Dai Wei，也許他的中文名是 “戴偉”。 他是華人，也是密碼朋克小組中，我們所知道的唯一華人。在比特幣之前，他提出的 B-Money 概念，實際上就是比特幣的原型。而中本聰與其溝通的三封郵件中，明確指出自己發明的比特幣 “實現了戴偉的 B-Money 概念”。
第一封郵件：中本聰至 Dai Wei
From: "Satoshi Nakamoto"
Sent: Friday, August 22, 2008 4:38 PM
To: "Wei Dai"
Cc: "Satoshi Nakamoto"
Subject: Citation of your b-money pageI was very interested to read your b-money page.? I'm getting ready to release a paper that expands on your ideas into a complete working system. Adam Back (hashcash.org) noticed the similarities and pointed me to your site.
I need to find out the year of publication of your b-money page for the citation in my paper.? It'll look like: [1] W. Dai, "b-money," http://www.weidai.com/bmoney.txt, (2006?).
You can download a pre-release draft at http://www.upload.ae/file/6157/ecash-pdf.html? Feel free to forward it to anyone else you think would be interested.
Title: Electronic Cash Without a Trusted Third Party
Abstract: A purely peer-to-peer version of electronic cash would allow online payments to be sent directly from one party to another without the burdens of going through a financial institution.? Digital signatures offer part of the solution, but the main benefits are lost if a trusted 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 honest nodes control the most CPU power on the network, they can generate the longest chain and outpace any attackers.? The network itself requires minimal structure.? Messages are broadcasted 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.
Satoshi
中本聰給 Dai Wei 郵件的譯文：
我讀了您介紹 b-money 的網頁，非常感興趣。 我很快就會發出一篇論文，能把您的思路，擴展成一個完整的，可運行的系統。 是 Adam Back (hashcash.org) 發現了兩者之間的相似之處，也是他讓我來看您的網站。
為了在我的論文中引用您的 b-money 概念，我需要確認您的 b-money 網頁的發布日期。 我的引用會是這樣：[1] W. Dai, "b-money," http://www.weidai.com/bmoney.txt, (2006?).
您從?http://www.upload.ae/file/6157/ecash-pdf.html 這個地址可以下載一份論文初稿。如果您覺得有人會感興趣，也請轉發。
標題：無需可信第三方的電子貨幣
摘要：一個徹底實現點對點的電子貨幣系統，可以在網絡上從一方直接支付到另一方，完全無需依賴金融機構。電子簽名解決了部分問題，但如果為了防備?“雙花”問題，依然還需要引入一個可信第三方的話，那就失去了點對點的主要優勢。我們設計了一個方案，在點對點網絡中，可以解決 “雙花” 問題。在此網絡上，通過對交易進行哈希運算，為交易打上時間戳，并勾連成鏈，且以哈希運算來證明創建鏈的工作量。這樣就形成了一條記錄，該記錄是無法篡改的，除非重算所有工作量證明。最長的鏈，不僅見證了事件發生的順序，也代表了它來自最大的 CPU 算力池。只要誠實的節點控制了網絡中大部分的 CPU 算力，則它們就能夠生成最長的鏈條，并把攻擊者拋在后面。此網絡本身只需要最小的結構 。消息以最佳的效果傳播，節點可以隨意離開，也可以隨意重新加入網絡，加入時接受工作量證明最長的鏈，認可那是它們離開網絡期間所發生事件的見證。
中本聰
第二封郵件：Dai Wei?至中本聰
Hi Satoshi. b-money was announced on the cypherpunks mailing list in 1998.
Here's the archived post:
http://cypherpunks.venona.com/date/1998/11/msg00941.htmlThere are some discussions of it at http://cypherpunks.venona.com/date/1998/12/msg00194.html.
Thanks for letting me know about your paper. I'll take a look at it and let you know if I have any comments or questions.
Dai Wei 給中本聰郵件的譯文：
Hi 中本聰：
b-money 是 1998 年在密碼朋克郵件組中發表的。
下面是歸檔的帖子:
http://cypherpunks.venona.com/date/1998/11/msg00941.html
這里您還能找到一些關于 b-money 的討論：
http://cypherpunks.venona.com/date/1998/12/msg00194.html.
謝謝告知您的論文。我會讀一下，如果我有意見和問題，我會聯系您。
第三封郵件：中本聰至 Dai Wei
From: Satoshi Nakamoto
Sent: Saturday, January 10, 2009 11:17 AM
To: weidai@weidai.comSubject: Re: Citation of your b-money page
I wanted to let you know, I just released the full implementation of the paper I sent you a few months ago, Bitcoin v0.1.? Details, download and screenshots are at www.bitcoin.org I think it achieves nearly all the goals you set out to solve in your
b-money paper.
The system is entirely decentralized, without any server or trusted parties.? The network infrastructure can support a full range of escrow transactions and contracts, but for now the focus is on the basics of money and transactions.
There was a discussion of the design on the Cryptography mailing list.
Hal Finney gave a good high-level overview:
| One thing I might mention is that in many ways bitcoin is two independent
| ideas: a way of solving the kinds of problems James lists here, of
| creating a globally consistent but decentralized database; and then using
| it for a system similar to Wei Dai's b-money (which is referenced in the
| paper) but transaction/coin based rather than account based. Solving the
| global, massively decentralized database problem is arguably the harder
| part, as James emphasizes. The use of proof-of-work as a tool for this
| purpose is a novel idea well worth further review IMO.Satoshi
中本聰給 Dai Wei 郵件的譯文：
From: Satoshi Nakamoto
Sent: Saturday, January 10, 2009 11:17 AM
To: weidai@weidai.com
Subject: Re: Citation of your b-money page我特為告知您，我剛剛發布了比特幣 v0.1 版，這個系統完全實現了幾個月前我發給您的論文中的思想。從?www.bitcoin.org 您可以獲得詳細信息，也可以下載軟件和屏幕截圖。
我想，您在 b-money 論文中想要解決的問題，比特幣幾乎都做到了。
系統完全是去中心化的，無需任何服務器，也無需任何可信方。此網絡的架構，能夠支持各種托管交易和合約類型，但當前還只是實現了貨幣和交易的功能。
在密碼學郵件組中，有一個圍繞設計的討論。
哈爾芬尼作出的一個概括評價，非常好：“我想提的一點是，比特幣從各種角度看，都是兩個獨立的創意：首先是解決了 James 列出的那些問題，創造出一個實現了全局一致，但又去中心化的數據庫；然后用來實現了與 Wei Dai 的 b-money 非常類似的系統，但卻又不是基于賬戶的，而是基于交易/現金的。 James 就曾強調過，實現全局一致，但又大規模的去中心化數據庫，毫無疑問是最困難的部分。利用工作量證明的方法，來解決這個問題，是個天才的主意，非常值得進一步的認真思考。”
中本聰
