Stuart Haber
Chief Cryptographic Officer, SureMark Digital
Stuart Haber, co-author with W. Scott Stornetta of the 1991 digital timestamping paper cited in the Bitcoin white paper, now works on cryptographic identity verification as Chief Cryptographic Officer of SureMark Digital.
Why the room needs them.
Stuart Haber co-wrote the 1991 timestamping paper cited in the Bitcoin white paper and is Chief Cryptographic Officer of SureMark Digital. He spoke at Proof of Talk Paris 2026 on a panel about personhood, provenance and verification in the agentic age.
The full account.
Stuart Haber is a cryptographer whose 1991 paper "How to Time-Stamp a Digital Document", written with W. Scott Stornetta and published in the Journal of Cryptology (vol. 3, no. 2, pp. 99–111), set out a method for certifying when a digital document was created. Satoshi Nakamoto's Bitcoin white paper lists that paper among its eight references, alongside two further papers Haber co-wrote with Stornetta.
Haber graduated magna cum laude from Harvard University in 1978 with a B.A. in mathematics and earned a PhD at Columbia University in 1987, the year he joined Bell Communications Research (Bellcore). Stornetta joined Bellcore in 1989, and the timestamping research grew out of their work there. In 1994 the two co-founded Surety Technologies as a Bellcore spin-off; SureMark Digital describes the time-stamping service they deployed in 1995 as the world's first commercial blockchain.
Haber joined HP Labs in 2002 and spent 15 years in its Princeton office working on cryptography and security problems. In 2018 he joined the blockchain platform Kadena as an advisor. SureMark Digital's biography of him says his career has spanned large companies, among them Hewlett Packard Enterprise, HP Labs and Bellcore, and start-ups including InterTrust and Surety.
According to a PR Newswire release dated 1 July 2026, Haber is Chief Cryptographic Officer of SureMark Digital, the company he and Stornetta founded, with Stornetta as chief executive. SureMark provides cryptographic identity verification; in September 2025 it announced a product for wealth-management firms intended to protect client-advisor conversations from AI-driven impersonation.
Haber spoke at Proof of Talk Paris 2026 as Chief Cryptographic Officer of SureMark Digital. On 3 June 2026, the summit's second day, he appeared on the Taostats Stage in the panel "Personhood, Provenance, and Verification in the Agentic Age", alongside Pierre Aubert, Evin McMullen and Chi Zhang, in a session moderated by Mohamed Ezeldin.
In a 2022 email interview with Forkast, given while he was speaking at the Singapore FinTech Festival, Haber said of the original work: "The idea behind the invention was not for specific use in financial systems."
What Stuart believes about the next ten years.
Years of shipping.
Lines that keep proving correct.
“The idea behind the invention was not for specific use in financial systems.”
“Curiosity is always the fuel for great innovations.”
What they have built, written, and backed.
Built
- "How to Time-Stamp a Digital Document" (1991)Paper with W. Scott Stornetta in the Journal of Cryptology, vol. 3, no. 2, pp. 99–111; listed as reference [3] in the Bitcoin white paper.
- Surety Technologies (1994)Co-founded with Stornetta as a Bellcore spin-off; SureMark Digital describes its 1995 time-stamping service as the world's first commercial blockchain.
- Digital time-stamping patentsUS Patent 5,136,647 ("Method for secure time-stamping of digital documents") and US Patent 5,136,646 ("Digital document time-stamping with catenate certificate"), both 1992, as listed on his Google Scholar profile.
- SureMark DigitalCryptographic identity-verification company founded by Haber and Stornetta, where Haber is Chief Cryptographic Officer; in September 2025 it announced a product to protect wealth-management client-advisor conversations from AI-driven impersonation.
The next Proof of Talk is in Abu Dhabi.
Louvre Abu Dhabi, 3–4 December 2026. Admission is by application, and the room is capped at 2,000.
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