New Quantum Proposal Offers Solution for Bitcoin's Satoshi Problem

Quantum computing has long posed a threat to Bitcoin, particularly for holders of old wallets with exposed public keys. This includes the estimated 1.1 million bitcoins linked to Satoshi Nakamoto, worth around $84 billion. A potential solution involves a soft fork that phases out legacy address types, but this would require dormant holders like Satoshi to publicly move their assets or risk losing them. In response, Dan Robinson of Paradigm has proposed a system called Provable Address-Control Timestamps, or PACTs, which enables holders to generate a private proof of ownership without spending their coins. This involves 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 submit a zero-knowledge proof to redeem their assets without revealing any information about the original address or timestamp. While PACTs offer a potential rescue path for wallets derived through BIP-32, they require Bitcoin to adopt a STARK verification protocol, which would need a separate soft fork and substantial new infrastructure. Ultimately, PACTs provide a way to mitigate the risks associated with quantum computing, but their effectiveness depends on the cooperation of holders like Satoshi.