Quantum Migration Could Unmask Satoshi Nakamoto’s Bitcoin Holdings

Speaking at Paris Blockchain Week, Blockstream CEO Adam Back outlined how a mandatory migration to post-quantum address formats could provide a definitive count of the Bitcoin held by the network's pseudonymous creator, Satoshi Nakamoto. Because protecting vulnerable holdings would require moving them to a new address format, the migration would effectively act as a census of active assets. The potential shift is driven by the long-term threat of quantum computing, which could eventually compromise current cryptographic standards such as the Elliptic Curve Digital Signature Algorithm (ECDSA) and Schnorr signatures. Back argued that coins left unmoved after such a migration process could reasonably be treated as lost. Current estimates of Satoshi's holdings vary. Back cited a range between 500,000 and 1 million BTC, while blockchain data platform Arkham estimates Nakamoto-linked wallets hold approximately 1.09 million BTC, currently valued at $81.6 billion. Despite the theoretical risk, Back emphasized that a quantum breakthrough capable of threatening Bitcoin signatures is likely at least two decades away. He characterized current quantum hardware as significantly underpowered, suggesting that developers and users have ample time to implement the hash-based signature schemes proposed by Blockstream Research in December 2025. This proposed security framework would rely on hash function assumptions, similar to existing Bitcoin network designs, providing a promising path for securing the network in a post-quantum environment.