New Proposal Offers Bitcoin Holders a Way to Prove Control Without Exposing Themselves to Quantum Computing Risks

The specter of quantum computing has long posed a challenge for Bitcoin, with a significant portion of the cryptocurrency, including the estimated 1.1 million bitcoin linked to its creator Satoshi Nakamoto, at risk of being compromised due to exposed public keys. A proposed soft fork, BIP-361, aims to phase out legacy addresses over a five-year period, but this solution presents a dilemma for long-dormant holders like Satoshi, who would need to publicly move their assets to avoid losing access. In response, Dan Robinson of Paradigm has introduced a concept called Provable Address-Control Timestamps, or PACTs, which enables holders to generate a private proof of ownership at a specific point in time without revealing any information publicly until they choose to spend their coins. This approach involves creating a cryptographic commitment using a random salt and BIP-322, then anchoring it to the Bitcoin blockchain via OpenTimestamps. If a soft fork is implemented to freeze vulnerable coins, holders can submit a zero-knowledge proof to reclaim their assets without disclosing sensitive information. While PACTs offer a potential solution for wallets derived through BIP-32, they require the adoption of a STARK verification protocol, which would necessitate a separate soft fork and substantial infrastructure development. Ultimately, the success of PACTs hinges on the willingness of holders, including Satoshi, to create these private proofs, as they cannot be generated retroactively.