New Proposal Offers Bitcoin Holders a Way to Prove Control Without Moving Funds

Bitcoin has long been concerned about the potential impact of quantum computing, particularly for the millions of bitcoin held in old wallets with exposed public keys, including those attributed to Satoshi Nakamoto. A proposed soft fork to phase out quantum-vulnerable addresses could force holders to move their funds, but this would require dormant holders like Satoshi to publicly reveal themselves. 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 without spending any funds. This proof can be timestamped and kept private until the holder needs to spend their coins. The proposal relies on a random salt and BIP-322 to produce a proof of ownership, which is then bundled and timestamped through OpenTimestamps. If a soft fork 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. While PACTs offer a potential solution, they require Bitcoin to adopt a STARK verification protocol and substantial new infrastructure. The proposal does not guarantee protection for Satoshi's coins if he is no longer able to make a commitment, but it does provide a way to make the debate around quantum protection less binary, offering a potential middle ground between protecting against quantum theft and respecting dormant property rights.