The documentary Finding Satoshi proposes that bitcoin’s pseudonymous creator may have been two individuals collaborating on the project since its inception.

Film's claim

According to the filmmakers, Hal Finney handled software development and technical tasks, while Len Sassaman focused on texts, communication and ideological framing.

Evidence presented

The film points to overlaps in digital traces, their joint presence in cryptographic communities and irregularities in Satoshi’s activity patterns as supporting the hypothesis.

• Coincidences in online identifiers and timestamps that the film argues connect Finney’s and Sassaman’s public contributions with Satoshi-era postings.
• Both men were active on early cryptography mailing lists and projects, providing a social and technical environment conducive to cooperative authorship.
• Patterns of Satoshi’s online behavior are presented as more easily explained by two collaborators alternating operational and writing duties.

Implications

The documentary also notes Satoshi’s cessation of posts in 2011 and the later deaths of both candidates, suggesting a possible reason for dormant bitcoin balances.

The filmmakers frame these elements as circumstantial rather than conclusive and call for additional research and corroborating evidence to substantiate the dual-authorship theory.