The author | Ben Wizner
The translator | Xu Jin
American Edward Snowden in 2013 in Russia to apply for asylum, and has been living there. In exile he expressed bitcoin’s favorite, but in the future the crypto currency, he believes bitcoin will eventually disappear. But the use of encryption currency but not with bitcoin disappear and end.
In an interview with ACLU privacy and technology project director Ben Wizner said in an interview, Snowden bitcoin and other basic value chain block encryption based on very limited monetary assets. But bitcoin is still feasible in the short term, the first is because bitcoin scarcity leads to limited supply. Bitcoin, a total of not more than 21 million, and has 17 million bitcoins were “mining” out. This scarcity has led to competition, to tap the remaining millions of bitcoin, which alone can provide certain value for the. Second is the most common people think that it is a “real” means of exchange. According to Snowden’s view, if someone wants to be in the absence of central bank in the case of the network transfer funds, encryption currency is still likely to be seriously.
He also criticized the blockchain technology at present, that the two main consensus now is not good enough, should go to the development of new pattern. He described the “proof of work” is conducive to the rich environment of destructive activity. The block chain, “new technology like all, there will be cases of abuse”.
Ben Wizner Snowden think that he’s seen the smartest, most patient who is also a technical evangelist and no sense of superiority. InfoQ will they dialogue translation and sorting.
Ben Wizner (hereinafter referred to as BW): Recently, the Electronic Frontier Foundation joked: “people who describe what is used in the download block chain and how to become the future of the currency will be distributed in tweets, and instant messaging energy will soon exceed the total energy of the whole country of denmark”. There are indeed many block chain technology evangelist society”. However, ashamed to say, I still don’t know exactly what is the chain block.
Edward Snowden (hereinafter referred to as ES): You want to hear a maths lesson? I have waited long for this day. Do you remember what is a cryptographic hash function?
BW: I don’t remember what is a cryptographic hash function, and maybe I don’t remember.
ES: Let’s start with a simple question: how much do you know about the blockchain technology mysterious?
BW: If I had listened to you in four years ago, now may become very rich? In fact, I heard a lot of related concepts, but in fact only a little, for example: “center”, “ledger”. What is the block chain?
ES: Basically the blockchain is a new database. Imagine all the data blocks in the chain will update with new form of data added to the end of the blockchain, but will not change the original existing data. That is to say, you can block at the end of the new data link, let the extended chain block. We start from the concept, with our in-depth exchanges, this concept will become gradually enriched.
BW: Okay, but why are you doing this?
ES: Simply, in order to trust. Imagine, in the other database, through a simple edit and save can modify a data entry, such as our bank information. If someone can be free to change your balance is zero, then it must feel bad, right?
The key is, if a system can at any time to let someone can change the history data only through simple keyboard input, then you can only believe that most people are very kind, but in human nature this, humans are not the good record. The blockchain goal is to achieve the history can not be tampered with.
BW: What history?
ES: Transaction history. An example of a block chain of the earliest and most famous is bitcoin, it is a new form of currency. However, in recent months, we have seen people start information of various types stored in the block chain, any need to be remembered or can not be tampered information can be stored in the block chain, such as health records, contracts and contract.
When thinking about the block chain from the technical level of the most basic, it is just a time stamp to record data. This can be proved by the time stamp in the post data has never been tampered with. The first one is created bitcoin, which is also called the genesis (Genesis Block), on the block with a very famous “evidence”, until today you can still see.
BW: Block chain just transaction history. This sounds a bit disappointing, because I have heard very exaggeration. For example: the block chain is about censorship in response to block chain is a response to online platform monopoly.
ES: Many statements which is just speculation. Block chain theory can be applied in many fields, but it is best to understand the mechanism. In fact, we are a very simple concept in the discussion, one of the most important point is that the block chain application all the different variants of the same subject: a verifiable account.
The concept of the database is to block the integration of small, the data can be any information. When it comes to money, can be said to be trading records, of course, can also be pet pictures, download links, or even a chess every step of the way, then we will in a complex way to make these data mark. If you’re afraid of math, so you can think of it as a “notary high-tech field”. Finally, we will release these new data have been certified to other members of the network. Other members of the network will verify the data, after verification by will update their local blockchain record copy. Another point to the final block chain is to ensure that no one can fabrication and falsification, because in the block chain network there are too many people have the same original blockchain record copy.
So go to the center of the design based on some people hope to have a new means to overthrow the current censorship and ingrained monopoly. Imagine a world where all the important data are stored in the public only GenericCorp company, it will be at the expense of playing these data at the expense of the public interest, and it will do. But there is no decoupling mechanism or “let us do evil” button in this world, because if you need to create a global consensus on such a mechanism, usually requires at least 51% network support to change the rules.
BW: So, even if Peter Thiel wins, and obtained the permission of the court, all about Peter Thiel is a “modern vampire” article must be deleted, but if these articles were published in the Journal of the blockchain, there is no way to delete, right?
ES: Yes, as long as the article published in the Journal of block chain chain block to the center of the public on, even though they may be to make a judgment, even ordered them to set fire to the office, but this does not affect the block chain in the network.
BW: Then, the block chain is how to work?
ES: It is the most interesting part of which you now ask. Ready to learn some abstract mathematical knowledge is?
BW: I’m ready。
ES: We use a virtual block chain blog as an example to start. As mentioned earlier, the block chain has a very interesting mathematical characteristic, namely the data block after the launch of the chain will have the immutable nature.
For simplicity, can be a new post as a new data block block chain. Every time you publish a new article, you can add another block to block at the end of the chain. Even for an old article in the revision, will add a new block at the end of the blockchain, and does not change or erase any old block. If your primary focus is the review of the relevant system, then the block chain that will no longer be the problem. Because as long as the release of this article in the block chain, it means that it will never be erased. To remove any one block from a block in the chain, and without destroying its block is not possible, because if you want to change before the block, but also to convince other members of the network agree with you to modify the block is correct.
I’ll take a little time to explain why this is hard to do. Because behind the blockchain data records have magical mathematical algorithms in support. What is stopping you outside of the chain end block place to add a new block? Or what is stopping you change an existing link?
We must clearly understand what we’re trying to record, or to prove the authenticity of a time stamp.
So, from a technical perspective, the working principle of the blockchain is this: will the new block (i.e. blockchain a snapshot of the data block) mathematical equivalent with it in front of the adjacent blocks and a timestamp (as time sequence released) together, and then through a certain way they “hash” together, to prove that the new block line to join the blockchain conditions.
BW: “Hash” is really a verb?
ES: The password hash function is actually a math problem, convert any input data in a predictable manner. Whenever you enter a hash function to a picture of a cat, always get the same number, we take this result is called a hash of the value of the image, i.e. the cat image input to a mathematical problem of hash. Here is the key concept to understand is that if the cat image to the same hash function is different, or make some minor changes to the same cat image, then the hash function will be completely different numbers (hash value).
BW: You can put any type of data input to the hash function? Can the hash Bowen, financial transactions or “Moby Dick” (Moby-Dick)?
ES: Yes。 Therefore, we can carry out a hash of these different blocks, the blocks just about financial transactions, network links, medical records and other data update. Added to the block of each block in the chain through the new hash value identification and verification, generating a hash value data contains a hash value before the block. It is a complete chain has been extended to the first block, this block contains a chain block name.
I have omitted some technical nuances here, but there is a very important concept, all the current block in the chain are verifiable, they are in strict accordance with the chronological order, and are not variable. Each create a new block (bitcoin for example, every 10 minutes will generate a block), once again verified before all the blocks of the content, so that the old blocks in the block chain completely destroyed under the condition of more and more difficult to change.
So, when Peter Thiel heard that he was dubbed the “modern vampire” and want to block the message, the message on the block chain has created thousands of publicly verifiable records, historical block.
BW: Then… This can save the Internet? Can you explain why some people think that the future may be able to bypass the chain block or replace the large technology company monopoly? For example, why it can weaken the Amazon or Google?
ES: I think this is their wishful thinking, at least in the foreseeable future is like this. Think about the common examples in the database before the bank balance example. This set looks fast, cheap and simple, but easy to be called “trust mechanism” abuse. Block chain at the cost of efficiency, eliminating the dependence on the “trust mechanism”. At present, Visa and MasterCard and other veteran organizations can handle tens of thousands of transactions per second, and can only handle about 7 bitcoin transactions. At the same time, people are also research methods make up the disadvantages of the efficiency, in the next few years we will see the blockchain exchange rate will be increased, the efficiency is the main problem we will no longer worry.
BW: Now is the time to explain the principle of bitcoin, although I try to avoid asking this question.
ES: Block chain most significant and application scenarios is the most famous with money.
BW: To solve the problem of money chain block what aspects?
ES: Block chain also solved the problem of trust. Specifically: what is money? At best is a piece of paper, right? But most of the time, it is only the balance of records in the database. For example, a bank that you have 300 rupees for today, tomorrow you must hope they do say, or have more money for.
Now, imagine the database the so-called reliable account balance, they are just floating numbers, is temporary. If you are a bank account of people, perhaps because your account does not meet the conditions of the bank, may also be the place you live in the bank is not reliable, or just before Cyprus happens, the bank decided to use the savings to help them out of difficulties. Perhaps the monetary system itself is not perfect, just like in Venezuela or Zimbabwe, you can also buy the balance yesterday today but can’t buy a cup of coffee. This is the failure of the monetary system.
BW: Wait a minute。 Why bitcoin itself has value? What is the value? It is behind what support? When I have bitcoin, what I really have?
ES: Good question. What makes a small paper worthwhile? You may think of scarcity, practicality and common belief of currency as a store of value or a means of exchange.
Now let us put aside without fundamental value notes: why the value of gold is far more than its actual use in the industry? Because many people believe it is worth more than its actual value. Indeed, it is generally believed that dug from the ground and then carved and placed on the shelf to very expensive price, and other people have very high expectations of its value. This idea of this kind of boring metal became the world’s oldest store of value.
Block chain encryption based on currency (bitcoin) the basic value is very limited: it is at best a token (token), so you can save data to block chain blocks, then block chain network participants a historical record keep copies for you. But at least there is scarcity of some encryption currency is true: to date, the total bitcoin does not exceed 21 million, and has 17 million bitcoins were “mining” out. “Mining” equipment and power consumption will be the rest of bitcoin worth hundreds of millions of dollars, many economists argue that it is these equipment and power in support of bitcoin.
However, the most important is that the only factor with the encryption currency value is more people as a means of exchange can be used on the belief. This belief is how money without encryption bank participation under the daily transfer of huge amounts of money in the world through the network. One day, the capital of bitcoin will disappear, but as long as someone wants to transfer the funds in the absence of central bank under the condition of encryption currency still is likely to pay attention to.
BW: What do you think? You love what is it?
ES: I love bitcoin transactions, because they are open and fair. If none of the participants agree that transactions can not be stopped or withdrawn. But in the old financial system, if the United States bank does not want to be a person like me handling transfers, like its peers, has great power and influence, can achieve this point. If a person is a teenager in Venezuela for Paris to make network development related work, he hopes to hard currency (Hard Currency) way to get his reward, but this is prohibited by local currency controls, but he was able to achieve encryption through currency. Bitcoin is not the real private money, but it is the first free currency.
Bitcoin also have a rival. A project called Monero used a means to make encryption transactions more difficult to track transactions must first play a shell game in order to carry out the transaction. Scholars also put forward a new method, called Zcash, to achieve real private transactions using mathematical novel algorithm. But if in five years has not had a private transaction, then I believe that it involves legal issues, rather than technical problems.
BW: So, if Trump wants to cut off your life, don’t let the bank for your presentation fee, you can still get paid by the electronic money on?
ES: Yes, Trump can do is just on the side to send a tweet.
BW: But I think, sometimes the government to track and stop trading is also a kind of social welfare. For example: tax, sanctions, illegal financing etc..
We hope you can make a living, but also hope to be able to corrupt oligarchs sanctions to work.
ES: If you are worried about the rich cannot tax if not bitcoin, I’m afraid I have some bad news. I think most people would agree that the world government authority has not reached its lowest point, people must put them on the Internet and get the money into another real money to spend on luxury goods, so the government is really worried about the day seems very distant.
BW: Then bitcoin cash demand will also affect the Venezuelan children?
ES: This depends on the size of the. A Venezuelan girl wanted to bitcoins as payment of the monthly salary, she does not need ID card and bank. This is our daily barter cash level, especially in developing economies. However, when a corrupt oligarchs want to entrust a $400 million yacht, yacht manufacturers have no monetary circulation so big, but the Internet contact funds meant that the police will ask you how to pay the money.
Similarly, for the government, jointly combat criminals like Binladin is much easier than to suppress Ai Weiwei such dissidents. The French will Chinese work together to track bin Laden bitcoin wallet, but Ai Weiwei is not necessarily so.
BW: So you mean, this basically does not really help those powerful.
ES: In fact, it may bring trouble to them, because if you want to use the block chain, they must put their evidence of wrongdoing to the block in the chain, as we know in the past ten years, government investigators have very strong penetration ability.
BW: If the block chain has a fault, what do you think?
ES: Like all new technologies, there will be chaos and abuse. The problem is its influence is positive or negative. One of the biggest disadvantage is the inequality of opportunity: the new technology is not so easy to be used, it is difficult to understand. Only if it is assumed that we can get the generally available technology, infrastructure and education level, can accept these new technologies. And think about the explosive effects caused by globalization of world economy, the winner will gain huge profits, and the failure of a party will be subject to the same degree of loss. Some institutions can master the advanced technology of the block chain, and globalization for the economy caused by the effects of the truth is similar.
BW: But the Internet economy has shown in money and power is centralized under the premise, can still be done to the center of the platform.
ES: It really is. In fact, there are more relevant technical criticism, but we are not going to discuss today range. Then I want to say, encryption currency is usually realized by one of the two systems, they are “proof of work (proof of work)” and “(proof of stake) to prove ownership”, but they are in the protection system against attacks but with evil. In fact, the two are not good enough. “Proof of work” to reward those who can afford the infrastructure and energy consumption of most people, this is destructive, and is conducive to the rich. “Equity proof” attempts to directly reward directly to the rich to reduce damage to the environment. Obviously, we need a new current mode.
BW: Can you talk more about the environmental hazards. Why is this magic of electronic money to spend so much energy?
ES: Okay, now imagine you decide on bitcoin mining work. Do you know their limited number, but they must come from somewhere, right? Indeed, in the next few years, every 10 minutes there will still be a new bitcoin “mining” to be absent. To distribute bitcoin, bitcoin founder designed a very clever scheme: a global mathematical contest. About every 10 minutes, a new round of the game the winner will get the first round of the reward: a full new, never used bitcoin chest. In order to ensure the reward will not be so fast to get a math problem, the difficulty will be according to the recent problems rate increased. This mechanism also explains why no matter how many players participate in the competition, each round will cost about 10 minutes.
But these methods failed to explain why bitcoin has become so successful. Once only a few cents to win a round return, now it is about 10 million, so people put a lot of energy and full of computer equipment and data center transfer to mathematics or mining contests. The huge “Godzilla” was also calculated into a math competition, make it more difficult to understand.
This means that the biggest winners are those who can come up with tens of millions of dollars to solve a series of problems of the people have no meaning world without end, in addition to these problems, let bitcoin mining contain block chain is more difficult to attack, really meaningless.
BW: “It sounds like a meaningless question like” a series of world without end… Nihilism. Because of constant speculation, I also want to know the blockchain. Some of the government that bitcoin is a threat to world order, but some investors swore that the blockchain will usher in a golden age of transparency. But you tell me this is basically a new distributed database.
ES: Technology is, the most important is the underlying problem, what do the practical application of the chain block. In fact, the real problem is not the “block chain is what”, but “how to use it”. This goes back to the first question: trust. We live in a world where everyone is lying, even Instagram the ordinary young people are also trying to pretend to create a way of life they don’t have on Instagram. For the same search, people will get different results. Everything needs to trust, but on the other hand, not what can be trusted.
A block chain is interesting: it may be a small gear, so that we can create a system of trust. You already know the key block chain: although they are boring, inefficient or even some waste, but if properly designed, the block chain could not be tampered with. This is full of sophisticated boring world, that something is true, is a complete progress. These data may be your bank account deposits, may be manufactured to a pair of Nike shoes, you may also be called to have a permanent record of the president’s office to talk, all of these records will be converted to a block block chain, at the same time they are open, the world no one can see.