Ray Dillinger

Before Bitcoin v0.1 was released to the public in January 2009, Satoshi’s source code reached three people on the record — Hal Finney, Ray Dillinger, and James A. Donald — and Finney and Dillinger are the two known to have reviewed it. Dillinger spent roughly two weeks examining the code for vulnerabilities and attack vectors — direct, named counter-context for Wei Dai’s 2011 remark that “not many other cryptographers” had analyzed Bitcoin’s security.

He has also described a role in the origin of Bitcoin’s 1 MB block size limit — a parameter that would later become the center of the 2015–2017 block-size war — though his account of when the limit was adopted conflicts with the documented commit history.

Dillinger is a computer scientist known by his online handles bear and cryddit. He studied computer science at the University of Kansas and has been active in the cryptography and cypherpunk communities for decades.

Pre-Release Code Review

In late 2008, Satoshi Nakamoto shared Bitcoin’s source code privately with a small number of people before the public release in January 2009. Dillinger conducted a security audit of the code, examining it for potential vulnerabilities and attack vectors. Hal Finney simultaneously reviewed the code from a different perspective. Finney’s November 19, 2008 reply had Dillinger and James A. Donald on Cc, under the subject “Re: Bitcoin source files attached”; Satoshi had told Donald on the cryptography list two days earlier, “I sent you the main files.” In a later BitcoinTalk post, Dillinger recalled spending approximately two weeks reviewing the code, focusing on ways the system might be exploited. In a 2018 interview marking the whitepaper’s tenth anniversary, he gave the technical substance of that review as he remembered it — the floating-point accounting he recalls finding and the satoshi-precision analysis.

Block Size Limit

In a February 2015 BitcoinTalk post, Dillinger described the origin of the 1 MB block size limit — one of the most debated parameters in Bitcoin’s history — as Hal Finney’s idea, prompted by Finney’s concern about a potential denial-of-service attack; Dillinger recalled that he and Satoshi both objected the cap would not scale, but all three agreed a temporary limit was needed. By Dillinger’s account, “the 1MB limit was there by the time Bitcoin launched” in January 2009.

That timing conflicts with the documented history: source-code and blockchain records show Satoshi added the 1 MB limit unilaterally, without announcement, in a July 2010 commit that took effect in September 2010 — roughly a year and a half after launch. See the block-size war overview for the documented origin of the limit and the dispute the limit later provoked. The discrepancy between Dillinger’s recollection and the commit-history record remains unresolved.

Mailing List Participation

Dillinger participated in the cryptography mailing list discussion about Bitcoin in November 2008, posting under the name “Ray Dillinger.” His posts engaged with the technical details of Bitcoin’s design, including questions about the incentive structure and security model — pronouncing the currency “unholdable” at the time, a first reaction that the record of what others said about Satoshi collects alongside his later, more admiring retrospectives.

Later Reflections

In September 2017, Dillinger published a reflective essay on LinkedIn, “If I’d Known What We Were Starting,” recalling his November 2008 review of the block chain code alongside Hal Finney. He wrote that Bitcoin’s lack of any Trusted role was the main thing that convinced him Satoshi wasn’t scamming, and turned on the altcoin and ICO launches that had since built the toll bridges Satoshi left out. The pre-release source code itself, which Dillinger posted on BitcoinTalk as “Cryddit” in December 2013, was taken apart in an October 2022 piece by security researcher SerHack, revealing a discarded September 2008 genesis block dated to the day of Lehman Brothers’ $3.9 billion loss report.