SN-0001 已核对来源，附原文与上下文。
我开发了一个新的开源 P2P 电子现金系统，叫 Bitcoin。它完全去中心化，没有中央服务器，也不需要可信第三方，因为一切都建立在密码学证明而不是信任上。欢迎试用，也可以先看看截图和设计论文：
I've developed a new open source P2P e-cash system called Bitcoin. It's completely decentralized, with no central server or trusted parties, because everything is based on crypto proof instead of trust. Give it a try, or take a look at the screenshots and design paper:
在 http://www.bitcoin.org 下载 Bitcoin v0.1
Download Bitcoin v0.1 at http://www.bitcoin.org
传统货币的根本问题，是它需要太多信任才能运作。我们必须相信中央银行不会让货币贬值，但法定货币的历史充满了对这种信任的背叛。我们必须相信银行能替我们保管资金并完成电子转账，可它们只保留很少的准备金，却一轮又一轮地放出信贷、吹大泡沫。我们还得把隐私交给银行，相信它们不会让身份窃贼冒用我们的身份、掏空账户。银行庞大的运营成本也让微支付无法实现。
The root problem with conventional currency is all the trust that's required to make it work. The central bank must be trusted not to debase the currency, but the history of fiat currencies is full of breaches of that trust. Banks must be trusted to hold our money and transfer it electronically, but they lend it out in waves of credit bubbles with barely a fraction in reserve. We have to trust them with our privacy, trust them not to let identity thieves drain our accounts. Their massive overhead costs make micropayments impossible.
上一代的多用户分时计算机系统也遇到过类似问题。在强加密技术出现之前，用户只能靠密码保护文件，把隐私寄托在系统管理员身上。管理员随时可以凭自己的判断推翻隐私原则，也可能按照上级要求这么做。后来强加密技术走向大众，人们不再需要这种信任。数据可以得到真正可靠的保护：无论别人有什么理由、借口多么充分，都无法从物理上访问它。
A generation ago, multi-user time-sharing computer systems had a similar problem. Before strong encryption, users had to rely on password protection to secure their files, placing trust in the system administrator to keep their information private. Privacy could always be overridden by the admin based on his judgment call weighing the principle of privacy against other concerns, or at the behest of his superiors. Then strong encryption became available to the masses, and trust was no longer required. Data could be secured in a way that was physically impossible for others to access, no matter for what reason, no matter how good the excuse, no matter what.
现在，货币也该有同样的保护了。电子货币可以建立在密码学证明上，不必信任第三方中介，让资金更安全、交易更轻松。
It's time we had the same thing for money. With e-currency based on cryptographic proof, without the need to trust a third party middleman, money can be secure and transactions effortless.
数字签名是这类系统的基础组成部分之一。一个数字货币单元包含所有者的公钥。转账时，所有者把这个币和下一位所有者的公钥放在一起签名。任何人都可以检查这些签名，验证所有权链。这样能很好地保护所有权，却还有一个大问题没有解决：双重支出，也就是把同一笔钱花两次。任何所有者都可以把已经花掉的币再次签给另一个人，试图重复花费。通常的做法，是让一家可信公司通过中央数据库检查双重支出，但这又回到了信任模型。这家公司处在系统中心，有权推翻用户的决定；维持公司运作所需的费用，也会让微支付变得不切实际。
One of the fundamental building blocks for such a system is digital signatures. A digital coin contains the public key of its owner. To transfer it, the owner signs the coin together with the public key of the next owner. Anyone can check the signatures to verify the chain of ownership. It works well to secure ownership, but leaves one big problem unsolved: double-spending. Any owner could try to re-spend an already spent coin by signing it again to another owner. The usual solution is for a trusted company with a central database to check for double-spending, but that just gets back to the trust model. In its central position, the company can override the users, and the fees needed to support the company make micropayments impractical.
Bitcoin 的解决办法，是让点对点网络检查双重支出。简单说，这个网络就像一台分布式时间戳服务器，为第一次花费某个币的交易盖上时间戳。它利用了信息容易传播、却很难被封锁的特点。工作原理详见设计论文：http://www.bitcoin.org/bitcoin.pdf
Bitcoin's solution is to use a peer-to-peer network to check for double-spending. In a nutshell, the network works like a distributed timestamp server, stamping the first transaction to spend a coin. It takes advantage of the nature of information being easy to spread but hard to stifle. For details on how it works, see the design paper at http://www.bitcoin.org/bitcoin.pdf
最终得到的是一个没有单点故障的分布式系统。用户自己掌握资金的密码学密钥，彼此直接交易，由 P2P 网络帮助检查双重支出。
The result is a distributed system with no single point of failure. Users hold the crypto keys to their own money and transact directly with each other, with the help of the P2P network to check for double-spending.
Satoshi Nakamoto
Satoshi Nakamoto
