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Let’s move on to cash. We’ve compared cash and credit in the past, and pointed out that cash systems need to be “bootstrapped,” but the advantage is that it eliminates the risk of a buyer who is in default on their credit. Cash also has two benefits. First, it provides greater privacy. Since your credit card was issued under your personal name, your lender can monitor your spending. However, when you pay with money, your bank does not enter the picture, and the third party isn’t required to know who you are. Cash can also facilitate transactions that are not online, and you don’t need to call home to another person to obtain the transaction’s approval. Perhaps later, they’ll make a trip to a third party like a bank for depositing funds, though it’s significantly less of a headache. List of Investors email id list

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Bitcoin does not quite have these two qualities, but is near enough that it can be effective. Bitcoin isn’t completely anonymous at the same extent that cash is. It is not necessary to reveal your personal identity to make payments in Bitcoin however it is likely that transactions will be connected to your public record of transactions using clever algorithms, and further linked to your personal identity If you’re not cautious. We’ll go over the tangled yet fascinating details of Bitcoin anonymity in Chapter 6. Investors Email lists

Bitcoin isn’t able to function in a totally offline fashion neither. It’s a good thing that it doesn’t need an intermediary server, instead relieving on a peer-to-peer system that is as robust it is it is the Internet does. In Chapter 3 we’ll take a look at methods such as “green addresses” and micropayments that permit us to conduct offline payments in certain scenarios or in certain scenarios. Investors email Database,

The first concepts of applying cryptography to money were conceived by David Chaum in 1983. Let’s consider this in terms of the analogy of a physical. Let’s suppose I begin giving out small pieces of paper with the words: “The bearer of this note may redeem it for one dollar by presenting it to me” with my signature. If they trust me to respect my word and believe my signature as unfalsifiable They can distribute these pieces of paper as banknotes. Indeed, banknotes began as note-like promissory bonds issued by banks. It was only during the latter half of time that governments took the initiative to regulate the supply of money and legally mandate banks to pay back notes.

I could accomplish the same issue electronically using digital signatures. However, this isn’t without the “double spending” problem -when you receive the data that is the virtual currency it is possible to make at least two (or additional) replicas, and then pass them across to various individuals. To stay to our analogy, let’s take it a step further and assume that the people create perfect copies, and we are unable to distinguish different copies apart from original. Do we have a solution to the problem of the problem of double spending in our world?  Investors mailing lists

This is a solution that could be a good one One solution is to incorporate unique serial numbers into every note I distribute. If you get an email from someone else, you look up my signature. You can also contact me via the phone to inquire if the note that has the serial number has been used. Most likely, I’ll tell you no, which is why you take the note. I’ll note the serial number that was used in my ledger. And when you attempt to use the note, it won’t succeed because the recipient will contact me and I’ll inform them that the note is already used up. What you’ll have to do is regularly bring to me all notes you’ve received and I’ll give you the same number of new notes, with new serial numbers. Database of Investors email leads

This is a good idea. It’s not easy in real life however, it’s easy to do digitally. I’ve created a server to keep track of the signing and recording of serial number. The only problem is it’s not really money anymore, since it’s not private When I write an email to you, I’ll note the serial number with your name and make the same record when another person later redeems it. So, I’m able to keep an eye on all the locations that you’re spending your money.

This is where the genius of Chaum is a key element. He was able to ensure the system’s anonymity and stop double-spending by inventing an electronic version of the following method that I use when I mail you a new note You choose your serial number. Write it down on the paper, and then you cover it with a paper so that I’m not able to see the serial number. Then , you sign it, however, I’m unable to read that serial number. This is referred to as an “blind signature” in cryptography. It’s in your best desire to choose an extended random serial number to make sure that it will probably be unique. There’s no need to worry about choosing the same serial number that has already chosen You could make yourself a victim in this manner and then end up with an account that isn’t able to be used. Investors email id list

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It was the first major digital cash idea. It is working however it needs an administrator from an authority central to the system like an institution, and for everyone to believe in that. Furthermore, every transaction requires the presence of this server to pass through. If the server is down temporarily, payments slow to a stop. In the following year around 1988 Chaum along alongside another two cryptographers Fiat and Naor suggested offline electronic cash. At first glance, this may appear impossible If you use the exact digital coin or note in two different places How can they stop it unless they’re linked to the exact same payment system or central authority? Investors Mailing Database

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The smart approach is to not worry about preventing double-spending , and instead focus on detecting it in the aftermath, after the merchant reconnects to the bank server. In the end, that’s why you are able to utilize your credit card while in an airplane even if there’s no internet connection on the ground. The transaction processing takes place after the airline can reconnect to its network. If your card is rejected and you’re unable to pay the airline (or you banking institution) money. If you consider it, a good portion of traditional finance is built around the concept of detecting an error or loss then attempting to retrieve the funds or penalize the culprit. If you make an individual a personal check, they aren’t guaranteed that the cash is in your bank account, but they may pursue you in the event that your check is returned. It is possible that if an electronic cash system for offline use was adopted widely and accepted by the law, the system would be able to accept the crime of double spending.  Investors Email lists

Chaum, Fiat, and Naor’s concept of finding double-spenders was a complex cryptographic dance. In the grand scheme of things the result was that every digital currency you receive encodes your personal information however, in such it is so that nobody other than you, and not even the bank, is able to decode it. Every time you make a purchase with your money, the person who received it will ask for you to decode an undetermined part of the encryption and will keep a record of the transaction. The decoding won’t be enough to to verify your identity. However, if you twice spend money and both of the recipients visit the bank to cash in their notes. And after that the bank will be able to put the two pieces of information to determine your identity in full and with a remarkably high likelihood. Investors email listing

You may be wondering if anyone could accuse you of being double spender within this method. Imagine you spent a dollar with me, but I then turned around and attempted to double-spend it (without paying it back to the bank or obtaining an additional coin that has my name encoded). It won’t work because the new customer will require me to decode an unidentified subset. This most likely won’t be exactly the same as the one that you decoded on my behalf, which means I won’t be in a position to satisfy the decoding request.

Through the years, a variety of cryptographers have examined the structure and modified it in various ways. The Chaum-Fiat Naor scheme is when a coin’s value is $100 and you want to purchase something for less than $75 you can’t divide that coin into two pieces, namely $75 and $25. The only option is to return at the cashier, deposit in the $100 coin and request a $75 coin as well as a $25 one. The paper from Okamoto and Ohta makes use of “Merkle trees” to create an system that allows you to divide your coins. Merkle trees will be present in Bitcoin too and we’ll get to these in the first chapter. The Chaum-Fiat-Naor scheme has plenty of room to improve effectiveness. In particular, the application of something called zero-knowledge proofs to this scheme (most notably by Brands; and Camenisch, Hohenberger, and Lysyanskaya) was very fruitful–zero-knowledge proofs have also been applied to Bitcoin as we will see in Chapter 6.  Investors lists

But let’s go back to Chaum who used his ideas to commercialize the ideas. He founded an organization in 1989 named DigiCash possibly the first company to attempt to address the issue of online payment. DigiCash had a advantage over other companies such as FirstVirtual and CyberCash which we have mentioned. The actual money in Digicash’s system was known as Ecash and they also had another system known as cyberbucks. There were banks that used it — some within the US and at the very least the one located in Finland. It was the 90s and long before Bitcoin was introduced, which could be a surprise to certain Bitcoin fans who see banks as anti-tech, uninnovative beasts. List of Investors email listing

Ecash is built on the Chaum protocol. Clients are anonymous, which means that banks cannot track where they’re spending their funds. However, merchants who use electronic cash aren’t. They must return the money immediately after they receive themso that the bank can know what they’re earning and at what times and so on.

When you’re ready to conduct an exchange, say like in this case that you’d like to donate money to the privacy group EPIC, a non-profit organization. EPIC You’ll click the donation link which will take your to Digicash website. This will then create an reverse web connection towards your personal computer. Your computer would have be able to accept connections and function as server. It must have an IP address of your own and your Internet service provider would need allowed incoming connections. If the connection is successful and the software will be launched on your system and you’d be able confirm the transaction and transfer the cash. buy Investors email database

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Chaum was the inventor of several patents related to Digicash technology. In particular, the method of blind-signature that it employed. It was a controversial choice, and also stopped other developers from developing ecash systems which employed the same protocols. However, a few cryptographers who frequented the Cypherpunks mailing list sought to find a different option. Cyperpunks was the forerunner of the list that Satoshi Nakamoto would later reveal Bitcoin worldwide at large, and it’s no accidental. We’ll explore the cypherpunk revolution as well as the genesis of Bitcoin in Chapter 7. buy Investors database online

The cryptographers from the Cypherpunk community developed an ecash-like version known as MagicMoney. It was not in compliance with patents, however it was advertised as being a test-bed for usage. It was an enjoyable piece of software to experiment with. The interface was entirely written in text. Transactions could be sent via email. It’s as simple as copying and paste the transaction into your email, and then send it to a different user. Most likely, you’ll employ the complete encryption of your email software like PGP to safeguard the transaction while it’s in the process of.

There’s also a plan known as Lucre from Ben Laurie with contributions from numerous other contributors. Lucre tries to replace the blind-signature scheme in ecash with a non-patent-encumbered alternative, with the rest of the system largely the same. Investors lists

Another idea, proposed from Ian Goldberg, tries to solve the issue of being unable to split your coins so that you can change them. The concept was that the retailer could give you back coins in the event that they had coins. This would mean that you could overpay for the product if you don’t have the exact change. Then you’d be able to get some coins back. However, it’s important to note that this introduces an issue of anonymity. We’ve already seen that with ecash, the sender is not able to be identified, but merchants are. If a merchant transfers the cash, legally they are the sender, therefore they’re not anonymous. However, you, as the person who is required to return the cash to the bank aren’t anonymous. There’s no way to implement this system without compromising the privacy of those who want to purchase products. Therefore, Goldberg proposed an idea that included various kinds of coins that could let these transactions take place and allow you to receive the change back, but ensure your privacy. Investors email listing

The question is, why did DigiCash failed? The biggest issue with DigiCash was that it was difficult to convince banks and merchants to accept it. There weren’t many stores who accepted e-cash, the customers did not want it. It also didn’t allow user-to-user transactions or at least in a way that was very effective. It was primarily focused around the transaction between merchants and users. If merchants weren’t involved and there wasn’t any other way to increase the interest rate in the system. At the end of all of the proceedings, DigiCash was a loser and credit card firms took the win.

In addition, Bitcoin permits user-to-merchant as well as user-to-user transactions. In reality it doesn’t even have a concept of merchant which is separate from the concept of the user. The ease of transactions between users is likely to have contributed to the success of Bitcoin. There was something you could do with your Bitcoins from the beginning. You could transfer the money to other users, as the community attempted to build acceptance for Bitcoin and to convince merchants to accept it.

In the later years of the company, DigiCash also experimented with tamper-resistant hardware to try to preventdouble-spending rather than just detecting it. In this method it was a small hardware device that was commonly known as a wallet, or a card of some kind. The device kept an eye on your balance and it would reduce when you made purchases and increase when you loaded your card with more cash. The idea behind the system is there must be no method to physically or electronically go into it and alter the counter. Therefore, if the counter is hit zero, the card ceases to be capable of spending cash until it’s reloaded. List of Investors email database

There were numerous other companies with electronic cash systems built on hardware that was tamper-proof. DigiCash later collaborated with a firm called CAFE that was located in Europe. Another company that was formed around this concept was called Mondex and was later bought by Mastercard. Visa also had its own version of the VisaCash brand. VisaCash. Investors Email lists

There’s a smartcard as well as a wallet that you can fill either or both with money. If you want to swap users-to-user cash, the person giving the money will first insert their wallet into the card and then transfer the money from the card to the wallet. The receiver would then put their wallet with the card then move the money onto the other card. This was a method of transfer digital cash, and it was completely anonymous. buy Investors email database

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Mondex tried out the technology they developed in number of communities. One of the communities was one of the cities close to where I was born: Guelph, Ontario. It’s likely that you’ve already realized it wasn’t a huge success. One of the biggest issues that comes with Mondex card is the fact that they’re akin to cash. If you lose them or become stolen, your money will be gone. In the event of some kind of issue in the card, and the reader can’t detect it then there’s no way to determine if the card was in balance or not. In such situations, Mondex would typically eat the cost. They’d presume that it’s loaded , and refund the cardholder for the lost cash. Naturally, this can cost a business a lot of dollars. buy Investors database online

The wallet itself was slow and heavy. It was quicker to pay by credit card or by cash. The retailers were not happy with having multiple payment options; they only wanted one terminal that could accept credit card. All of these factors combined brought Mondex into.

But, they were smart cards. This means that they are equipped with microcontrollers and that the technology has proven to be effective. In several countries and even Canada in which I reside each credit card and debit card is now equipped with technology for smart cards. It’s utilized to fulfill a different function, however. It’s not intended to prevent double-spending. The issue does not arise because it’s not an ATM-based technology. The bank, not your card, is in charge of your account balance or credit. The chip is instead utilized for authentication, which is, to prove you have the correct PIN associated to your account. However, Mondex had been using it long before it was widely adopted in the financial industry.

Minting Money out of Thin Air

The DigiCash system in the DigiCash system, if you’ve got an electronic cash object worth $100, what is it really worth $100? It’s simple for you to get the ecash equivalent to $100, you’d have withdraw $100 from your account at the bank and transfer it to the institution which issued the digital cash. However, there were a myriad of different ideas on how to go about this and how different firms did it differently. A more unlikely scenario could be that the government of one particular country actually permitted companies to mint digital currency and create new money from the air? This was the concept behind NetCash however it was never able to get past the idea stage. Another system, utilized by e-Gold was to keep an amount of gold in vaults and then give digital cash only to the amount of gold. Another company , called Digigold was not completely supported with gold but did have limited reserves. List of Investors email database

All of these theories have the effect of tying an amount of currency to the dollar, or a commodity. If the value of the dollar fluctuates either way then what value will your online cash possessions will also change with it. An alternative is to permit digital money to become its own currency that is issued and valued independent of any other currency.

To make a floating digital currency that’s likely to appreciate in value, you have to be able to find something rare because of design. Indeed it’s also the reason why gold and diamonds are utilized as a backer for currency. In the world of digital currencies one method to attain scarcity is to create the system in a way that making money is dependent on solving a mathematical issue (or “puzzle”) that is difficult to crack. This is exactly what happens in Bitcoin “mining”, which we’ll explore within Chapter 5. Investors lists

The concept of that the solutions to problems with computation may be digital, tangible objects that hold some value quite old. It was initially proposed by two cryptographers Dwork as well as Naor as a possible solution to the problem of spam email in the year 1992. What if, each when you sent an email the computer was required to solve a puzzle that could take only a few minutes to solve? To ensure this is the case the email program of the recipient will simply disregard your email that you didn’t include the answer to the computational puzzle. For the average person this wouldn’t be too an issue sending emails, since you’re not sending out emails too often. However, if you’re a spammer, then you’re trying to send millions or even thousands of emails at once and figuring out those computational problems could be a challenge. The idea was developed independently through Adam Back in 1997 in the form of a concept called Hashcash. Investors email database

These puzzles that are computational must possess specific characteristics to function as a good anti-spam tool. It should first be difficult for spammers to solve a particular puzzle and then attach the answer to every email he forwards. To guarantee this it is necessary that the puzzle be unique to the email in that it should be based on the sender’s and the receiver’s as well as the content in the message, as well as the time of when it is delivered. In addition, the recipient will be able easily verify the puzzle’s solution without needing to repeat the procedure in solving it. Thirdly, each puzzle must be completely independent of others in the sense the fact that solving one problem will increase the time required to solve every other puzzle. Furthermore, as hardware advances over time, and solving a particular computational puzzle becomes faster and more affordable, users are expected to be able to alter the difficulty of puzzle solutions they accept. This can be accomplished through the use of cryptographic hash functions to create puzzles and we’ll look into this in Chapter 1.

Bitcoin employs the same algorithmic puzzle that was used in Hashcash however, with some slight advancements. Bitcoin is better than Hashcash does however it is true that it requires a book to describe Bitcoin! This is only because Hashcash creator Adam Back has said, “Bitcoin is Hashcash extended with inflation control.” I think that’s a little too broad. It’s similar to saying that “a Tesla is just a battery on wheels.” buy Investors email database

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Like any great idea of cryptography there exist a variety of kinds of computational puzzles which seek to produce somewhat different results. One of the ideas is directly from Rivest and Shamir who are who are the R as well as an S of the RSA cryptosystem. It is worth noting that in Hashcash the cost you pay to solve a variety of puzzles is the sum of your individual costs, as per the design. However, this is not the same as the cost structure of the government to issue money. When you think about the it is to prevent counterfeiting in a currency that is paper has to be, there’s an enormous initial expense to purchase all the equipment needed, design security features, and other things like that. After they’ve accomplished all of that, their expenses decrease and it doesn’t really matter if they print just one or a hundred. That’s why minting paper money is an enormous fixed cost, but a the marginal cost is low. Rivest and Shamir set out to create computational puzzles that resemble the properties of paper money, so that minting the initial coin is extremely computationally difficult while minting later coins is much less expensive. Their solution also employed hash functions, however in a different fashion. We won’t discuss the specifics of their approach however the issue they attempted to solve is fascinating at a higher scale. buy Investors database online List of Investors lists

Why didn’t Hashcash not get the attention of its primary goal of preventing spam? Perhaps spam was not enough of a problem to address. Most people view spam as an annoying nuisance, but it’s isn’t something they would like to devote their time trying to combat. Today, we have spam filters that are quite effective at blocking spam from our inboxes. It’s also possible that Hashcash would not have stopped spammers. Particularly, the majority of spammers are now sending their emails through botnets, massive groupings of other computer systems that they gain control of with malware. They could also make use of these computers to mine Hashcash. However, the concept of making use of computational puzzles to restrict the access of resources something that’s being discussed. It’s evident in some suggestions to replace network protocols for instance MinimaLT. Investors Contact Email

Recording Everything in a Ledger

Another important aspect in Bitcoin includes the block chain, which is an account in which every Bitcoin transactions are safely recorded. The concepts that underlie the blockchain are rather old, and can be traced back to a paper written by Haber as well as Stornetta in the year 1991. Their idea was to secure timestamping digital documents, and not a digital money scheme. The purpose of time stamping is to provide an approximate time frame of the date that a document was created. Additionally, it accurately will reveal the chronological order of these documents. If one was created prior to the other, the time stamps will show the date of creation. Security properties require that the document’s time stamp can’t be altered following the event. List of Investors lists

In the Haber and Stornetta scheme it’s possible to use a time stamping service that allows clients to submit documents to a timestamp. Once the servers receive the document, it signs the document with the current date and time in addition, an identifier or link to the document that was previously received, and issue an “certificate” with this information. The pointer is can be a type-specific pointer that is linked to a specific part of information instead of an address. This means that should the data is changed, then the pointed will automatically becomes invalid. In Chapter 1, we’ll explore how to create these pointers by using hash functions.  Investors Email Leads

This means that every certificate of a document guarantees the integrity of the information of the document before it. In reality, you could apply this logic in a recursive manner: each certificate basically changes the history of all documents and certificates until the point at which it is issued. In the event that every participant on the system maintains a record of at least a handful of certificates that are their own as well as those of the preceding and subsequent documents then the system are able to ensure that the past is not altered in the future. Particularly the chronological order of documents is maintained.

In a subsequent paper, we proposed an efficiency enhancement that is: instead of linking documents in isolation they could be grouped into blocks, and then link them together as chains. Inside each block documents would also be linked however, in a tree-like structure instead of in a linear fashion. This reduces the amount of testing required to confirm that a specific document was created at a certain time in the timeline that the software. List of Investors lists

The data structure that is created forms the foundation that forms the block chain of Bitcoin as we’ll discover in Chapter 3. Bitcoin enhances it in through a subtle but significant way by using a Hashcash-like protocol employed to slow the rate at which adding new blocks in the chain. This change has significant positive effects on Bitcoin’s security system. There is no longer a requirement of trusted servers, instead the events recorded are recorded through a set of non-trusted nodes referred to “miners”. Every miner records blocks, and does not have to rely on normal users to keep track of it. Anyone can be mining by solving mathematical problems to generate blocks. Bitcoin also eliminates signatures and relies on hash pointsers to protect that the structure of data is secure. In addition, the actual timestamps don’t have much significance in Bitcoin as the purpose for the software is simply to document the sequence of the transactions, in a secure method. Actually, Bitcoin blocks aren’t created according to a predetermined timeframe. The system makes sure that new blocks are generated every 10 minutes, on average however there is a significant variations in the duration between each block. email marketing database List of Investors

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In the simplest sense, Bitcoin combines the idea of using mathematical puzzles to regulate the making and development of currencies along with the concept of secure timestamping to create a ledger of transactions, and to prevent duplicate spending. There were earlier, less sophisticated ideas which combined the two concepts. The first was”b-money,” and was developed invented by Wei Dai in 1998. With b-money, anyone is able to create money by using a hashcash-like system. There’s a network of peer-to peer similar to that of Bitcoin. Each node keeps a ledger but this isn’t a global ledger, as it is in Bitcoin. Bitcoin block chain. Every node is able to keep its own version that shows the balance it believes everyone’s is. List of Investors email database providers of Investors Email List

Another similar proposal, made by Nick Szabo, is called Bitgold. Szabo states that he had the concept for Bitgold at the time of 1998 however he didn’t even get around to writing about it until the year 2005. The reason I bring this up is due to a minor conspiracy theory that was popularized through Nathaniel Popper, a New York Times reporter who wrote an excellent book on the background of Bitcoin. Popper mentions that the timestamps of blog posts were modified following the time Satoshi published the Bitcoin whitepaper, so that the Bitgold proposition appears as if it was written one month after Bitcoin was launched. Popper is of the opinion, as are many others that Szabo might be Satoshi and points to the change in timestamps as proof that Szabo/Satoshi is trying to conceal what he knew about Bitcoin. created Bitgold before he was aware of Bitcoin.

The issue in this theory is, if one actually perused the content of blog posts, Szabo is very clear of having thought about this in 1998. He also does not try to alter the dates. Therefore, a more plausible theory is that Szabo simply moved the blog post up to at the very top of his website when Bitcoin became popular with similar ideas to make sure the public was aware of his earlier suggestion. List of Investors lists


We can then think, “What did Satoshi know about the history of ecash?” To grasp this more clearly, we could begin by looking through what the author cites in his white paper and also the references on the earlier editions of the Bitcoin website. In his white paper, it cites a few documents on cryptography basics and probability theory. He also references the work in time-stamping that we have seen earlier and it’s only plausible to believe that he designed the structure of the chain being based on such sources because the similarities are obvious. He also mentions the Hashcash idea, which’s computational puzzle is quite similar to the one utilized in Bitcoin. There’s also the b-money reference. Then, on the website he made the references of Bitgold and also to an idea by Hal Finney for reusing computational puzzles. List of Investors lists

If we examine the emails exchanges made public by those who had correspondence with Satoshi Nakamoto during the beginning of the internet, we can see that the b-money idea was added later, as a result of the suggestions by Adam Back. Satoshi then sent an email to Wei Dai who created b-money and it appears that Dai was the person who advised him of Bitgold. This suggests that these ideas weren’t sources of inspiration for the original design. The designer later remained in contact in correspondence with Hal Finney, and that’s an excellent explanation of the reason he references Finney’s work on his website. email marketing database List of Investors

On the basis of this information, it is plausible that during the time of the creation of Bitcoin, Hashcash and time-stamping were the only items from the early days of ecash that Satoshi was aware of or believed were significant. Once he became aware of B-money and Bitgold However it appears that he recognized their importance. In the mid-2010 timeframe the Wikipedia article about Bitcoin was flagged as unworthy of deletion by Wikipedia’s editors based on their opinion that it was not interesting enough. The article was subject to debate between Satoshi and other people about the best way to write the article to ensure that Wikipedia would be able to accept the article. To this end, Satoshi suggested this description of Bitcoin: “Bitcoin is an implementation of Wei Dai’s b-money proposal on Cypherpunks in 1998 and Nick Szabo’s Bitgold proposal.” Thus, Satoshi at this point, was the positioning of Bitcoin as an expansion of these ideas or as an implementation of the two previous methods as a clear explanation of the way it works.

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But, what’s the deal with all the other things — the Chaumian E-Cash schemes as well as the credit card plans we examined? Did Satoshi be aware of any of that history while he was designing Bitcoin? It’s not clear. The man didn’t provide any evidence of having any knowledge about this background, but it’s possible that he didn’t refer to it since it wasn’t pertinent to Bitcoin. Bitcoin utilizes a totally different system of decentralization, and therefore there’s no reason to dwell on the old centralized systems that didn’t work. List of Investors email database providers

Satoshi himself is adamant about this by mentioning the Chaumian ecash in passing within one of his postings on in the Bitcoin forums. In a post about a different proposal, in his post, he mentions that they are “talking of the previous Chaumian central mint,” however, it could be because it was the only option accessible. Perhaps they’d like to explore a different direction. A lot of people dismiss the concept of e-currency in the same way as an unsalvageable cause due to the fact of the numerous companies that have had failed since the 90’s. It’s my hope that it was the centrally-controlled system that ruined them. It’s the first time we’ve attempted an untrust-based, decentralized system.” This will give us an idea of what Satoshi was thinking about the previous plans, and more specifically, what he thought about how Bitcoin is different. The fact that Bitcoin is decentralized is an important feature that sets it apart from the rest of the alternatives we’ve looked at. List of Investors lists

Another intriguing quote by Satoshi implies that he may perhaps not have the academic credentials. The majority of academic researchers brainstorm ideas and record them in a hurry, before they begin to build the systems. Satoshi claims that he used the his own strategy: “I actually did Bitcoin sort of reversed. Then I wrote the code first before I could be convinced that I would tackle every issue, and then I wrote the document. I am confident that I will be able to publish the code faster than I can write a complete specification.”

Because there’s a an element of mythology about Satoshi It’s worth noting that he did make mistakes just like all of us and wasn’t an accurate predictor that would be useful in the near future. There are flaws and design decisions that are questionable in the initial Bitcoin code, as and in its design. For instance it was possible of sending bitcoins to IP addresses, but it never caught up and, in the end it was a terrible idea. When he explained the benefits Bitcoin could be used for, his ideas were based on the notion of using it on the internet. This use case is fundamental to Bitcoin obviously but it’s not all there is. The vision he gave wasn’t of visiting the coffee shop and paying for your coffee using Bitcoin for instance. List of Investors lists

The last question we can consider, based on what we have learned from the past of digital currency is “Why does Satoshi maintain his anonymity?” There are a variety of motives. For one, it could be to play. A lot of people write their novels in anonymity and there are graffiti artists such as Banksy who remain anonymous. In the community Satoshi was a part of during that time as well as the Cypherpunk community as well as the Cryptography mailing list it was commonplace for anonymous users to write posts.

However there could be legal issues that influenced Satoshi’s decision. There were two U.S. companies, Liberty Reserve and e-Gold have been in legal troubles for laundering money. In 2006 one of the founding members of Liberty Reserve fled the United States because he was afraid that he’d be arrested for money laundering. The E-Gold founders on the other hand remain within the United States, and one was in fact arrested and agreed to plead guilty. The guilty plea was filed at the exact time Satoshi created his Bitcoin website and began sending emails to people with his idea. However, many people have created e-cash systems and no one else was afraid of the legal implications , or chose to keep their identity private. Therefore, while this could have been the cause, however it may not be the main motive. email marketing database List of Investors

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It’s also important to note that some features of ecash were patentable and that some members belonging to the Cypherpunk movement were worried regarding implementing ecash-based systems because of patents. Indeed, one message on the mailing list for Cypherpunks suggested that a group of anonymous coders use ecash to ensure that, if someone did suit, they wouldn’t be able to locate the coders. Although it’s difficult to believe that Bitcoin is in violation of the ecash patents due to how distinct its design and its underlying technology, it is possible that Satoshi was extra cautious. Maybe he was attracted by the concept that a coder was anonymous in the cypherpunk group. List of Investors email database providers

Another reason often mentioned is personal security. We’re aware that Satoshi has plenty of bitcoins he mined at the beginning of his career, and due to the success of Bitcoin, they have become a substantial amount of money. I believe this is an enticing reason. In the end, making a decision to remain anonymous isn’t something you do one time, it’s something is done on a continuous basis. However, it likely was not Satoshi’s primary motivation. When it was the first time Satoshi took on the name Satoshi Nakamoto, he had not published the whitepaper or the codebase that was used to create Bitcoin and it’s difficult to imagine Satoshi had any idea it would become as popular in the way it did. Actually, at several moments in the beginning of its history, Satoshi was optimistic but skeptical about the future of Bitcoin. He was aware that numerous previous efforts were unsuccessful and it was possible that Bitcoin could also fail. List of Investors quality email lists

Conclusion remarks

The growth of Bitcoin is quite impressive when you look at all the other ventures which failed to accomplish what it can do. Bitcoin is a notable innovation such as the block chain, and an uncentralized model that allows transactions between users. It offers a practical but not perfect level of privacy for the users. In Chapter 6, we’ll go over an in-depth look at privacy in Bitcoin. In one way, it’s weaker than the robust anonymity of DigiCash however in another way it’s more secure. This is because in DigiCash the only thing that was protected was the users who were sending the money who kept their identities private, it wasn’t the sellers. Bitcoin offers both senders and buyers (whether customers or merchants) the same degree of privacy.

Let me close with a few lessons that we can draw from Bitc List of Investors listsoin using the lenses of the other systems we’ve studied. First, don’t abandon a problem. Even if people have failed for 20 years when it came to developing digital money doesn’t mean that there’s no system in place that can work. The second thing is to be prepared to compromise. If you’re seeking absolute anonymity or a perfect decentralization, you’ll probably have to improve some of the areas you’ve designed. Bitcoin is, looking back appears to have made good choices. It reduces the anonymity of its users a bit, and demands that users be connected and online the peer-to-peer network. However, it turned out to be a good choice for users. purchase List of Investors email lists

One final point is that success is achieved by numbers. Bitcoin has been able to build an enthusiastic community of users and developers who were willing to contribute to this open source technology. This is a distinct approach to earlier attempts to create digital currency that were created by a corporation with the sole advocates to the system being people working for the firm. The current success of Bitcoin is due to the thriving community of supporters who promoted the technology, enlisted people to use it, and pushed merchants to accept it.

Introduction to Cryptography & Cryptocurrencies

Every currency requires a way to regulate supply and enforce different security features to stop

cheating. When it comes to fiat currencies organisations such as central banks manage the amount of money they have and then increase the amount of money available.

security features that prevent counterfeiting of physical currency. These security features make it harder for an attacker.

But they can’t make it unattainable to steal. In the end, law enforcement is crucial to protect

stopping people from violating regulations of our system. List of Investors consumer email database

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Additionally, cryptocurrencies must be protected by security measures to prevent users from altering the state of the system, or from equivocating. That is, giving contradicting statements to various people. If Alice claims to Bob that she has paid him a digital currency for instance she shouldn’t be in a position to convince Carol that she actually paid the same amount. However, unlike fiat currencies the security requirements of cryptocurrencies must be enforced solely technologically and without the need for an authority central to the system. List of Investors email database providers

The word “cryptography” means that cryptocurrency makes usage of cryptography. Cryptography is a method of securely coding the principles of a cryptocurrency system within the system itself. It can be used to stop tampering and equivocation and also to encode the rules of the creating new units of currency into a mathematical process. To fully comprehend the cryptocurrencies, we’ll need to understand the cryptographic principles they are based on.

The field of cryptography is an extensive academic field that employs a variety of sophisticated mathematical techniques which are notoriously nebulous and hard to grasp. However, Bitcoin does not rely on the use of a few simple and well-known cryptographic structures. This chapter will examine cryptographic hashes as well as digital signatures, two fundamentals which prove efficient in creating cryptographic currencies. The next chapters will cover more complex cryptographic schemes, like zero-knowledge proofs which are utilized in the proposed extensions and changes to Bitcoin.

When we’ve taken in the important cryptographic natives, we’ll examine a portion of the manners by which those are utilized to fabricate digital currencies. We’ll finish this section for certain instances of basic digital currencies that outline a portion of the plan difficulties that we really want to manage. purchase List of Investors email lists

Cryptographic Hash Functions

A cryptographic hash function is the first cryptographic primitive we need to understand. It is a mathematical function that has three properties.

It can input any string of any length. List of Investors lists

It produces an output of fixed size. We will assume that the output size is 256 bits to make the discussion concrete. Our discussion is valid for any output size, as long as it’s sufficient.

It is efficient computable. This means that you can find the output of the hash function for any input string in a reasonable time. Technically speaking, the time required to compute an n-bit string’s hash should be O(n).

These properties are a general hash function that can be used to create a data structure, such as a hashtable. We will be focusing exclusively on cryptographichash function. For a hash function to be cryptographically secure, we’re going to require that it has the following three additional properties: (1) collision-resistance, (2) hiding, (3) puzzle-friendliness.

To understand why it is useful to have a function behave this way, we will examine each property more closely. A cryptography student should be aware of the differences in how this book treats hash functions. Although puzzle-friendliness is not required for cryptographic hash function, it will prove useful for cryptocurrency. purchase List of Investors email lists

Property 1: Collision-resistance.The first property that we need from a cryptographic hash function is that it’s collision-resistant. When two inputs produce the exact same output, a collision is occurring. A hash function H (.) iscollision-resistant if nobody can find a collision. Formally:

Collision-resistance: Ahash functionHis said to be collision resistant if it is infeasible to findtwo values, xand y,such that xy,yet H(x)=H(y).

Although we stated that nobody could find a collision, we didn’t say that there aren’t any collisions. We know that collisions exist and can prove it with a simple counting argument. The input space for the hash function includes all strings of any length, while the output space only contains strings of a fixed length. The input space is larger that the output space, and the input space can be infinite while the output spaces are finite, so there must be input strings which map to the same output string. According to the Pigeonhole Principle, there will always be many inputs that map directly to an output.

If we randomly select 2 + 1, there is a 99.8% chance of at least two of them colliding. We can only examine the square root of the possible outputs to find a collision. This is a phenomenon of probability called the birthday paradox. List of Investors consumer email database

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This is a very general, but not practical, algorithm for finding collisions for any hash function. The more difficult question is, is there another method that can be used to locate a collision for a specific hash function? The generic collision detection algorithm may not be practical to use, but there might be another algorithm that can find a collision for a particular hash function. List of Investors address lists

Application: Message digests. Now that we understand collision-resistance, the next question is: What does collision-resistance serve? Let’s look at one example: If two inputs x and yto a collision resistant hash function Hare are different, it is safe to assume their hashes H (x)and H (y)are different. However, if they knew an xand an ythat were both different but shared the same hash, this would contradict our assumption that His collision resistance.

This argument allows us use hash outputs to create message digests. SecureBox is an online file storage system that authenticates users and allows them to upload files. Let’s say Alice uploads a large file and wants to verify that it is the same file that she uploaded. You can do this by saving the entire file locally and comparing it with the one she downloaded. Although this is possible, it defeats the purpose behind uploading it. Alice can use the local copy if she needs access to the file to verify its integrity. buy List of Investors targeted email list

This problem can be solved elegantly and efficiently by using collision-free hashes. Alice only needs to know the hash of her original file. She later downloads the file from SecureBox and computes the hash. Then she compares it with the one she had previously saved. If they match, she can confirm that it is the file she uploaded. However, if the hashes differ, Alice can conclude that it was altered. Remembering the hash thus allows her to detect accidentalcorruption of the file during transmission or on SecureBox’s servers, but also intentionalmodification of the file by the server. These guarantees are essential to cryptography’s ability to detect malicious behavior from other entities. List of Investors lists

The hash is a fixed-length digest or unambiguous summary of a message. This allows us to quickly recall things we have seen and help us recognize them again. The entire file could have been gigabytes in size, but the hash has a fixed length of 256 bits for our hash function. This significantly reduces the storage requirements. We’ll be discussing applications where a hash can be useful as a message digest later in this chapter.

Property 2: Hiding This property cannot be true in its stated form. Let’s take an example. We will flip a coin. If the result of the coin flip was head, we will announce the hash string “heads”. If the result of the coin flip was heads, we’ll announce the hash for the string “heads”.

Then, we ask an adversary (who didn’t see this coin flip but saw the hash output) to determine the string that was hashed. We’ll soon understand why this game is so popular. They would then simply compute the hash for the string “heads” as well as the hash for the string “tails” to see which one was given. In just a few steps they can determine what the input was. buy List of Investors targeted email list

Because there were only two possible values for x, the adversary was able guess the string. It was also easy to try both. To be able achieve the hiding property, it must be clear that there is no value of x which is especially likely. This means that xmust be selected from a set that is in some way very distributed. This method of trying to find a few likely values of x will not work if xis selected from such a set.

The big question is, can we attain the hiding property if the values we desire are not from a spread-out group like in our “heads” and “tails” experiments? The answer is yes, Perhaps we can conceal an input that isn’t spread out by concatenating with another input that has been spread out.

Information-theory uses min-entropy to measure how predictable an outcome is.

Min-entropy refers to the intuition that the distribution (i.e. random variable) is extremely spread out. This means that we can’t sample from the distribution and find any particular value.

It’s very likely that it will happen. For example, let’s say that ris is chosen uniformly among all the strings. List of Investors consumer email database

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If the length of a string is 256 bits, it was selected with probability 1/2, which is an infinisimally small value.

Application: Commitments. Now let’s examine an application of hiding property. We are referring to a “commitment” in particular. This is the digital equivalent of taking a value and sealing it in an envelope. Then, we will examine how to apply the hiding property. You have committed to the contents of the envelope by doing this. You haven’t yet opened the envelope, so even though it’s your commitment to a certain value, it remains secret from others. You can later open the envelope to reveal the value you have committed to. List of Investors address lists

First, generate a random nuce to use in a commitment scheme. The commit function is then applied to the nonce along with msg (the value being committed too), and the commitment com is published. This stage is similar to putting the sealed envelope on a table. If we wish to reveal the value they have committed to previously, we will publish the random nonce we used to create the commitment and the message,msg. Now, anyone can verify that msg was the message that was committed to earlier. This is similar to opening the envelope.

to the contents of the envelope. It’s impossible to find two messages. You can’t commit to one message and later claim you have committed to the other. buy List of Investors targeted email list

How do we determine if these properties are true? Before we can answer that question, we must discuss how we will actually implement a commitment program. This can be done using a cryptographic haveh function. Take a look at the following commitment scheme.

To commit to a message we generate a random nonce of 256 bits. Next, we combine the nonce with the message to generate a hash and return the commited value. Someone will then compute the same hash of nonce that they received concatenated to the message. They will also check if that is equal to the commitment they saw. List of Investors lists

Let’s take a look at the properties we need for our commitment schemes.

The commitments hiding property is precisely what we needed for our hash functions. If key was chosen randomly as a 256-bit value, then the hiding property states that it is impossible to recover the message from hash output if we hash keyand the message. It turns out that the binding property can be implimented by1 the collision-resistant property in the underlying hash functions. buy List of Investors database for marketing

This means that if He has a collision-resistant and hiding hash function, the commitment scheme will work in that it will have all the security properties.

Property 3: Puzzle friendliness. We will need the third security property from hash functions to be puzzle-friendly. This property is quite complex. First, we will explain the technical requirements for this property and then provide an application to show why this property is so useful.

This means that it is very difficult to find another value to match the target if the input is selected in a random way.

Application: Search puzzle. Now let’s look at an application that illustrates this property’s usefulness. This application will build a search puzzle. It is a mathematical problem that requires us to search a large space to find the answer. A search puzzle is not easy to solve. This means that there is no other way to find the solution than by searching large spaces. The opposite is not true. List of Investors lists

Search puzzle. Search puzzles consist of List of Investors email database free

A value, id (which we refer to as the puzzle-ID), is a value that was chosen from a high min entropy distribution

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This intuition states that H can accept any 2nvalues if it has an output of n bits. The input must be found so that the output falls within Y. This set is usually much smaller than all other outputs. How difficult the puzzle is will depend on how large Y is. The puzzle will be trivial if it has all the n-bit strings, but the one element puzzle will be the most difficult. There are no shortcuts because the puzzle ID has high min-entropy. However, cheating could be done if the ID had a certain value. For example, pre-computed solutions to the puzzle using that ID. List of Investors address lists

Puzzle-friendly means that a search puzzle can be solved in any way that is possible. This is true even if the puzzle-IDs are generated in an appropriately random manner. This idea will be used later in our discussion about Bitcoin mining.

SHA-256. We have discussed three properties and one application for hash functions. Let’s now discuss one particular hash function we will use in this book. There are many hash functions, but this one is the most popular and widely used. It is called SHA-256. buy List of Investors database for marketing

Remember that our hash functions must work with inputs of an arbitrary length. As long as we are able to build a hash functions that work on inputs of fixed length, there is a generic way to make it work on inputs of arbitrary length. This is the Merkle-Damgard transformation. This method is used by SHA-256, which is just one of many commonly-used hash functions. Common terminology refers to the compression function, which is a fixed-length collision-resistant hash functions. It has been shown that the overall hash function will also be collision resistant if it is collision-resistant.

It is very simple to use the Merkle-Damgard transformation. The Merkle-Damgard transform is very simple. The input length of the compression function will be (m-n+ n=m). We use an Initialization Vector instead for the first block. This number is used every time the hash function is called. In practice, you can simply look it up in a standard document. You return the output of the last block.

SHA-256 uses a compression algorithm that accepts 768-bit inputs and produces 256-bit outputs. Block size is 512 bits. For a graphic representation of how SHA-256 works, see Figure 1.3. buy List of Investors database for marketing

We have already discussed cryptographic hash function, hash functions that are cryptographic functions with special properties and their applications. Now we will discuss a particular hash function that is used in Bitcoin. We’ll be discussing how to use hash functions in order to create more complex data structures for distributed systems such as Bitcoin.

Sidebar: Modeling hash functions. Hash functions are the Swiss Army Knife of cryptography. They can be used in an amazing variety of applications. This versatility also means that different applications will require different properties for hash functions in order to guarantee security. It is notoriously difficult to identify the properties of hash functions that will provide provable security for all applications. List of Investors lists

We’ve chosen three properties that are critical to how hash functions work in Bitcoin and other cryptocurrency. These properties may not be necessary for all uses of hash functions. As we’ll see, Bitcoin mining is not the only area where puzzle-friendliness can be important.

Secure systems designers often give up and create model hash functions, functions that produce an independent random value for each input. Cryptography is still a controversial area. It doesn’t matter what your position is on the issue, it is important to think about ways to decrease the security properties we want in our applications. This can be useful intellectual exercise for building secure system. This chapter is intended to teach you this skill. List of Investors email database free

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This section will discuss hash pointsers and their applications. A hash pointer can be a data structure that is useful in many of these systems. A hash pointer simply points to the location of information, along with a cryptographic hash. A regular pointer allows you to retrieve the information. However, a hash-pointer can also be used to verify that the information has not changed. List of Investors database for sale

You can create all sorts of data structures using hash pointers. We can intuitively take a data structure such as a binary search tree or linked list and use hash pointers to implement it.

Block chain. In Figure 1.5, we created a linked list with hash pointers. This data structure will be called a block-chain. Unlike a regular linked listing that has a series blocks, each block contains data and a pointer at the previous block. In a block-chain, the block pointer to the block before it is deleted will be replaced by a hash key. Each block contains not only the value of the block before it, but also a digest that shows us the current value. This allows us to confirm that the value hasn’t changed. The head of the list is simply a regular hash-pointer that points at the most recent data block.

One use case for a blockchain is a tamper evident log. This means that we want to create a log data structure which stores lots of data and allows us add data to the log. We will detect if someone alters the data in the log. List of Investors database for sale

Let’s look at what happens when an adversary tries to alter data in the middle of a block chain. This will help us understand why block chains have this tamper evident property. The adversary wants to do this in a way that anyone who only knows the hash pointer at block chain’s head won’t be able detect the tampering. The adversary alters the data in block k. This means that the block k+1 hash, which is a hash for the entire block, will not match up. Because the hash function is non-coincidence resistant, statistically we can guarantee that the new hash won’t match the altered content. So we can detect inconsistencies between the block k data and the block k+1 hash pointer. The adversary could continue trying to cover this up by changing the hash of the next block. This strategy can be continued by the adversary, but it will not work once he reaches top of the list. The adversary can’t change any block as long as the hash pointer is stored at the top of the list. List of Investors lists

This means that the adversary will have to alter the hash pointers back to the beginning if he wants to tamper any data in the entire chain. He won’t have the ability to alter the head of the list, so he will eventually run into a roadblock. It turns out that just by remembering one hash pointer, all we have is a tamper evident hash of the entire list. This block chain can be used to build as many blocks as you want. We will refer back to the genesis block, which is the block at the start of the list.

It may be obvious that block chain construction looks very similar to Merkle-Damgard construction, which we discussed in the previous section. They are very similar and both have the same security argument. List of Investors email database free