New Quantum Proposal Offers Satoshi a Way to Prove Control Over Bitcoin Without Transferring Funds

Concerns over quantum computing have long plagued Bitcoin, with a particular issue at its core. Millions of bitcoins, including the approximately 1.1 million attributed to Satoshi Nakamoto, currently valued at around $84 billion, are stored in old wallets with exposed public keys, making them susceptible to theft by powerful quantum computers. The obvious solution is a soft fork that would eventually stop allowing transactions from these legacy addresses, forcing holders to move to quantum-safe formats before attackers can derive their private keys. However, this proposal, such as the one put forth by Jameson Lopp and other developers through BIP-361, which would phase out quantum-vulnerable addresses over a five-year timeline and freeze any coins that fail to migrate, creates a different problem. Long-dormant holders like Satoshi would have to publicly move their assets or risk losing access to them. Dan Robinson, a general partner at Paradigm, has proposed a solution that involves Provable Address-Control Timestamps, or PACTs, which allow holders to generate a proof of ownership at a specific date without revealing any information publicly until they need to spend their coins. This is achieved by creating a random salt and using BIP-322 to produce a proof of ownership, which is then bundled with the salt and timestamped through OpenTimestamps. If Bitcoin activates a soft fork that freezes quantum-vulnerable coins, the protocol could include a rescue path that accepts a STARK proof, showing the holder created their commitment before quantum hardware existed. This solution also addresses a gap in BIP-361 by including a rescue path for wallets derived through BIP-32. However, the implementation of PACTs requires Bitcoin to adopt a STARK verification protocol, which would need a separate soft fork with broad community consensus. Ultimately, PACTs offer a way to make the BIP-361 debate less binary, providing a choice between protecting against quantum theft and respecting dormant property rights, but the question remains whether Satoshi will utilize this solution.