New Quantum Proposal Offers Solution for Bitcoin Holders to Prove Ownership Without Exposing Assets

Concerns surrounding Bitcoin's vulnerability to quantum computing have long been intertwined with the enigma of Satoshi Nakamoto. Millions of bitcoins, including the approximately 1.1 million attributed to the pseudonymous creator, worth around $84 billion, are stored in outdated wallets with exposed public keys, rendering them susceptible to theft by powerful quantum computers. The apparent solution is a soft fork that would gradually phase out the use of vulnerable address types, compelling holders to migrate to quantum-resistant formats before attackers can exploit their private keys. However, this approach poses a dilemma for dormant holders like Satoshi, who would need to publicly reveal their presence or risk losing access to their assets. In response, Dan Robinson of Paradigm has introduced a concept called Provable Address-Control Timestamps (PACTs), which allows holders to generate a proof of ownership at a specific date without publicly disclosing their identity. By utilizing a random salt and BIP-322, a standard for signing messages from a Bitcoin address without spending, holders can create a proof of ownership, bundle it with the salt, and timestamp it via OpenTimestamps. This commitment remains private, and if Bitcoin implements a soft fork that freezes vulnerable coins, the protocol could include a rescue path that accepts a zero-knowledge proof, demonstrating the holder created their commitment before the existence of quantum hardware. This approach not only offers a potential solution for Satoshi but also addresses a specific gap in the existing proposal by providing a rescue path for wallets derived through BIP-32. Nevertheless, the implementation of PACTs requires the adoption of a STARK verification protocol, which would necessitate a separate soft fork and broad community consensus. Ultimately, the success of PACTs hinges on the willingness of holders, including Satoshi, to create a commitment, as no PACT can be retroactively generated if the holder is genuinely absent.