bitcoin白皮书中英对照
- 官网：https://bitcoin.org/bitcoin.pdf
标题:
- English: Bitcoin: A Peer-to-Peer Electronic Cash System
- 中文: 比特币：一种点对点的电子现金系统
作者: Satoshi Nakamoto/中本聪
- satoshin@gmx.com
- www.bitcoin.org
摘要 (Abstract)
- English: A purely peer-to-peer version of electronic cash would allow online payments to be sent directly from one party to another without going through a financial institution. Digital signatures provide part of the solution, but the main benefits are lost if a trusted third party is still required to prevent double-spending. We propose a solution to the double-spending problem using a peer-to-peer network. The network timestamps transactions by hashing them into an ongoing chain of hash-based proof-of-work, forming a record that cannot be changed without redoing the proof-of-work. The longest chain not only serves as proof of the sequence of events witnessed, but proof that it came from the largest pool of CPU power. As long as a majority of CPU power is controlled by nodes that are not cooperating to attack the network, they'll generate the longest chain and outpace attackers. The network itself requires minimal structure. Messages are broadcast on a best effort basis, and nodes can leave and rejoin the network at will, accepting the longest proof-of-work chain as proof of what happened while they were gone.
- 中文: 纯粹的电子现金点对点版本将允许在线支付从一方直接发送到另一方，而无需通过金融机构。数字签名提供了部分解决方案，但如果仍需可信第三方来防止双重支付，则其主要优势就不复存在。我们提出一种使用点对点网络解决双重支付问题的方法。该网络通过将交易散列并纳入一个基于散列的工作量证明链中来为交易打上时间戳，形成一个除非重新完成工作量证明否则无法更改的记录。最长的链不仅是对所见事件序列的证明，而且证明它来自最大的 CPU 算力池。只要大部分 CPU 算力由不合作攻击网络的节点控制，它们就会生成最长的链并超过攻击者。网络本身需要极简的结构。信息以最大努力为基础进行广播，节点可以自由离开和重新加入网络，并接受最长的工作量证明链作为它们离开期间所发生事件的证明。
- 简单解析：
要解决什么问题？ 网上支付为啥必须通过银行或支付宝？因为怕有人“一笔钱花两次”（双花问题）。
解决方案是啥？ 我们搞一个点对点的网络和一套公开的记账系统。记账需要付出电脑算力（工作量证明），记好的账本连成一条链。想篡改账本？你得重算所有账目，这几乎不可能。只要网络里好人占多数，这个系统就牢不可破。
1. 简介 (Introduction)
- English: Commerce on the Internet has come to rely almost exclusively on financial institutions serving as trusted third parties to process electronic payments. While the system works well enough for most transactions, it still suffers from the inherent weaknesses of the trust based model. Completely non-reversible transactions are not really possible, since financial institutions cannot avoid mediating disputes. The cost of mediation increases transaction costs, limiting the minimum practical transaction size and cutting off the possibility for small casual transactions, and there is a broader cost in the loss of ability to make non-reversible payments for non-reversible services. With the possibility of reversal, the need for trust spreads. Merchants must be wary of their customers, hassling them for more information than they would otherwise need. A certain percentage of fraud is accepted as unavoidable. These costs and payment uncertainties can be avoided in person by using physical currency, but no mechanism exists to make payments over a communications channel without a trusted party.
- 中文: 互联网上的商业贸易几乎完全依赖于作为可信第三方的金融机构来处理电子支付。虽然该系统对于大多数交易已经足够有效，但它仍然受困于基于信任的模型固有的弱点。完全不可逆的交易实际上是不可能的，因为金融机构无法避免调解纠纷。调解成本增加了交易成本，限制了实际可行的最小交易规模，并切断了进行小额随意交易的可能性，而且更广泛的成本在于失去了为不可逆服务提供不可逆支付的能力。由于存在逆转的可能性，对信任的需求就扩散开了。商家必须提防他们的客户，纠缠他们索取本不需要的更多信息。一定比例的欺诈行为被认为是不可避免的。这些成本和支付的不确定性可以通过当面使用实物货币来避免，但不存在在没有可信方的情况下通过通信渠道进行支付的机制。
- English: What is needed is an electronic payment system based on cryptographic proof instead of trust, allowing any two willing parties to transact directly with each other without the need for a trusted third party. Transactions that are computationally impractical to reverse would protect sellers from fraud, and routine escrow mechanisms could easily be implemented to protect buyers. In this paper, we propose a solution to the double-spending problem using a peer-to-peer distributed timestamp server to generate computational proof of the chronological order of transactions. The system is secure as long as honest nodes collectively control more CPU power than any cooperating group of attacker nodes.
- 中文: 我们所需要的是一种基于密码学证明而非信任的电子支付系统，它允许任何有意愿的双方直接进行交易，而无需可信第三方。在计算上不可逆的交易将保护卖家免受欺诈，而常规的托管机制可以轻松实现以保护买家。在本文中，我们提出了一种解决双重支付问题的方案，即使用点对点分布式时间戳服务器来生成交易时间顺序的计算证明。只要诚实的节点共同控制的 CPU 算力超过任何合作攻击的节点组，该系统就是安全的。
- 简单解析：
现状吐槽： 现在的网上支付太依赖银行和信用卡公司了。交易能撤销，导致纠纷多、成本高，小额支付没法做。
新愿景： 我们要造一个基于数学密码的现金系统，让两个人可以直接交易，像给现金一样，不需要中间人。
2. 交易 (Transactions)
- English: We define an electronic coin as a chain of digital signatures. Each owner transfers the coin to the next by digitally signing a hash of the previous transaction and the public key of the next owner and adding these to the end of the coin. A payee can verify the signatures to verify the chain of ownership.
- 中文: 我们将一枚电子货币定义为一串数字签名链。每个所有者通过数字签名将前一笔交易的哈希和下一个所有者的公钥进行签名，并将这些签名添加到货币的末端，从而将货币转移给下一个所有者。收款人可以通过验证签名来验证所有权链。
- English: The problem of course is the payee can't verify that one of the owners did not double-spend the coin. A common solution is to introduce a trusted central authority, or mint, that checks every transaction for double spending. After each transaction, the coin must be returned to the mint to issue a new coin, and only coins issued directly from the mint are trusted not to be double-spent. The problem with this solution is that the fate of the entire money system depends on the company running the mint, with every transaction having to go through them, just like a bank.
- 中文: 当然，问题在于收款人无法验证所有者之一是否双重花费了这枚货币。一个常见的解决方案是引入一个可信的中央权威机构，或造币厂，来检查每笔交易是否存在双重支付。每次交易后，货币必须返回造币厂以发行新的货币，只有直接由造币厂发行的货币才被信任没有双重支付。这种解决方案的问题在于，整个货币系统的命运取决于运营造币厂的公司，每笔交易都必须经过它们，就像银行一样。
- English: We need a way for the payee to know that the previous owners did not sign any earlier transactions. For our purposes, the earliest transaction is the one that counts, so we don't care about later attempts to double-spend. The only way to confirm the absence of a transaction is to be aware of all transactions. In the mint based model, the mint was aware of all transactions and decided which arrived first. To accomplish this without a trusted party, transactions must be publicly announced [1], and we need a system for participants to agree on a single history of the order in which they were received. The payee needs proof that at the time of each transaction, the majority of nodes agreed it was the first received.
- 中文: 我们需要一种方法让收款人知道之前的所有者没有签署任何更早的交易。就我们的目的而言，最早的交易才是有效的，所以我们不关心之后的双重支付尝试。确认不存在某笔交易的唯一方法是了解所有交易。在基于造币厂的模型中，造币厂知晓所有交易并决定哪些交易先到达。为了在没有可信方的情况下实现这一点，交易必须被公开宣布 [1]，我们需要一个系统让参与者就它们被接收的顺序的单一历史达成一致。收款人需要证明在每笔交易发生时，大多数节点都同意它是第一个被接收到的。
- 简单解析：
电子钱的新定义： 比特币不是一枚“硬币”，而是一条所有权转移的记录链。比如：张三 -> 李四 -> 王五。每次转账都有数字签名，证明是本人操作。
核心难题： 怎么防止张三把同一笔钱同时转给李四和王五？传统方法是靠银行这个中心账本来判断先后。我们现在要想办法去中心化地解决这个问题。
3. 时间戳服务器 (Timestamp Server)
- English: The solution we propose begins with a timestamp server. A timestamp server works by taking a hash of a block of items to be timestamped and widely publishing the hash, such as in a newspaper or Usenet post [2-5]. The timestamp proves that the data must have existed at the time, obviously, in order to get into the hash. Each timestamp includes the previous timestamp in its hash, forming a chain, with each additional timestamp reinforcing the ones before it.
- 中文: 我们提出的解决方案始于一个时间戳服务器。时间戳服务器的工作原理是：获取要加盖时间戳的数据项的哈希值，并广泛公布该哈希值，例如发表在报纸或Usenet帖子上[2-5]。时间戳证明了数据显然必须在那个时间点存在，才能被纳入哈希中。每个时间戳在其哈希中都包含了前一个时间戳，从而形成一条链，每个新增的时间戳都强化了之前的时间戳。
- 简单解析：
想出的办法： 我们把一堆交易打包成一个“区块”，然后给这个区块盖上一个有时间顺序的“邮戳”（哈希值）。每个新邮戳都包含上一个邮戳的信息，这样就形成了一条链。想改以前的记录？所有后面的邮戳都得重盖。
4. 工作量证明 (Proof-of-Work)
- English: To implement a distributed timestamp server on a peer-to-peer basis, we will need to use a proof-of-work system similar to Adam Back's Hashcash [6], rather than newspaper or Usenet posts. The proof-of-work involves scanning for a value that when hashed, such as with SHA-256, the hash begins with a number of zero bits. The average work required is exponential in the number of zero bits required and can be verified by executing a single hash.
- 中文: 为了在点对点的基础上实现一个分布式时间戳服务器，我们需要使用一个类似于亚当·巴克的哈希现金（Hashcash）[6]的工作量证明系统，而不是报纸或Usenet帖子。工作量证明涉及寻找一个值，使得该值被哈希（例如用SHA-256算法）后，得到的哈希值以一定数量的零比特开始。所需平均工作量随所需零比特数的增加呈指数级增长，并且可以通过执行一次哈希运算来验证。
- English: For our timestamp network, we implement the proof-of-work by incrementing a nonce in the block until a value is found that gives the block's hash the required zero bits. Once the CPU effort has been expended to make it satisfy the proof-of-work, the block cannot be changed without redoing the work. As later blocks are chained after it, the work to change the block would include redoing all the blocks after it.
- 中文: 对于我们的时间戳网络，我们通过增加区块中的一个随机数（nonce）来实现工作量证明，直到找到一个值使得该区块的哈希值满足所需的零比特要求。一旦消耗了CPU算力使其满足工作量证明，该区块就无法被更改，除非重新完成工作量。随着后面的区块被链接到它之后，要更改该区块的工作量将包括重新完成它之后的所有区块的工作。
- English: The proof-of-work also solves the problem of determining representation in majority decision making. If the majority were based on one-IP-address-one-vote, it could be subverted by anyone able to allocate many IPs. Proof-of-work is essentially one-CPU-one-vote. The majority decision is represented by the longest chain, which has the greatest proof-of-work effort invested in it. If a majority of CPU power is controlled by honest nodes, the honest chain will grow the fastest and outpace any competing chains. To modify a past block, an attacker would have to redo the proof-of-work of the block and all blocks after it and then catch up with and surpass the work of the honest nodes. We will show later that the probability of a slower attacker catching up diminishes exponentially as subsequent blocks are added.
- 中文: 工作量证明也解决了在多数决策中确定代表权的问题。如果多数权是基于“一IP一票”，那么任何能够分配大量IP的人都可以破坏它。工作量证明本质上是“一CPU一票”。多数决策由最长的链代表，该链投入了最大的工作量证明。如果大多数CPU算力由诚实节点控制，诚实的链将增长最快，并超过任何竞争链。要修改一个过去的区块，攻击者必须重新完成该区块及所有后续区块的工作量证明，然后赶上并超过诚实节点的工作量。我们稍后将证明，随着后续区块的添加，较慢的攻击者赶上的概率会呈指数级下降。
- 简单解析：
如何实现？ 我们让“盖邮戳”（生成区块）这件事变得非常困难，需要电脑进行大量的计算（像解一道超级难的数学题）。这就是“工作量证明”。
一石二鸟：
- 防篡改：改旧账意味着要重做所有后面的数学题，成本太高。
- 投票权： 谁的算力强，谁在决定账本顺序时话语权就大（一CPU一票）。最长的链代表了最多算力的投入，就是大家公认的账本。
5. 网络 (Network)
- English:The steps to run the network are as follows:
- New transactions are broadcast to all nodes.
- Each node collects new transactions into a block.
- Each node works on finding a difficult proof-of-work for its block.
- When a node finds a proof-of-work, it broadcasts the block to all nodes.
- Nodes accept the block only if all transactions in it are valid and not already spent.
- Nodes express their acceptance of the block by working on creating the next block in the chain, using the hash of the accepted block as the previous hash.
- 中文:运行网络的步骤如下：
- 新交易向所有节点广播。
- 每个节点将新交易收集到一个区块中。
- 每个节点致力于为其区块寻找一个困难的工作量证明。
- 当一个节点找到了工作量证明，它就将该区块广播给所有节点。
- 仅当区块中的所有交易均有效且未被花费时，节点才接受该区块。
- 节点通过致力于创建链中的下一个区块来表达它们对已接受区块的认可，并使用已接受区块的哈希作为前一个哈希。
- English: Nodes always consider the longest chain to be the correct one and will keep working on extending it. If two nodes broadcast different versions of the next block simultaneously, some nodes may receive one first and the other later. In that case, they work on the first one they received, but save the other branch in case it becomes longer. The tie will be broken when the next proof-of-work is found and one branch becomes longer; the nodes that were working on the other branch will then switch to the longer one.
- 中文: 节点始终将最长的链视为正确的链，并持续努力扩展它。如果两个节点同时广播不同版本的下一个区块，有些节点可能先收到一个，后收到另一个。在这种情况下，它们会在先收到的那个区块上工作，但同时保存另一个分支，以防它变得更长。当找到下一个工作量证明并且一个分支变得更长时，这种平局就会被打破；之前在另一个分支上工作的节点将切换到更长的分支上。
- English: New transaction broadcasts do not necessarily need to reach all nodes. As long as they reach many nodes, they will get into a block before long. Block broadcasts are also tolerantof dropped messages. If a node does not receive a block, it will request it when it receives the next block and realizes it missed one.
- 中文: 新交易的广播不一定要到达所有节点。只要到达许多节点，它们不久就会被纳入一个区块。区块广播也能容忍消息丢失。如果一个节点没有收到某个区块，它会在收到下一个区块并意识到漏掉一个时去请求该缺失的区块。
- 简单解析：
运行步骤：
- 有人发起一笔交易，广播给所有人。
- “矿工”们收集交易，抢着做数学题（工作量证明）来打包新区块。
- 谁先解出题，就把他的新区块广播给全网。
- 大家验证区块里的交易没问题，就把它接到自己账本的最长链上，然后基于这个新区块继续抢答下一题。
简单说： 就是大家比赛记账，只认可最长的那个账本。
6. 激励 (Incentive)
- English:By convention, the first transaction in a block is a special transaction that starts a new coin owned by the creator of the block. This adds an incentive for nodes to support the network, and provides a way to initially distribute coins into circulation, since there is no central authority to issue them. The steady addition of a constant of amount of new coins is analogous to gold miners expending resources to add gold to circulation. In our case, it is CPU time and electricity that is expended.
- 中文:按照惯例，区块中的第一笔交易是一笔特殊的交易，它产生一枚新的货币，归属于该区块的创建者。这为节点支持网络增加了激励，并提供了一种将货币初始投放流通的方式，因为没有中央机构来发行它们。持续增加固定数量的新货币，类似于金矿工消耗资源将黄金投入流通。在我们的案例中，消耗的是CPU时间和电力。
- English: The incentive can also be funded with transaction fees. If the output value of a transaction is less than its input value, the difference is a transaction fee that is added to the incentive value of the block containing the transaction. Once a predetermined number of coins have entered circulation, the incentive can transition entirely to transaction fees and be completely inflation free.
- 中文: 激励也可以由交易费来资助。如果一笔交易的输出值小于其输入值，差额部分就是交易费，该费用被添加到包含这笔交易的区块的激励值中。一旦预定数量的货币进入流通，激励可以完全转变为交易费，从而完全避免通货膨胀。
- English: The incentive may help encourage nodes to stay honest. If a greedy attacker is able to assemble more CPU power than all the honest nodes, he would have to choose between using it to defraud people by stealing back his payments, or using it to generate new coins. He ought to find it more profitable to play by the rules, such rules that favour him with more new coins than everyone else combined, than to undermine the system and the validity of his own wealth.
- 中文: 激励可能有助于鼓励节点保持诚实。如果一个贪婪的攻击者能够聚集比所有诚实节点更多的CPU算力，他将不得不做出选择：是用它来通过偷回已付款项进行欺诈，还是用它来生成新货币。他应该会发现，遵守规则（这些规则让他获得比所有其他人加起来还多的新货币）比破坏系统及其自身财富的有效性更有利可图。
- 简单解析： 为啥有人愿意费电记账？
给奖励！ 成功打包新区块的矿工会得到两笔钱：
- 新区块奖励：系统凭空生成的新比特币（这是比特币的发行方式）。
- 交易手续费：转账人支付的小费。
这很关键： 奖励机制让大家都想当诚实的矿工，因为破坏规则反而会让自己手里的币贬值。
7. 回收硬盘空间 (Reclaiming Disk Space)
- English: Once the latest transaction in a coin is buried under enough blocks, the spent transactions before it can be discarded to save disk space. To facilitate this without breaking the block's hash, transactions are hashed in a Merkle Tree [7][2][5], with only the root included in the block's hash. Old blocks can then be compacted by stubbingoff branches of the tree. The interior hashes do not need to be stored.
- 中文: 一旦一枚货币中最新的交易被足够多的区块覆盖，它之前已被花费的交易就可以被丢弃以节省硬盘空间。为了在不破坏区块哈希的情况下实现这一点，交易被存储在梅克尔树（Merkle Tree）[7][2][5]中，只有树的根被包含在区块的哈希中。然后，可以通过截断树的枝干来压缩旧区块。内部的哈希不需要存储。
- English: A block header with no transactions would be about 80 bytes. If we assume blocks are generated every 10 minutes, 80 bytes * 6 * 24 * 365 = 4.2MB per year. With computer systems typically selling with 2GB of RAM as of 2008, and Moore's Law predicting current growth of 1.2GB per year, storage should not be a problem even if the block headers must be kept in memory.
- 中文: 一个不带交易数据的区块头大约为80字节。如果我们假设每10分钟产生一个区块，80字节 * 6 * 24 * 365 = 每年4.2MB。截至2008年，计算机系统通常配备2GB内存，而摩尔定律预测当前每年增长1.2GB，即使区块头必须保存在内存中，存储也不应该成为问题。
- 简单解析：
精简账本： 不用保存所有历史细节。我们用一种叫“默克尔树”的密码学方法，生成一个很短的“指纹”（根哈希）。只要这个指纹在，就能证明某笔交易的真实性。这样老旧的交易记录就可以压缩，节省空间。
8. 简化支付验证 (Simplified Payment Verification)
- English: It is possible to verify payments without running a full network node. A user only needs to keep a copy of the block headers of the longest proof-of-work chain, which he can get by querying network nodes until he's convinced he has the longest chain, and obtain the Merkle branch linking the transaction to the block it's timestamped in. He can't check the transaction for himself, but by linking it to a place in the chain, he can see that a network node has accepted it, and blocks added after it further confirm the network has accepted it.
- 中文: 在不运行完整网络节点的情况下验证支付是可能的。用户只需要保存最长工作量证明链的区块头副本，他可以通过查询网络节点直到确信自己拥有最长的链来获取这些区块头，并获取将该交易与它被打时间戳的区块连接起来的梅克尔分支。他无法自行验证该交易，但通过将其链接到链中的一个位置，他可以确认网络节点已经接受了它，而在其后添加的区块进一步确认网络已经接受了它。
- English: As such, the verification is reliable as long as honest nodes control the network, but is more vulnerable if the network is overpowered by an attacker. While network nodes can verify transactions for themselves, the simplified method can be fooled by an attacker's fabricated transactions as long as the attacker can continue to overpower the network. One strategy to protect against this is to accept alerts from network nodes when they detect an invalid block, prompting the user's software to download the full block and alerted transactions to confirm the inconsistency. Businesses that receive frequent payments will probably still want to run their own nodes for more independent security and quicker verification.
- 中文: 因此，只要诚实节点控制着网络，这种验证就是可靠的，但如果网络被攻击者压制，则更容易受到攻击。虽然网络节点可以自行验证交易，但只要攻击者能够持续压制网络，这种简化方法可能会被攻击者伪造的交易欺骗。防范这种攻击的一种策略是接受网络节点在检测到无效区块时发出的警报，提示用户的软件下载完整的区块和被警告的交易以确认不一致性。接收频繁付款的企业可能仍然希望运行自己的节点，以获得更独立的安全性和更快的验证速度。
- 简单解析：
轻钱包原理： 像手机钱包这种轻量级应用，不需要下载几百GB的完整账本。它只需要下载所有区块的“区块头”（很小），然后向全节点请求一个简单的证明，就能确认你的支付是否成功。虽然方便，但安全性略低于运行全节点。
9. 价值的组合与分割 (Combining and Splitting Value)
- English: Although it would be possible to handle coins individually, it would be unwieldy to make a separate transaction for every cent in a transfer. To allow value to be split and combined, transactions contain multiple inputs and outputs. Normally there will be either a single input from a larger previous transaction or multiple inputs combining smaller amounts, and at most two outputs: one for the payment, and one returning the change, if any, back to the sender.
- 中文: 虽然可以单独处理每一枚货币，但为转账中的每一分钱都进行一次单独的交易将非常不便。为了允许价值被分割和组合，交易包含多个输入和输出。通常，会有一个来自之前较大交易的单一输入，或者组合了较小金额的多个输入，以及最多两个输出：一个用于付款，另一个（如果有找零）将找零返回给发送方。
- English: It should be noted that fan-out, where a transaction depends on several transactions, and those transactions depend on many more, is not a problem here. There is never the need to extract a complete standalone copy of a transaction's history.
- 中文: 应该注意的是，这里不存在扇出（一个交易依赖于多个交易，而这些交易又依赖于更多交易）的问题。永远不需要提取一个交易历史的完整独立副本。
- 简单解析：
和现金一样： 交易可以有多笔输入和多笔输出。比如，你可以把三张10块钱（三个输入）合并起来，付给别人25块，同时给自己找零5块（两个输出）。非常灵活。
10. 隐私 (Privacy)
- English: The traditional banking model achieves a level of privacy by limiting access to information to the parties involved and the trusted third party. The necessity to announce all transactions publicly precludes this method, but privacy can still be maintained by breaking the flow of information in another place: by keeping public keys anonymous. The public can see that someone is sending an amount to someone else, but without information linking the transaction to anyone. This is similar to the level of information released by stock exchanges, where the time and size of individual trades, the "tape", is made public, but without telling who the parties were.
- 中文: 传统的银行模型通过将信息访问权限限制在相关方和可信第三方来实现一定程度的隐私。公开宣布所有交易的必要性排除了这种方法，但隐私仍然可以通过在另一个地方打破信息流来维护：保持公钥的匿名性。公众可以看到某人正在向另一个人发送一笔金额，但没有信息将该交易与任何人联系起来。这类似于证券交易所发布的信息级别，即单个交易的时间和大小（“磁带”）是公开的，但不告知交易方是谁。
- English: As an additional firewall, a new key pair should be used for each transaction to keep them from being linked to a common owner. Some linking is still unavoidable with multi-input transactions, which necessarily reveal that their inputs were owned by the same owner. The risk is that if the owner of a key is revealed, linking could reveal other transactions that belonged to the same owner.
- 中文: 作为额外的防火墙，每一笔交易都应使用一个新的密钥对，以防止它们被链接到同一个所有者。对于多输入交易，某些链接仍然是不可避免的，这必然会揭示它们的输入属于同一个所有者。风险在于，如果一个密钥的所有者被揭露，链接可能会揭示属于同一所有者的其他交易。
- 简单解析：
伪匿名： 交易记录完全公开，但上面只有你的钱包地址（像银行账号），没有你的真实姓名。每次交易都用新地址，能更好地保护隐私。这就像证券交易所公布交易量和时间，但不公布买卖双方是谁。
11. 计算 (Calculations)
- English:(此章节包含大量数学推导和概率计算，旨在证明攻击者追上诚实链的概率随着确认次数的增加而指数级下降，此处省略详细公式。)
- 中文:(此章节包含大量数学推导和概率计算，旨在证明攻击者追上诚实链的概率随着确认次数的增加而指数级下降，此处省略详细公式。)
12. 结论 (Conclusion)
- English: We have proposed a system for electronic transactions without relying on trust. We started with the usual framework of coins made from digital signatures, which provides strong control of ownership, but is incomplete without a way to prevent double-spending. To solve this, we proposed a peer-to-peer network using proof-of-work to record a public history of transactions that quickly becomes computationally impractical for an attacker to change if honest nodes control a majority of CPU power. The network is robust in its unstructured simplicity. Nodes work all at once with little coordination. They do not need to be identified, since messages are not routed to any particular place and only need to be delivered on a best effort basis. Nodes can leave and rejoin the network at will, accepting the proof-of-work chain as proof of what happened while they were gone. They vote with their CPU power, expressing their acceptance of valid blocks by working on extending them and rejecting invalid blocks by refusing to work on them. Any needed rules and incentives can be enforced with this consensus mechanism.
- 中文: 我们提出了一种不依赖于信任的电子交易系统。我们从由数字签名构成的货币的常规框架出发，该框架提供了强大的所有权控制，但如果没有防止双重支付的方法，它是不完整的。为了解决这个问题，我们提出了一个使用工作量证明的点对点网络，来记录公共的交易历史记录，如果诚实节点控制大多数CPU算力，该历史记录会迅速变得在计算上对攻击者而言不可更改。该网络以其非结构化的简洁性而健壮。节点同时工作，几乎不需要协调。它们不需要被识别，因为消息不会被路由到任何特定位置，只需要尽最大努力传递即可。节点可以随时离开和重新加入网络，接受工作量证明链作为它们离开期间所发生事件的证明。它们用自己的CPU算力进行投票，通过努力扩展有效区块来表示接受，并通过拒绝在无效区块上工作来表示拒绝。任何所需的规则和激励都可以通过这种共识机制来实施。
- 简单解析：
我们成功设计了一个无需信任的电子现金系统。它通过点对点网络、工作量证明和激励机制，完美地解决了双重支付问题。这个系统非常健壮，节点可以自由加入或离开，共同维护着账本的真实性。
一句话总结
比特币就是一个由全球用户共同维护的、通过竞争记账和耗电计算来保证安全的、公开的分布式电子现金账本。
参考文献 (References)
- [1] W. Dai, "b-money,"http://www.weidai.com/bmoney.txt, 1998.
- [2] H. Massias, X.S. Avila, and J.-J. Quisquater, "Design of a secure timestamping service with minimal trust requirements," In 20th Symposium on Information Theory in the Benelux, May 1999.
- [3] S. Haber, W.S. Stornetta, "How to time-stamp a digital document," In Journal of Cryptology, vol 3, no 2, pages 99-111, 1991.
- [4] D. Bayer, S. Haber, W.S. Stornetta, "Improving the efficiency and reliability of digital time-stamping," In Sequences II: Methods in Communication, Security and Computer Science, pages 329-334, 1993.
- [5] S. Haber, W.S. Stornetta, "Secure names for bit-strings," In Proceedings of the 4th ACM Conference on Computer and Communications Security, pages 28-35, April 1997.
- [6] A. Back, "Hashcash - a denial of service counter-measure,"http://www.hashcash.org/papers/hashcash.pdf, 2002.
- [7] R.C. Merkle, "Protocols for public key cryptosystems," In Proc. 1980 Symposium on Security and Privacy, IEEE Computer Society, pages 122-133, April 1980.
- [8] 中文参考文献名略，与英文对应。