Finney builds the first working proof-of-work token system, rooted in an IBM tamper-proof chip

AUG 15 2004 · 12:00

Video: Hal Finneys 2004 Reusable proof of works | How to mine it and what it teaches us. Date: 2004-08-15 · Type: primitive · Hub: bay-area · Tags: hal-finney, RPOW, proof-of-work, IBM-4758, blind-signatures, 2004, ALS, alcor RPOW was never widely adopted. It was the first time the loop ran in software anyone could run. Hal Finney — PGP 2.0 contributor, second cypherpunk in nearly every photograph from the early 1990s, future recipient of the first non-Satoshi Bitcoin transaction — announced RPOW on the metzdowd.com cryptography mailing list on 15 August 2004. The system accepted Hashcash tokens as proof-of-work, then minted RSA-blind-signed tokens that could be transferred and re-exchanged without double-spending. The trust root was an IBM 4758 cryptographic coprocessor: a tamper-resistant hardware security module running remotely attestable code, so that any user anywhere in the world could verify, cryptographically, exactly which software was producing the tokens. The hardware attestation was the distinctive move. Szabo's Bit Gold and Dai's b-money had described what a proof-of-work token system should look like; Finney built it, and he built it with a trust architecture that anticipated the hardware-based attestation questions that would recur in trusted-execution-environment discussions a decade later. RPOW didn't achieve adoption — the IBM 4758 was expensive, the user base was thin, and the token had no monetary anchor — but it demonstrated that the loop from computation to transferable value was closable in software. Finney received his ALS diagnosis in 2009, the same year Bitcoin launched, and he continued contributing to the Bitcoin codebase from a wheelchair-mounted eye-tracking interface until his physical capacity failed. He died in August 2014; his body was cryopreserved by the Alcor Foundation in Scottsdale, Arizona, per his prior arrangement. The first Bitcoin transaction — 10 BTC from Satoshi in block 170, 12 January 2009 — was sent to Finney. That the man who built the closest predecessor to Bitcoin received the first coins is either a beautiful coincidence or, if Szabo-is-Satoshi theories are correct, a more complicated gesture. Facts • Announced 15 August 2004, metzdowd.com cryptography mailing list • Tokens: RSA-blind-signed; underlying proof-of-work was Adam Back's Hashcash • Server platform: IBM 4758 secure cryptographic coprocessor (FIPS 140-1 Level 4 certified) • Finney (1956–2014) received ALS diagnosis 2009; continued contributing to Bitcoin by eye-tracking interface • Received 10 BTC from Satoshi Nakamoto in block 170, 12 January 2009 — first non-Satoshi Bitcoin transaction Primary Documents • RPOW — Reusable Proofs of Work — Satoshi Nakamoto Institute — https://nakamotoinstitute.org/finney/rpow/ • Original 15 Aug 2004 cryptography list announcement — https://www.metzdowd.com/pipermail/cryptography/2004-August/007362.html