, is statically typed (means bugs are discovered when programs are written rather than we they run). It is also more compact, up to 1/7 of the code lines of SQL. And have “normal” programming constructs + blockchain programming built in. Because we require both relational database properties and more security than SQL, currently Rell is the only choice. It is really easy to learn, please go check https://rell.chromia.com/en/maste. Chromia also provides news to the database developer community…. millions of developers in potential. OK, bear this in mind when you wonder how we can compete with blockchain X… Blockchain X is a fart in the ocean compare to the SQL world 😊 Bach Tuyet You have organized many AMA sessions to the international community in general and Vietnam in particular. What do you most want to get after AMA sessions from the community? u/henrik_hjelte Sergey I’ll take this one:) our goal is to grow the community 1. We want people to join our channels such as telegram, twitter, email also our decentralized forum https://testnet.chromunity.com and participate in discussions 2. We want people to try our dapps such as Mines of Dalarnia 3. We want to get feedback and understand the most important issues people care about Chromia and the blockchain industry in general 4. We want to get more developers building on top of Chromia LBTS: What was your motivation for creating RELL and not use other languages? What benefits? Why name it RELL also? Henrik Hjelte: We have a private/federated relational blockchain called Postchain, and it allows SQL. But that can work in a small environment when you know all parties, and if you are really careful in checking code. But not for a more secure, distributed on the web setup, so we had to make it more secure (Deterministic, statically typed). In the process, we also took the opportunity to make it cool and nice. Also: it is simply not possibly to use evm, jvm, or web assembly. We need/want a database in the bottom. Postgresql is our virtual machine. You do not reimplement that…. 10+ years codebase…. Lee: Being part of the gamer community, I would like to know what you would think about collaborating with a MOBA, RPG or Arcade game or some kind of project? Henrik Hjelte: We are already collaborating with some smaller studios. For bigger fish, we want to show them what is completely unique and visionary with Chromia, and we think we need various examples. So, first arcade game MoD (linked above) is one example, it is not the full potential or anything but a start. In this summer, krystopia 2 a puzzle game from Antler Interactive will be released. What is even cooler is the “demo project” we do together with them, where we will show how a mutliplayer game with real blockchain features will work. I just saw it an hour ago and was blown away OH, and there is another studio releasing something very cool. Full logic on chain strategy game. Chain of Alliance. oyibo pepper: Do you encourage HACKATHON programs for intending Developers to test their skills and build on RELL Can you explain more about CHROMIA AMBASSADORS PROGRAM, CAN I BECOME AN AMBASSADOR Serge: Yes, you can, but you will need to change your avatar 🤣 Seriously, we are growing our Chromians community if you want to become one please ping our admins in Chromia telegram group. Also, we are planning virtual hackathons soon, please subscribe to stay updated Infinite Crypto: Since the Chromia project is currently working on the Ethereum blockchain ERC20 standard! But we know that there are a lot of scalability issues with Ethereum, so why would you choose the Ethereum blockchain over other scalable blockchains? Do you have any plans for Mainnet launch of Chromia? Henrik Hjelte: ETH is just used in a pre-phase for tokens. We will have our own mainnet tokens interchangable with ETH. Oyinbo pepper What’s CHROMIA SSO and SDK, how can I get started Henrik Hjelte Both are 3 letters. That is what they have in common. SDK = software development kit, check docs on https://rell.chromia.com SSO = single sign on. A unique UX improvement. You approve an app in your wallet (vault) with super ease. no need to remember codes sso: https://blog.chromia.com/chromia-sso-the-whys-and-the-whats/ We have a fundamentally different model from bitcoin and ethereum and the likes. The blockchain is not run by anonymous computers in basement and student dorms across the world. We have more of known identities, so 51% attacks is protected not by PoW/PoS but other consensus. Please see our whitepaper. Note that we are not noobs when it comes to this, our CTO Alex has published papers in academic journals on consensus etc. from 2013, and done several important ideas for blockchain. Sidechains we think he was first with, tokens too. Sheron Fernando: Is there any plan to makes partnership with local cryptocurrency developers from each country to make$CHR usage more worldwide?
Serge:
Yes, we are looking for cooperation with more external developers. Send me a message if you are interested in developing something on Chromia.
Stella:
What are the underlying problems in the Dapps today that can be solved with the Chromia protocol?
Serge:
1. Scalability — on Chromia your dapp can have unlimited numbers of users thanks to parallel scaling
2. Easiness of use — you don’t need external wallets, no need to buy crypto to pay for gas etc
3. Cost — in general to deploy the dapp and to use the dapp
Marcel Lagacé:
Why build this platform? What is Chromia mission? What are the most prominent features of the platform? Can you clarify the use case for this feature?
Henrik Hjelte:
We build the platform to fix the problems with blockchains, that we ourselves have experienced since 2014 (before ethereum existed).
LBTS:
Can you tell us about Chromia developers? How motivated and experienced are they to always deliver the best products?
Henrik Hjelte:
I can tell you that we recruit developers that are really good, from all parts of the world. Vietnam has been a hub because we found many good, so in Ukraine.
How can we say “we have so good developers”? First one thing that is a bit different is that we are pretty experienced in leadership team of development. I do not code much anymore since I’m a CEO. But I do have now over 30 years of experience. Got published and was payed when I was 15. First full-time professional developer job at 18. Have released open-source projects used by 10: s of thousand developers.
And Alex, our CTO is Extremely good. That is why I recruited him to my old startup 2006 or so… So: we have experience to sort out good developers from bad.
Marcel Lagacé:
Does Chromia staking model is different from other staking platform??
What are the beneficial advantages of chromia staking system?
Serge:
The main difference is that we have independent Providers, entities that are not connected. These serious players are exchanges, data centres, professional staking companies. They provide a backbone of the ecosystem and host dapps. Like Amazon servers in the cloud. They cannot have stake bigger than the maximum thus they can’t control the network. This is probably the main difference with classic DPoS networks
Nguyen Duy Bao:
A lot of people will want to know what the strength of Chromia is but I want to know the weaknesses and problems Chromia faces ? How do you plan to solve it?
Henrik Hjelte:
A weakness I guess is weak compared to “competition”. And there are some blockchain projects that got crazy amount of funding. So how can we compete with that, when they can hire more developers for example? Well here is what experience comes into play: More developers does not always increase productivity a lot, it is diminishing returns. You can see many large projects, with 100 of developers fail miserably with no results.
And actually, sometimes true with marketing spend too. It is generally good with money, but if you are a bit clever you can compete also on marketing with less money than your competition.
Website: https://www.chromia.com
Telegram: https://t.me/hellochromia
Decentralized Social network Chromunity: https://testnet.chromunity.com
Free-to-Play Blockchain Game Mines of Dalarnia: https://www.minesofdalarnia.com

##### Dive Into Tendermint Consensus Protocol (I)

This article is written by the CoinEx Chain lab. CoinEx Chain is the world’s first public chain exclusively designed for DEX, and will also include a Smart Chain supporting smart contracts and a Privacy Chain protecting users’ privacy.
longcpp @ 20200618
This is Part 1 of the serialized articles aimed to explain the Tendermint consensus protocol in detail.
Part 1. Preliminary of the consensus protocol: security model and PBFT protocol
Part 2. Tendermint consensus protocol illustrated: two-phase voting protocol and the locking and unlocking mechanism
Part 3. Weighted round-robin proposer selection algorithm used in Tendermint project
Any consensus agreement that is ultimately reached is the General Agreement, that is, the majority opinion. The consensus protocol on which the blockchain system operates is no exception. As a distributed system, the blockchain system aims to maintain the validity of the system. Intuitively, the validity of the blockchain system has two meanings: firstly, there is no ambiguity, and secondly, it can process requests to update its status. The former corresponds to the safety requirements of distributed systems, while the latter to the requirements of liveness. The validity of distributed systems is mainly maintained by consensus protocols, considering the multiple nodes and network communication involved in such systems may be unstable, which has brought huge challenges to the design of consensus protocols.

## The semi-synchronous network model and Byzantine fault tolerance

Researchers of distributed systems characterize these problems that may occur in nodes and network communications using node failure models and network models. The fail-stop failure in node failure models refers to the situation where the node itself stops running due to configuration errors or other reasons, thus unable to go on with the consensus protocol. This type of failure will not cause side effects on other parts of the distributed system except that the node itself stops running. However, for such distributed systems as the public blockchain, when designing a consensus protocol, we still need to consider the evildoing intended by nodes besides their failure. These incidents are all included in the Byzantine Failure model, which covers all unexpected situations that may occur on the node, for example, passive downtime failures and any deviation intended by the nodes from the consensus protocol. For a better explanation, downtime failures refer to nodes’ passive running halt, and the Byzantine failure to any arbitrary deviation of nodes from the consensus protocol.
Compared with the node failure model which can be roughly divided into the passive and active models, the modeling of network communication is more difficult. The network itself suffers problems of instability and communication delay. Moreover, since all network communication is ultimately completed by the node which may have a downtime failure or a Byzantine failure in itself, it is usually difficult to define whether such failure arises from the node or the network itself when a node does not receive another node's network message. Although the network communication may be affected by many factors, the researchers found that the network model can be classified by the communication delay. For example, the node may fail to send data packages due to the fail-stop failure, and as a result, the corresponding communication delay is unknown and can be any value. According to the concept of communication delay, the network communication model can be divided into the following three categories:
• The synchronous network model: There is a fixed, known upper bound of delay $\Delta$ in network communication. Under this model, the maximum delay of network communication between two nodes in the network is $\Delta$. Even if there is a malicious node, the communication delay arising therefrom does not exceed $\Delta$.
• The asynchronous network model: There is an unknown delay in network communication, with the upper bound of the delay known, but the message can still be successfully delivered in the end. Under this model, the network communication delay between two nodes in the network can be any possible value, that is, a malicious node, if any, can arbitrarily extend the communication delay.
• The semi-synchronous network model: Assume that there is a Global Stabilization Time (GST), before which it is an asynchronous network model and after which, a synchronous network model. In other words, there is a fixed, known upper bound of delay in network communication $\Delta$. A malicious node can delay the GST arbitrarily, and there will be no notification when no GST occurs. Under this model, the delay in the delivery of the message at the time $T$ is $\Delta + max(T, GST)$.
The synchronous network model is the most ideal network environment. Every message sent through the network can be received within a predictable time, but this model cannot reflect the real network communication situation. As in a real network, network failures are inevitable from time to time, causing the failure in the assumption of the synchronous network model. Yet the asynchronous network model goes to the other extreme and cannot reflect the real network situation either. Moreover, according to the FLP (Fischer-Lynch-Paterson) theorem, under this model if there is one node fails, no consensus protocol will reach consensus in a limited time. In contrast, the semi-synchronous network model can better describe the real-world network communication situation: network communication is usually synchronous or may return to normal after a short time. Such an experience must be no stranger to everyone: the web page, which usually gets loaded quite fast, opens slowly every now and then, and you need to try before you know the network is back to normal since there is usually no notification. The peer-to-peer (P2P) network communication, which is widely used in blockchain projects, also makes it possible for a node to send and receive information from multiple network channels. It is unrealistic to keep blocking the network information transmission of a node for a long time. Therefore, all the discussion below is under the semi-synchronous network model.
The design and selection of consensus protocols for public chain networks that allow nodes to dynamically join and leave need to consider possible Byzantine failures. Therefore, the consensus protocol of a public chain network is designed to guarantee the security and liveness of the network under the semi-synchronous network model on the premise of possible Byzantine failure. Researchers of distributed systems point out that to ensure the security and liveness of the system, the consensus protocol itself needs to meet three requirements:
• Validity: The value reached by honest nodes must be the value proposed by one of them
• Agreement: All honest nodes must reach consensus on the same value
• Termination: The honest nodes must eventually reach consensus on a certain value
Validity and agreement can guarantee the security of the distributed system, that is, the honest nodes will never reach a consensus on a random value, and once the consensus is reached, all honest nodes agree on this value. Termination guarantees the liveness of distributed systems. A distributed system unable to reach consensus is useless.

## The CAP theorem and Byzantine Generals Problem

In a semi-synchronous network, is it possible to design a Byzantine fault-tolerant consensus protocol that satisfies validity, agreement, and termination? How many Byzantine nodes can a system tolerance? The CAP theorem and Byzantine Generals Problem provide an answer for these two questions and have thus become the basic guidelines for the design of Byzantine fault-tolerant consensus protocols.
Lamport, Shostak, and Pease abstracted the design of the consensus mechanism in the distributed system in 1982 as the Byzantine Generals Problem, which refers to such a situation as described below: several generals each lead the army to fight in the war, and their troops are stationed in different places. The generals must formulate a unified action plan for the victory. However, since the camps are far away from each other, they can only communicate with each other through the communication soldiers, or, in other words, they cannot appear on the same occasion at the same time to reach a consensus. Unfortunately, among the generals, there is a traitor or two who intend to undermine the unified actions of the loyal generals by sending the wrong information, and the communication soldiers cannot send the message to the destination by themselves. It is assumed that each communication soldier can prove the information he has brought comes from a certain general, just as in the case of a real BFT consensus protocol, each node has its public and private keys to establish an encrypted communication channel for each other to ensure that its messages will not be tampered with in the network communication, and the message receiver can also verify the sender of the message based thereon. As already mentioned, any consensus agreement ultimately reached represents the consensus of the majority. In the process of generals communicating with each other for an offensive or retreat, a general also makes decisions based on the majority opinion from the information collected by himself.
According to the research of Lamport et al, if there are 1/3 or more traitors in the node, the generals cannot reach a unified decision. For example, in the following figure, assume there are 3 generals and only 1 traitor. In the figure on the left, suppose that General C is the traitor, and A and B are loyal. If A wants to launch an attack and informs B and C of such intention, yet the traitor C sends a message to B, suggesting what he has received from A is a retreat. In this case, B can't decide as he doesn't know who the traitor is, and the information received is insufficient for him to decide. If A is a traitor, he can send different messages to B and C. Then C faithfully reports to B the information he received. At this moment as B receives conflicting information, he cannot make any decisions. In both cases, even if B had received consistent information, it would be impossible for him to spot the traitor between A and C. Therefore, it is obvious that in both situations shown in the figure below, the honest General B cannot make a choice.
According to this conclusion, when there are $n$ generals with at most $f$ traitors (n≤3f), the generals cannot reach a consensus if $n \leq 3f$; and with $n > 3f$, a consensus can be reached. This conclusion also suggests that when the number of Byzantine failures $f$ exceeds 1/3 of the total number of nodes $n$ in the system $f \ge n/3$ , no consensus will be reached on any consensus protocol among all honest nodes. Only when $f < n/3$, such condition is likely to happen, without loss of generality, and for the subsequent discussion on the consensus protocol, $n \ge 3f + 1$ by default.
The conclusion reached by Lamport et al. on the Byzantine Generals Problem draws a line between the possible and the impossible in the design of the Byzantine fault tolerance consensus protocol. Within the possible range, how will the consensus protocol be designed? Can both the security and liveness of distributed systems be fully guaranteed? Brewer provided the answer in his CAP theorem in 2000. It indicated that a distributed system requires the following three basic attributes, but any distributed system can only meet two of the three at the same time.
1. Consistency: When any node responds to the request, it must either provide the latest status information or provide no status information
2. Availability: Any node in the system must be able to continue reading and writing
3. Partition Tolerance: The system can tolerate the loss of any number of messages between two nodes and still function normally

https://preview.redd.it/1ozfwk7u7m851.png?width=1400&format=png&auto=webp&s=fdee6318de2cf1c021e636654766a7a0fe7b38b4
A distributed system aims to provide consistent services. Therefore, the consistency attribute requires that the two nodes in the system cannot provide conflicting status information or expired information, which can ensure the security of the distributed system. The availability attribute is to ensure that the system can continuously update its status and guarantee the availability of distributed systems. The partition tolerance attribute is related to the network communication delay, and, under the semi-synchronous network model, it can be the status before GST when the network is in an asynchronous status with an unknown delay in the network communication. In this condition, communicating nodes may not receive information from each other, and the network is thus considered to be in a partitioned status. Partition tolerance requires the distributed system to function normally even in network partitions.
The proof of the CAP theorem can be demonstrated with the following diagram. The curve represents the network partition, and each network has four nodes, distinguished by the numbers 1, 2, 3, and 4. The distributed system stores color information, and all the status information stored by all nodes is blue at first.
1. Partition tolerance and availability mean the loss of consistency: When node 1 receives a new request in the leftmost image, the status changes to red, the status transition information of node 1 is passed to node 3, and node 3 also updates the status information to red. However, since node 3 and node 4 did not receive the corresponding information due to the network partition, the status information is still blue. At this moment, if the status information is queried through node 2, the blue returned by node 2 is not the latest status of the system, thus losing consistency.
2. Partition tolerance and consistency mean the loss of availability: In the middle figure, the initial status information of all nodes is blue. When node 1 and node 3 update the status information to red, node 2 and node 4 maintain the outdated information as blue due to network partition. Also when querying status information through node 2, you need to first ask other nodes to make sure you’re in the latest status before returning status information as node 2 needs to follow consistency, but because of the network partition, node 2 cannot receive any information from node 1 or node 3. Then node 2 cannot determine whether it is in the latest status, so it chooses not to return any information, thus depriving the system of availability.
3. Consistency and availability mean the loss of the partition tolerance: In the right-most figure, the system does not have a network partition at first, and both status updates and queries can go smoothly. However, once a network partition occurs, it degenerates into one of the previous two conditions. It is thus proved that any distributed system cannot have consistency, availability, and partition tolerance all at the same time.

The discovery of the CAP theorem seems to declare that the aforementioned goals of the consensus protocol is impossible. However, if you’re careful enough, you may find from the above that those are all extreme cases, such as network partitions that cause the failure of information transmission, which could be rare, especially in P2P network. In the second case, the system rarely returns the same information with node 2, and the general practice is to query other nodes and return the latest status as believed after a while, regardless of whether it has received the request information of other nodes. Therefore, although the CAP theorem points out that any distributed system cannot satisfy the three attributes at the same time, it is not a binary choice, as the designer of the consensus protocol can weigh up all the three attributes according to the needs of the distributed system. However, as the communication delay is always involved in the distributed system, one always needs to choose between availability and consistency while ensuring a certain degree of partition tolerance. Specifically, in the second case, it is about the value that node 2 returns: a probably outdated value or no value. Returning the possibly outdated value may violate consistency but guarantees availability; yet returning no value deprives the system of availability but guarantees its consistency. Tendermint consensus protocol to be introduced is consistent in this trade-off. In other words, it will lose availability in some cases.
The genius of Satoshi Nakamoto is that with constraints of the CAP theorem, he managed to reach a reliable Byzantine consensus in a distributed network by combining PoW mechanism, Satoshi Nakamoto consensus, and economic incentives with appropriate parameter configuration. Whether Bitcoin's mechanism design solves the Byzantine Generals Problem has remained a dispute among academicians. Garay, Kiayias, and Leonardos analyzed the link between Bitcoin mechanism design and the Byzantine consensus in detail in their paper The Bitcoin Backbone Protocol: Analysis and Applications. In simple terms, the Satoshi Consensus is a probabilistic Byzantine fault-tolerant consensus protocol that depends on such conditions as the network communication environment and the proportion of malicious nodes' hashrate. When the proportion of malicious nodes’ hashrate does not exceed 1/2 in a good network communication environment, the Satoshi Consensus can reliably solve the Byzantine consensus problem in a distributed environment. However, when the environment turns bad, even with the proportion within 1/2, the Satoshi Consensus may still fail to reach a reliable conclusion on the Byzantine consensus problem. It is worth noting that the quality of the network environment is relative to Bitcoin's block interval. The 10-minute block generation interval of the Bitcoin can ensure that the system is in a good network communication environment in most cases, given the fact that the broadcast time of a block in the distributed network is usually just several seconds. In addition, economic incentives can motivate most nodes to actively comply with the agreement. It is thus considered that with the current Bitcoin network parameter configuration and mechanism design, the Bitcoin mechanism design has reliably solved the Byzantine Consensus problem in the current network environment.

## Practical Byzantine Fault Tolerance, PBFT

It is not an easy task to design the Byzantine fault-tolerant consensus protocol in a semi-synchronous network. The first practically usable Byzantine fault-tolerant consensus protocol is the Practical Byzantine Fault Tolerance (PBFT) designed by Castro and Liskov in 1999, the first of its kind with polynomial complexity. For a distributed system with $n$ nodes, the communication complexity is $O(n2$.) Castro and Liskov showed in the paper that by transforming centralized file system into a distributed one using the PBFT protocol, the overwall performance was only slowed down by 3%. In this section we will briefly introduce the PBFT protocol, paving the way for further detailed explanations of the Tendermint protocol and the improvements of the Tendermint protocol.
The PBFT protocol that includes $n=3f+1$ nodes can tolerate up to $f$ Byzantine nodes. In the original paper of PBFT, full connection is required among all the $n$ nodes, that is, any two of the n nodes must be connected. All the nodes of the network jointly maintain the system status through network communication. In the Bitcoin network, a node can participate in or exit the consensus process through hashrate mining at any time, which is managed by the administrator, and the PFBT protocol needs to determine all the participating nodes before the protocol starts. All nodes in the PBFT protocol are divided into two categories, master nodes, and slave nodes. There is only one master node at any time, and all nodes take turns to be the master node. All nodes run in a rotation process called View, in each of which the master node will be reelected. The master node selection algorithm in PBFT is very simple: all nodes become the master node in turn by the index number. In each view, all nodes try to reach a consensus on the system status. It is worth mentioning that in the PBFT protocol, each node has its own digital signature key pair. All sent messages (including request messages from the client) need to be signed to ensure the integrity of the message in the network and the traceability of the message itself. (You can determine who sent a message based on the digital signature).
The following figure shows the basic flow of the PBFT consensus protocol. Assume that the current view’s master node is node 0. Client C initiates a request to the master node 0. After the master node receives the request, it broadcasts the request to all slave nodes that process the request of client C and return the result to the client. After the client receives f+1 identical results from different nodes (based on the signature value), the result can be taken as the final result of the entire operation. Since the system can have at most f Byzantine nodes, at least one of the f+1 results received by the client comes from an honest node, and the security of the consensus protocol guarantees that all honest nodes will reach consensus on the same status. So, the feedback from 1 honest node is enough to confirm that the corresponding request has been processed by the system.

https://preview.redd.it/sz8so5ly7m851.png?width=1400&format=png&auto=webp&s=d472810e76bbc202e91a25ef29a51e109a576554
For the status synchronization of all honest nodes, the PBFT protocol has two constraints on each node: on one hand, all nodes must start from the same status, and on the other, the status transition of all nodes must be definite, that is, given the same status and request, the results after the operation must be the same. Under these two constraints, as long as the entire system agrees on the processing order of all transactions, the status of all honest nodes will be consistent. This is also the main purpose of the PBFT protocol: to reach a consensus on the order of transactions between all nodes, thereby ensuring the security of the entire distributed system. In terms of availability, the PBFT consensus protocol relies on a timeout mechanism to find anomalies in the consensus process and start the View Change protocol in time to try to reach a consensus again.
The figure above shows a simplified workflow of the PBFT protocol. Where C is the client, 0, 1, 2, and 3 represent 4 nodes respectively. Specifically, 0 is the master node of the current view, 1, 2, 3 are slave nodes, and node 3 is faulty. Under normal circumstances, the PBFT consensus protocol reaches consensus on the order of transactions between nodes through a three-phase protocol. These three phases are respectively: Pre-Prepare, Prepare, and Commit:
• The master node of the pre-preparation node is responsible for assigning the sequence number to the received client request, and broadcasting the message to the slave node. The message contains the hash value of the client request d, the sequence number of the current viewv, the sequence number n assigned by the master node to the request, and the signature information of the master nodesig. The scheme design of the PBFT protocol separates the request transmission from the request sequencing process, and the request transmission is not to be discussed here. The slave node that receives the message accepts the message after confirming the message is legitimate and enter preparation phase. The message in this step checks the basic signature, hash value, current view, and, most importantly, whether the master node has given the same sequence number to other request from the client in the current view.
• In preparation, the slave node broadcasts the message to all nodes (including itself), indicating that it assigns the sequence number n to the client request with the hash value d under the current view v, with its signaturesig as proof. The node receiving the message will check the correctness of the signature, the matching of the view sequence number, etc., and accept the legitimate message. When the PRE-PREPARE message about a client request (from the main node) received by a node matches with the PREPARE from 2f slave nodes, the system has agreed on the sequence number requested by the client in the current view. This means that 2f+1 nodes in the current view agree with the request sequence number. Since it contains information from at most fmalicious nodes, there are a total of f+1 honest nodes that have agreed with the allocation of the request sequence number. With f malicious nodes, there are a total of 2f+1 honest nodes, so f+1represents the majority of the honest nodes, which is the consensus of the majority mentioned before.
• After the node (including the master node and the slave node) receives a PRE-PREPARE message requested by the client and 2f PREPARE messages, the message is broadcast across the network and enters the submission phase. This message is used to indicate that the node has observed that the whole network has reached a consensus on the sequence number allocation of the request message from the client. When the node receives 2f+1 COMMIT messages, there are at least f+1 honest nodes, that is, most of the honest nodes have observed that the entire network has reached consensus on the arrangement of sequence numbers of the request message from the client. The node can process the client request and return the execution result to the client at this moment.
Roughly speaking, in the pre-preparation phase, the master node assigns a sequence number to all new client requests. During preparation, all nodes reach consensus on the client request sequence number in this view, while in submission the consistency of the request sequence number of the client in different views is to be guaranteed. In addition, the design of the PBFT protocol itself does not require the request message to be submitted by the assigned sequence number, but out of order. That can improve the efficiency of the implementation of the consensus protocol. Yet, the messages are still processed by the sequence number assigned by the consensus protocol for the consistency of the distributed system.
In the three-phase protocol execution of the PBFT protocol, in addition to maintaining the status information of the distributed system, the node itself also needs to log all kinds of consensus information it receives. The gradual accumulation of logs will consume considerable system resources. Therefore, the PBFT protocol additionally defines checkpoints to help the node deal with garbage collection. You can set a checkpoint every 100 or 1000 sequence numbers according to the request sequence number. After the client request at the checkpoint is executed, the node broadcasts messages throughout the network, indicating that after the node executes the client request with sequence number n, the hash value of the system status is d, and it is vouched by its own signature sig. After 2f+1 matching CHECKPOINT messages (one of which can come from the node itself) are received, most of the honest nodes in the entire network have reached a consensus on the system status after the execution of the client request with the sequence numbern, and then you can clear all relevant log records of client requests with the sequence number less than n. The node needs to save these2f+1 CHECKPOINTmessages as proof of the legitimate status at this moment, and the corresponding checkpoint is called a stable checkpoint.
The three-phase protocol of the PBFT protocol can ensure the consistency of the processing order of the client request, and the checkpoint mechanism is set to help nodes perform garbage collection and further ensures the status consistency of the distributed system, both of which can guarantee the security of the distributed system aforementioned. How is the availability of the distributed system guaranteed? In the semi-synchronous network model, a timeout mechanism is usually introduced, which is related to delays in the network environment. It is assumed that the network delay has a known upper bound after GST. In such condition, an initial value is usually set according to the network condition of the system deployed. In case of a timeout event, besides the corresponding processing flow triggered, additional mechanisms will be activated to readjust the waiting time. For example, an algorithm like TCP's exponential back off can be adopted to adjust the waiting time after a timeout event.
To ensure the availability of the system in the PBFT protocol, a timeout mechanism is also introduced. In addition, due to the potential the Byzantine failure in the master node itself, the PBFT protocol also needs to ensure the security and availability of the system in this case. When the Byzantine failure occurs in the master node, for example, when the slave node does not receive the PRE-PREPARE message or the PRE-PREPARE message sent by the master node from the master node within the time window and is thus determined to be illegitimate, the slave node can broadcast to the entire network, indicating that the node requests to switch to the new view with sequence number v+1. n indicates the request sequence number corresponding to the latest stable checkpoint local to the node, and C is to prove the stable checkpoint 2f+1 legitimate CHECKPOINT messages as aforementioned. After the latest stable checkpoint and before initiating the VIEWCHANGE message, the system may have reached a consensus on the sequence numbers of some request messages in the previous view. To ensure the consistency of these request sequence numbers to be switched in the view, the VIEWCHANGE message needs to carry this kind of the information to the new view, which is also the meaning of the P field in the message. P contains all the client request messages collected at the node with a request sequence number greater than n and the proof that a consensus has been reached on the sequence number in the node: the legitimate PRE-PREPARE message of the request and 2f matching PREPARE messages. When the master node in view v+1 collects 2f+1 VIEWCHANGE messages, it can broadcast the NEW-VIEW message and take the entire system into a new view. For the security of the system in combination with the three-phase protocol of the PBFT protocol, the construction rules of the NEW-VIEW information are designed in a quite complicated way. You can refer to the original paper of PBFT for more details.

VIEWCHANGE contains a lot of information. For example, C contains 2f+1 signature information, P contains several signature sets, and each set has 2f+1 signature. At least 2f+1 nodes need to send a VIEWCHANGE message before prompting the system to enter the next new view, and that means, in addition to the complex logic of constructing the information of VIEWCHANGE and NEW-VIEW, the communication complexity of the view conversion protocol is $O(n2$.) Such complexity also limits the PBFT protocol to support only a few nodes, and when there are 100 nodes, it is usually too complex to practically deploy PBFT. It is worth noting that in some materials the communication complexity of the PBFT protocol is inappropriately attributed to the full connection between n nodes. By changing the fully connected network topology to the P2P network topology based on distributed hash tables commonly used in blockchain projects, high communication complexity caused by full connection can be conveniently solved, yet still, it is difficult to improve the communication complexity during the view conversion process. In recent years, researchers have proposed to reduce the amount of communication in this step by adopting aggregate signature scheme. With this technology, 2f+1 signature information can be compressed into one, thereby reducing the communication volume during view change.

##### Job scams. PayPal/Bitcoins scams?

Back in March I signed up for indeed, careerbuilder and Glassdoor.
Due to the covid 19 company’s where hiring with zoom/phone calls interview (I actually got a job that way) but there have been so many scams it’s just ridiculous. Here is one that I actually work for some days because I found it interesting but look at this info and you tell me what your judgement tells you.
Note: I am posting this as a text because I google search the emails initials emails and there was not result out there for this company so I wanted to leave this out others’ search’s
First email
BRACK Support
Good Day ! We have RECEIVED YOUR APPLICATION for the work position:
My name is J—— M—— , and I will be your personal consultant. I am a specialist of the BRACK.CH Company. First, I would like you to study the details below and make a decision about our partnership. I am ready to answer all your questions if you have any. Please learn each part of the position carefully:

BRACK.CH is a Swiss trading company founded by Roland Brack in 1994. We started using the Internet and e-Commerce at an early stage. Today, our company generates most of its sales through our online store. The number of our users exceeds 15 million. Every day there are more than 1 million transactions made. Currently we develop the North American market. The US economy is the most powerful economy worldwide and their banking and payment systems work comfortably and stably. These factors provide a basis for profitable cooperation of American and European customers. The problem we need to resolve is the language barrier. Every day we have correspondence with our employees and customers from the United States. English is not our native language. Furthermore, American English and European English have many differences that can bring some inaccuracy in our communication. Our correspondence has a business character and is often associated with finances. Any inaccuracies may cause misunderstandings. We hope that you are a responsible person who can proofread our business correspondence.

# JOB DETAILS:

• Every work day (Monday - Friday) you will receive an email from us containing texts for editing.
• You will have only 24 hours to complete them. The work will take about 30 minutes.
• You can do this work at any time and in any text format you prefer.
• After you have finished editing the texts - send your corrections back to us. Attention! Its very important that you white-list our e-mail address, to insure that you receive our correspondence in a timely manner. Please check your emails from us every day and check all folders, since we send emails every day.

• You will be paid $5 for 1Kb of text (1Kb = 1024 symbols). • Every working day you will receive approximately 8-10 kilobytes of texts (about 50 dollars of daily income). • Every day we will count your balance and send you reports. • At the initial stage of cooperation, we will pay you every two weeks. The 1st month is a test period to check your responsibility and communication skills, after this we may sign an agreement with you. We will list everything in it such as taxes, expenses, fees, interests and everything else necessary to have a partnership with you. • After signing the agreement, we will be able to pay for your work daily. It will depend on your desire. Career growth is possible. • We use PAYPAL for payments. It’s very safe. You do not need to provide us any of your personal information. You should have a PayPal account (verified). We will send you all payments via your PayPal account. ATTENTION! Now you have read and understand the job details. Please let us know if you are interested. Also, please provide us your PAYPAL email. WAITING FOR YOUR RESPONSE. ----next email ------ BRACK Support Mon, May 25, 11:22 AM (13 days ago) to me We have RECEIVED YOUR APPLICATION for the work position: My name is Joseph Marshall, and I will be your personal consultant. I am a specialist of the BRACK.CH Company. First, I would like you to study the details below and make a decision about our partnership. I am ready to answer all your questions if you have any. Please learn each part of the position carefully: # ABOUT OUR COMPANY: BRACK.CH is a Swiss trading company founded by Roland Brack in 1994. We started using the Internet and e-Commerce at an early stage. Today, our company generates most of its sales through our online store. The number of our users exceeds 15 million. Every day there are more than 1 million transactions made. Currently we develop the North American market. The US economy is the most powerful economy worldwide and their banking and payment systems work comfortably and stably. These factors provide a basis for profitable cooperation of American and European customers. The problem we need to resolve is the language barrier. Every day we have correspondence with our employees and customers from the United States. English is not our native language. Furthermore, American English and European English have many differences that can bring some inaccuracy in our communication. Our correspondence has a business character and is often associated with finances. Any inaccuracies may cause misunderstandings. We hope that you are a responsible person who can proofread our business correspondence. # JOB DETAILS: • Every work day (Monday - Friday) you will receive an email from us containing texts for editing. • You will have only 24 hours to complete them. The work will take about 30 minutes. • You can do this work at any time and in any text format you prefer. • After you have finished editing the texts - send your corrections back to us. Attention! Its very important that you white-list our e-mail address, to insure that you receive our correspondence in a timely manner. Please check your emails from us every day and check all folders, since we send emails every day. # SALARY: • You will be paid$5 for 1Kb of text (1Kb = 1024 symbols).
• Every working day you will receive approximately 8-10 kilobytes of texts (about 50 dollars of daily income).
• Every day we will count your balance and send you reports.
• At the initial stage of cooperation, we will pay you every two weeks. The 1st month is a test period to check your responsibility and communication skills, after this we may sign an agreement with you. We will list everything in it such as taxes, expenses, fees, interests and everything else necessary to have a partnership with you.
• After signing the agreement, we will be able to pay for your work daily. It will depend on your desire. Career growth is possible.
• We use PAYPAL for payments. It’s very safe. You do not need to provide us any of your personal information. You should have a PayPal account (verified). We will send you all payments via your PayPal account.
ATTENTION! Now you have read and understand the job details. Please let us know if you are interested. Also, please provide us your PAYPAL email.
4.6(D_10043121) Letter “Job Offer” Dear Sir / Madam Thank you for your interest in our company! Our company is engaged in the purchase and resale of goods in foreign auctions. Including eBay. We have been working for several years in this business and develop further. Since we have moved to a new stage of development, we have more customers, more transactions, the quality of transactions is improved, we gained experience and have made many friends. Now we have vacant positions - representative. Who lives in a country in which we sell a product and he takes for us the payment on Paypal. We cannot accept the payment on Paypal by ourselves as the limit for sending money to Portugal via Paypal - $350 a month. But there is always a way out of these situations, because there are a lot of good people on earth which are willing to help, and of course we will always pay for all the help we need in our business. So we want to offer you to become our representative, especially considering the fact that time that you will spend no more than 1 hour a day and not every day, and will earn$ 3,000 or more. So imagine - \$ 1,500 per month is a fixed salary. In addition to the salary is 5% from each transaction. You will collect a good amount during the month. To become our representative, you need to send us the answer with request to review your application and send you the details, description, answers to your questions, the necessary data required from you in order to start the work. Of course, we will pay you at once! You will see it from the first transaction. Try to consider our proposal carefully and without shelving test yourself at this work. It’s all up to you, the more effort – the more you can earn. We guarantee a safe work! Thank you,