Creator of b-money and Crypto++, cited in the Bitcoin white paper
![A faceless hooded silhouette between a cited document marked "[1]" and a sealed 2008 outreach envelope, with a small open-source code block feeding into a Bitcoin block icon](/images/analysis/webp/2008-08-22-wei-dai-biography-hero-1600.webp)
In November 1998, Wei Dai published b-money — a proposal for distributed digital cash — on the cypherpunks mailing list. Ten years later, on August 22, 2008, one day after learning of b-money for the first time through Adam Back’s referral, Satoshi Nakamoto emailed Dai directly:
I 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.
Two months later, the Bitcoin whitepaper cited b-money as reference [1].
Bitcoin v0.1 also shipped with Dai’s Crypto++ library for its SHA-256 implementation, making Dai’s code a direct dependency of Bitcoin from the first release.
In March 2014, asked on LessWrong whether Satoshi might be a known figure from the cryptography or cypherpunk communities, Dai answered:
My guess is that he’s not anyone who was previously active in the academic cryptography or cypherpunks communities, because otherwise he probably would have been identified by now based on his writing and coding styles.
Wei Dai is a computer scientist and cryptographer who studied at the University of Washington and worked at Microsoft.
The combination of b-money as whitepaper reference [1], the Crypto++ codebase dependency, and Satoshi’s pre-launch outreach has made Dai a recurring Satoshi-identity candidate — examined in a dedicated identity-hypothesis entry. The retrospective above is treated as the principal self-denial. Wired’s own November 2011 feature on Bitcoin’s rise and fall quoted Dai calling it “very significant” , and later in the same article listed him among the people some bitcoiners suspected of being Satoshi, along with his denial.
The smallest denomination in the Ethereum cryptocurrency, “wei,” is named after him.
In November 1998, Dai published “b-money”, a proposal for an anonymous, distributed electronic cash system, on the cypherpunks mailing list. The b-money proposal described a system where participants could create money by broadcasting the solution to a computational puzzle — much like Bitcoin’s later proof-of-work mining. The paper outlined two protocols: one requiring a synchronous broadcast channel, and another using a set of servers to keep track of balances. B-money was never implemented. Bitcoin’s whitepaper cites it as reference [1], added after Satoshi had completed his own design independently of it.
Dai also wrote and maintained Crypto++, an open-source C++ cryptography library — a project he was actively coding on the cypherpunks list as early as 1996, when he announced Disperse/Collect built from it. Bitcoin leaned on it from the start: the v0.1.0 source of January 2009 carries src/sha.cpp and src/sha.h with a header note that the routines were “extracted as a standalone file from Crypto++ Version 5.5.2 (9/24/2007)” — the latest Crypto++ release available when Bitcoin was being designed (mid-2007 onward).
The Crypto++ 5.6.0 SSE2-assembly-optimized SHA-256 was integrated into Bitcoin in version 0.3.6 (July 29, 2010 release). Primary-source timeline:
Dai’s connection to Bitcoin is twofold: b-money, cited in the whitepaper after the fact, and Crypto++, a direct codebase dependency from the earliest released version.
One day after emailing Adam Back to verify a Hashcash citation, Satoshi learned of b-money for the first time: Back’s reply on August 21, 2008 pointed him to Dai’s proposal, and Satoshi’s own response — “Thanks, I wasn’t aware of the b-money page, but my ideas start from exactly that point” — is the primary-source record that the design had been built independently of it. The next day, Satoshi emailed Dai directly, describing the paper he was about to release as one that “expands on your ideas” — the courtesy of a new citation rather than an acknowledged design debt — and asking for the year of b-money’s publication to cite it properly. The white paper, published on October 31, 2008, cites b-money as its first reference.
That August 22 email had also linked to the pre-release draft paper. Dai’s reply confirmed b-money’s 1998 posting date and archive links and said only that he would “take a look at it and let you know if I have any comments or questions” — comments that, by Dai’s own later account, never came. In an April 2013 LessWrong comment, Dai called this partly his own fault: “when Satoshi wrote to me asking for comments on his draft paper, I never got back to him. Otherwise perhaps I could have dissuaded him… from the ‘fixed supply of money’ idea.” In a 2014 post, Dai added that he had separately ignored Satoshi’s early-2009 email announcing the Bitcoin v0.1 release itself, the full implementation of “the paper I sent you a few months ago,” distracted at the time by LessWrong rather than Cypherpunks — not beginning to mine until 2011, an entry point he later clarified in a LessWrong thread by stating plainly that he did not create Bitcoin.
Dai’s 2014 retrospective and Satoshi’s own August 21, 2008 b-money disclaimer to Adam Back are two independent observations converging on the same picture of where Satoshi stood relative to the cypherpunk community during development, examined further in the cypherpunk independent-arrival analysis.
47 entries / 2 threads
On August 20, 2008 Satoshi emailed Adam Back a link to a draft titled "Electronic Cash Without a Trusted Third Party." Its title and abstract survive in two emails. The PDF does not.
Gwern lists where he looked for the draft Satoshi linked in August 2008: the file host, the Internet Archive, Google, BitcoinTalk, SVN. Dai, Back and Maxwell had no copy; Finney never replied.
On August 20, 2008 Satoshi called his C++ code nearly finished. Which precursors were in front of him by then? The earliest record for Hashcash, b-money, MicroMint, Bit Gold, DigiCash and RPOW.
Asked to change Bitcoin's rules, Dai explains that he did not create Bitcoin, that Satoshi reinvented the idea without reading his article, and that he has started mining with a Radeon 5870.
Dai judges that Bitcoin failed on monetary policy and adds that it may partly be his fault: when Satoshi asked for comments on his draft paper, he never got back to him.
Asked by author Dominic Frisby, Dai says he never coded b-money: the design was incomplete, he had grown disillusioned with cryptoanarchy, and he did not foresee such a system drawing wide use.
How a 1992 Oakland meeting became the Cypherpunks mailing list: the name, the remailers, the Clipper fight, the 1997 split, and the Hashcash and b-money posts the Bitcoin whitepaper later cited.
Wei Dai called Bitcoin's fixed supply a failure in 2013. His own 1998 b-money design needed the same real-world value figure Satoshi said software has no way to know.
A curated way in: questions about Satoshi Nakamoto and Bitcoin history, each pointing to the page that answers it in full.
Doubters called it unscalable in 2008. A famed hacker failed to break the code. A judge, a dictionary, and a Nobel nominator weighed in. What others said about Satoshi, read as one record.
The whitepaper's title names a payment system; section 6's gold is an analogy for issuance. Bitcoin is scarce like gold and spends like cash, and its scarcity later earned it the name digital gold.
Wei Dai announces b-money on the Cypherpunks list as a brief addendum to PipeNet 1.1, pointing readers to his eskimo.com page — the proposal later cited as reference [1] in the Bitcoin whitepaper.
Adam Back reposts the full text of Wei Dai's b-money proposal to the Cypherpunks list, with comments to follow — the message that opened the December 1998 b-money design discussion.
Hayek's 1976 case for competing currencies, the Extropians' imaginary 'Hayeks' currency of 1995, and Bitcoin, money no state issues: one line of thought, linked by ideas rather than proven influence.
Finding Satoshi (Tooley / Miele, April 2026) names Hal Finney and Len Sassaman as Bitcoin co-creators: Finney coded, Sassaman wrote the paper. Lopp and Back dispute it.
Bitcoin chose a hard 21M cap; b-money (1998) proposed elastic supply; fiat runs central-bank discretion. The cypherpunk debate, Wei Dai's 2013 regret, and 15 years of cryptocurrency variants.
Satoshi coded Bitcoin on Windows for 27 months, mainly with MinGW. In November 2009 he finished the Linux build Martti Malmi had started; by mid-2010 there were Windows, Linux and Mac releases.
What Satoshi's design assumed about a fee-only future, and the documented debate over whether transaction fees alone can sustain proof-of-work security after the block subsidy ends around 2140.
On November 21, 2011, Bitcoin v0.5 shipped with the Crypto++ SHA-256 subset removed and replaced by OpenSSL. Wei Dai's library, a direct codebase dependency since v0.1, was gone.
Wei Dai's b-money is whitepaper reference [1], his Crypto++ shipped inside Bitcoin v0.1, and he was the second person Satoshi contacted. The evidence for Wei Dai as Satoshi, weighed.
He built RPOW, received the first Bitcoin transaction, and lived blocks from Dorian Satoshi Nakamoto. The evidence for Hal Finney as Satoshi, weighed.
A reanalysis of van Dorst's stylometric corpus for the five most-cited candidates. Szabo led them, in the top 4.67% of 12,739 authors, but 594 unnamed authors came closer.
On May 15, 2015, the New York Times published Nathaniel Popper's Decoding the Enigma of Satoshi Nakamoto — a Digital Gold excerpt naming Bit Gold designer Nick Szabo as Satoshi. Szabo denied it.
He conceived Bit Gold, and three of the four most-cited stylometric studies place him first. The evidence for Nick Szabo as Satoshi, weighed.
Adam Back replies to Wei Dai on Cypherpunks, identifying seven monetary-design issues in b-money and proposing Hashcash as the minting mechanism — a substantive analysis ten years before Bitcoin.
Bitcoin v0.1 reuses one cypherpunk primitive (PoW from Hashcash), borrows general CS components (Merkle trees, linked timestamping, ECDSA), and synthesizes the rest (UTXO, mining, 21M cap, P2P).
Hashcash's inventor and the first person Satoshi contacted. In April 2026 the NYT named him the closest stylometric match among 620 cryptography-mailing-list writers. The evidence, weighed.
Satoshi has been hunted in public for years and left a large trail of material, yet remains unidentified. Why all that searching and all that material have not led to a name.
A reply that read like the continuation of Satoshi's thought — and two days later, Satoshi went silent. The evidence for HBO's Peter Todd identification, weighed.
Twelve recurring Satoshi candidates, compared across four independent layers: profile match, stylometric attribution, direct correspondence and development environment.
Three primary-source clues to Satoshi's place among the cypherpunks: he had not heard of b-money, Wei Dai called him "not previously active," and what Satoshi did tracked Hughes's 1993 manifesto.
Benjamin Wallace's Wired feature — an early major mainstream article on Bitcoin. Traces the whitepaper, mining boom, Mt. Gox hack, and growing pains, ending with Garzik's "We really don't care."
Wei Dai announces Disperse/Collect 1.0 on the Cypherpunks list and says he built it with his own Crypto++ library, a sign that he wrote code himself.
Wei Dai announces b-money on the Cypherpunks list as a secondary item alongside PipeNet 1.1, his primary focus. The proposal later cited in Bitcoin appears in a single sentence at the end of the post.
On LessWrong, Wei Dai clarifies he did not create Bitcoin — "only described a similar idea more than a decade ago" — buys a Radeon 5870 to mine, and warns Bitcoin lacks cryptographer security review.
In a LessWrong post, Wei Dai revealed that Satoshi had emailed him about Bitcoin v0.1 in early 2009, but that he ignored it because he was more interested in LessWrong than Cypherpunks at the time.
Wei Dai replies to Adam Back on Cypherpunks, conceding b-money would be at most a niche mechanism and revealing his shift toward viewing the government monopoly of force as a net benefit.
In LessWrong comments, Wei Dai argued Bitcoin's monetary policy had failed due to volatility, and regretted never commenting on Satoshi's 2008 draft: he might have talked him out of the fixed supply.
Wei Dai's March 2014 LessWrong Q&A: why he never built b-money, his disillusionment with crypto-anarchy, and his reading of Satoshi's motives and background.
Adam Back reflects on his August 2008 email exchange with Satoshi, his regret at not reading the whitepaper carefully, and his testimony in COPA v Wright, where the full email thread became public.
Nick Szabo's May 2011 blog post on why digital cash took eleven years to get from bit gold (1998) to Bitcoin (2009). It names libtech as the private list where bit gold and b-money grew in parallel.
Satoshi emails Wei Dai asking for the correct b-money citation, revealing he learned of it via Adam Back. The email linked the pre-release draft 'Electronic Cash Without a Trusted Third Party'.