Adam Back says Bitcoin’s post-quantum shift may reveal true Satoshi stash

Blockstream CEO Adam Back said Thursday that a future post-quantum migration of Bitcoin could help clarify how many coins linked to Satoshi Nakamoto remain accessible, because any owner wanting to protect vulnerable holdings would need to move them to a new address format.

Speaking at Paris Blockchain Week, Back said such a migration would likely give users ample time to move funds and argued that coins left unmoved after that process could reasonably be treated as lost.

“This migration to post-quantum address format may tell us how many of those coins [Satoshi] still has,” said Back, adding that the pseudonymous creator has an estimated 500,000 to 1 million Bitcoin (BTC).

Satoshi’s Bitcoin stash has ignited heated debate among Bitcoin holders concerned by the quantum computing threat. On Wednesday, Jameson Lopp and five co-authors published a Bitcoin Improvement Proposal aimed at restricting the future movement of coins held in quantum-vulnerable address formats, including older coins whose public keys have already been exposed.

Adam Back, keynote speech at Paris Blockchain Week in 2026. Source: Cointelegraph

Blockchain data platform Arkham estimates that Nakamoto-linked wallets hold 1.09 million Bitcoin, currently valued at $81.6 billion.

Related: Bernstein says Bitcoin market already priced in quantum risk

Back sees long runway on quantum

Back said Bitcoin developers and holders still have substantial time to prepare, arguing that a quantum breakthrough capable of threatening Bitcoin signatures is at least 20 years away.