New Bitcoin Proposal Offers Solution for Proving Control Without Moving Funds

Concerns over quantum computing have long been a challenge for Bitcoin, particularly for the millions of coins held in old wallets with exposed public keys, including those attributed to the cryptocurrency's creator, Satoshi Nakamoto. A proposed soft fork, or upgrade to existing network rules, could eventually stop allowing transactions from these legacy address types, forcing holders to move to quantum-safe formats. However, this would require long-dormant holders, including Satoshi, to publicly move their assets or risk losing access. To address this issue, Dan Robinson from Paradigm has proposed a concept called Provable Address-Control Timestamps, or PACTs, which enables holders to generate a proof of ownership and timestamp it without revealing any information publicly. This proof can be used to rescue coins if Bitcoin activates a soft fork that freezes quantum-vulnerable coins. The process involves generating a random salt and using a standard for signing messages from a Bitcoin address without spending from it to produce a proof of ownership. The salt and proof are then bundled together and timestamped through a free service, with the files remaining private. If a soft fork is activated, the protocol could include a rescue path that accepts a zero-knowledge proof, showing the holder created their commitment before quantum hardware existed. This approach also addresses a gap in a previous proposal by including a rescue path for wallets derived through a deterministic key generation standard. However, the proposal requires Bitcoin to adopt a verification protocol, which would need a separate soft fork with broad community consensus. Ultimately, the success of this proposal depends on the willingness of holders, including Satoshi, to create a commitment, and it does not provide a solution for coins that remain exposed if their owners are no longer present.