比特币区块链那些事

1. Bitcoin’s code Bitcoin began in 2009, and a vision document and system source code were released together. Bitcoin’s introductory video simply describes it as “the first decentralized digital currency,” with a more detailed explanation stating that “the essence of money is that any accepted currency within a specific national or socioeconomic context , a thing or record that can be used to pay for goods and services or to repay debts. Based on this concept, Bitcoin is designed around how to apply cryptography to control the supply and circulation of money without relying on any central government." These two paragraphs of explanation emphasize that decentralization and reliance on computer algorithms are fundamental principles in the design of Bitcoin and derivative virtual currencies. Without a central bank (or server) to confirm transactions, Bitcoin relies on a "peer-to-peer" network, personal keys and computational tasks to provide "credentials" for transactions between strangers. Bitcoin is not linked to any other currency, commodity, or national economy. Bitcoin exists because of its user network, and only exists in its user network. Bitcoin is technically designed so that Bitcoin transactions do not require any physical exchange process (such as coins or banknotes), nor do they require any central official agency to record them (such as bank transactions). Instead, the network determines the validity of transactions through the blockchain, a task that collectively computes a “proof of work.” The design aspect is crucial to the functionality of Bitcoin, otherwise a user might spend his Bitcoin twice, expecting the distributed system to not know that the coin no longer belongs to that person. Without getting into the details (interesting but not particularly relevant to this chapter), Bitcoin relies on hashing -- an intensive and irreversible computational process -- that participating users run on their machines to determine which transactions are actually valid. . The key point here is that the hash operation is designed to be completed by the Bitcoin network in about 10 minutes, with the resulting operation result confirming the validity. Any false transaction, such as the theft of all Bitcoins, must compete with all computers in the network for hashing to confirm the transaction. Therefore, false transactions cannot be propagated through the end-to-end network, only real transactions can, ensuring the smooth operation of the monetary system.Bitcoins are stored by users in electronic wallets located locally on their computers or online, making them both potentially lost and stolen; however, Bitcoins can be backed up like any other information. As mentioned above, all Bitcoin transactions are public, but individual users’ electronic wallet addresses are not shared unless a user chooses to actively disclose them. Therefore, Bitcoin is a semi-anonymous transaction system, and it is difficult (although possible) to trace transactions back to individuals. Despite (or precisely because of) its origins in crowdfunding, Bitcoin has grown tremendously. As of June 2015, the total market value reached US$3.6 billion, accounting for more than 80% of the total market value of all decentralized virtual currencies. While the total number of these so-called cryptocurrencies reaches more than 600 (most of which are copied from the Bitcoin system), only 10 currencies have a total market capitalization of more than $10 million, and 42 exceed $1 million. Although Bitcoin is absolutely dominant among virtual currencies, the actual transactions of Bitcoin are relatively few, "about 69,000 per day globally." Compared with the 274 million non-cash retail transactions that occur every day in the EU, Bitcoin transactions The amount appears to be minuscule. Not surprisingly, only a handful of businesses accept Bitcoin, with the European Central Bank estimating that only 3 in 10,000 merchants will accept the virtual currency. Some major companies, most notably Expedia, have begun accepting Bitcoin payments for hotel reservations. However, Expedia does not directly record virtual currency into its account, but designs a payment process to convert Bitcoin into a country's legal currency before receiving payment. Clearly, Expedia is only using Bitcoin as a payment medium, not as a long-term store of value. Bitcoin has always faced the challenge of low transaction volume, which has also led to severe fluctuations in Bitcoin value and limited liquidity. 2. Legality of Bitcoin Although Castronova believes that “since there is no law explicitly prohibiting it, virtual currency is completely legal”, Bitcoin still needs to face many unresolved legal issues. Although it faces concerns about funding illegal activities, Bitcoin is also widely used in legal and mainstream economic activities, such as booking hotels through Expedia.It is undeniable that the area where Bitcoin has the greatest potential and disruptive effect is in facilitating transactions, especially cross-border payments. Although the existing bank wire transfer and credit card systems have become relatively popular for cross-border payments, the fees charged by intermediaries are relatively high. Therefore, if a payment system is designed, the company receives "a country's currency, converts it into virtual currency, transfers it through the virtual currency network, and then converts the virtual currency into the currency of the country where the payment is received and arranges payment." Virtual currencies such as Bitcoin Currency will play a huge role in such a payment system. In other words, Bitcoin may in practice be used primarily for short-term transactions, rather than fulfilling all the functions of a currency, such as a store of value or unit of account. Still, bank officials were careful to note that “legally speaking, Bitcoin is not a currency and does not have the status of legal tender nor does it meet the standards of a financial instrument.” In addition, governments of various countries have repeatedly issued risk warnings about the use of decentralized virtual currencies. Given the nature of this "risky behavior," key members of the Bitcoin community have clearly begun to cooperate more with government agencies. One of the members of the Bitcoin development team, Jeff Garzik, publicly stated, “We are working with the government to ensure that Bitcoin is under government supervision...The only way Bitcoin can succeed is to cooperate with the government and Cooperation with regulatory authorities.” The announcement sparked a huge (mostly negative) reaction among Bitcoin users, as the ideology behind the Bitcoin project generally rejects state-led regulation or even cooperation. 3. The ideology of Bitcoin The protests of the Bitcoin community are related to the fact that Bitcoin carries the core values ​​of hacker culture summarized by Levy, namely distrust of authority and decentralization, and open access to computer systems (this characteristics aligned with the open source movement), and the ultimate use of computers for the benefit of humanity. Based on these values, Bitcoin aims to detach (for better or worse) from the modern financial system, or, more precisely, from specific aspects of the financial system and the larger regulatory process. It is valuable to go back to the original concept paper published by Nakamoto (Bitcoin creator) in 2009, which opened: Commerce on the Internet has completely relied on financial institutions as trusted third parties to process electronic payments. .Although this system works well for processing most transactions, it faces the inherent flaws of this trust-based model. Since financial institutions cannot avoid mediating disputes, completely irreversible transactions are virtually impossible. These mediation costs increase transaction costs, limit the minimum viable transaction size, and eliminate the possibility of small casual transactions. There is also a broader cost of being unable to achieve irreversible payments for services that are irreversible. Since transactions can be reversed, the need for trust is even broader. Merchants must be wary of customers and ask for unnecessary information, and a degree of fraud is considered inevitable. These costs and payment uncertainties can be avoided in cash transactions, but there is no mechanism to ensure the security of online payments without a third party. What is needed now is an electronic payment system based on cryptographic proof rather than trust, so that any two parties can conduct transactions directly without the need for third-party guarantees. Transactions that are computationally difficult to reverse protect buyers from fraud, and regular escrow mechanisms can be easily implemented to protect buyers. This vision highlights the contrast between the "trust model", which has "flaws", "transaction costs" and "hassles", and the "crypto model", which allows for "regular" and "direct" transactions and Able to "protect" both buyers and sellers. In the original text, Satoshi's vision replaced the complexity of socially embedded money under the supervision of a central authority, proposing the idea of ​​using information flows and computer code to conduct direct transactions without the need for social connections or institutions, especially banks. This basic idea is replicated through the "Bitcoin Rhetoric", "Bitcoin has many advantages over alternatives. Bitcoin enables direct person-to-person transactions over the network without going through a bank or clearing house. This means that transactions The fees will be much lower, you can use it in any country, your account cannot be frozen, and there are no prerequisites or restrictions.” In short, Bitcoin calls for the disintermediation of the entire financial system, and in addition, the disintermediation of trust in the entire society.This is a profoundly libertarian vision, also reflected in the discussion of economic concepts such as inflation and deflation on Bitcoin’s wiki page. In addition to a fuller overview of Hayes and Keynesian macroeconomics, and the rejection of the labor theory of value as a "universally accepted error," the wiki page also provides a link to an interview with Milton Friedman, Among them, Friedman "proposed to replace the central bank with computers and fix the annual growth rate of the money supply at 4%." There are no objections to these statements and links in Wikipedia's discussion forum (which displays the edit history or any comments). Those who have studied high-tech culture are not surprised by the liberalism of Bitcoin. Given that these cultural values ​​are embedded in software, the ideologies of virtual currency founders are also spreading as software systems rapidly expand. This means that the spread of Bitcoin is not simply a new payment method, but also accompanied by the grand project of replacing certain values ​​- replacing socially (and geographically) embedded and orchestrated trust systems with code and cryptography. As Lessig puts it: “We can build, architect, or code cyberspace to protect the values ​​we believe are vital. Or we can build, architect, or code cyberspace so that those values ​​disappear. There’s no room for maneuver. None. Does not include the option of a certain construction. The code will never be found; it is only what has ever been made, and only by us”. It is for this reason that understanding the politics behind a transformative economic innovation like Bitcoin is extremely important. After all, virtual currencies are blurring the boundaries between individuals, commodities and countries in unpredictable and innovative ways. Just as new digital spaces provide a venue for “real” economic activities, decentralized currencies are also providing tools for “real” economic transactions. #BTC #ETH #Bitcoin