New Bitcoin Proposal Offers a Solution for Proving Control Without Moving Funds

Concerns over quantum computing have long plagued Bitcoin, with millions of coins in old wallets with exposed public keys at risk of theft if powerful quantum computers emerge. This includes the approximately 1.1 million bitcoin attributed to Satoshi Nakamoto, currently valued at around $84 billion. A proposed solution involves a soft fork that would phase out vulnerable address types, forcing holders to move to quantum-safe formats. However, this would require long-dormant holders like Satoshi to publicly reveal their presence, risking their assets if they fail to do so. 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 or revealing any information publicly. This is achieved by creating a cryptographic commitment using a random salt and BIP-322, then timestamping it through OpenTimestamps. If Bitcoin activates a soft fork that freezes vulnerable coins, holders can use a STARK proof to demonstrate that they created their commitment before quantum hardware existed, allowing them to spend their coins without revealing any sensitive information. PACTs also provide a rescue path for wallets derived through BIP-32, addressing a specific gap in the existing proposal. However, this solution requires the adoption of a STARK verification protocol, which would need a separate soft fork with broad community consensus. The verification infrastructure does not currently exist in Bitcoin and would require significant new development, including multisig wallets, complex scripts, and hardware wallet support. Ultimately, PACTs offer a way to make the debate around quantum resistance less binary, providing a potential solution that balances protection against quantum theft with respect for dormant property rights.