New Proposal Offers Potential Solution for Bitcoin's Quantum Computing Conundrum

The specter of quantum computing has long posed a significant threat to bitcoin, with a substantial amount of the cryptocurrency stored in outdated wallets with exposed public keys, leaving them susceptible to theft. This vulnerability extends to the approximately 1.1 million bitcoin attributed to the cryptocurrency's enigmatic creator, Satoshi Nakamoto, valued at around $84 billion. A proposed solution involves implementing a soft fork that would gradually phase out the use of legacy address types, compelling holders to transition to quantum-resistant formats before potential attackers can exploit them. However, this approach presents a dilemma for dormant holders, including Satoshi, who would be forced 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 without actually 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 resulting proof is then timestamped and bundled into an on-chain commitment, with the associated files remaining private. If a soft fork is implemented that freezes vulnerable coins, the protocol could incorporate a rescue mechanism that accepts a zero-knowledge proof, demonstrating that the holder created their commitment prior to the existence of quantum hardware. This proof can be submitted when the holder wishes to spend their coins, and the network will release the funds without revealing any sensitive information. PACTs address a specific shortcoming in the existing proposal by providing a rescue path for wallets derived through the BIP-32 standard. Nevertheless, the implementation of PACTs necessitates the adoption of a STARK verification protocol, which would require a separate soft fork and broad community consensus. The development of the necessary verification infrastructure, including multisig wallets and complex scripts, would also be required. Ultimately, the success of PACTs hinges on the participation of holders, including Satoshi, who must create the commitment themselves. If Satoshi is indeed no longer involved, no PACT can be retroactively created, leaving the coins vulnerable to either quantum theft or community freeze. The introduction of PACTs offers a potential middle ground in the debate surrounding the proposed freeze, allowing for a more nuanced approach that balances the need to protect against quantum theft with the importance of respecting dormant property rights.