New Proposal Offers Bitcoin Holders a Way to Prove Control Without Revealing Identity

Concerns surrounding Bitcoin's vulnerability to quantum computing have long been intertwined with the issue of Satoshi Nakamoto's untouched funds. Approximately 1.1 million bitcoin, valued at around $84 billion and attributed to the cryptocurrency's pseudonymous creator, remain in old wallets with exposed public keys, making them susceptible to theft by powerful quantum computers. The straightforward solution involves implementing a soft fork that phases out the use of legacy address types, thereby forcing holders to migrate to quantum-safe formats before potential attackers can exploit their private keys. However, this approach poses a significant challenge for long-dormant holders like Satoshi, as they would be required to publicly reveal their presence or risk losing access to their assets. In response, Dan Robinson of Paradigm has proposed a solution called Provable Address-Control Timestamps, or PACTs, which enables holders to generate a proof of ownership without moving their coins. This is achieved by creating a unique cryptographic commitment using a random salt and the BIP-322 standard for signing messages from a Bitcoin address. The commitment is then timestamped through OpenTimestamps, a service that anchors data onto the Bitcoin blockchain, and remains private until the owner decides to spend their coins. If a soft fork that freezes quantum-vulnerable coins is implemented, the protocol could include a rescue path that accepts a zero-knowledge proof, demonstrating that the holder created their commitment before the existence of quantum hardware. While this solution addresses the issue of protecting dormant assets, it requires the eventual adoption of a STARK verification protocol, which would necessitate a separate soft fork and broad community consensus. The proposed PACTs offer a potential middle ground in the debate surrounding the freeze proposal, allowing holders to secure their assets without being forced to choose between protecting against quantum theft and respecting dormant property rights.