Concerns about quantum computing have long been intertwined with the enigma of Satoshi Nakamoto. Millions of bitcoins, including those attributed to the pseudonymous creator, worth approximately $84 billion, are at risk due to exposed public keys in outdated wallets.
A proposed solution involves a soft fork that would eventually disallow transactions from these legacy addresses, forcing holders to migrate to quantum-secure formats. However, this approach poses a dilemma for dormant holders like Satoshi, who would have to publicly reclaim their assets or risk losing them. Dan Robinson of Paradigm has introduced an alternative, dubbed Provable Address-Control Timestamps (PACTs), which enables holders to timestamp proof of ownership without revealing their identity or transferring coins.
This method involves generating a unique cryptographic commitment using a random salt and BIP-322, then anchoring it to the Bitcoin blockchain via OpenTimestamps. If Bitcoin implements a soft fork that freezes vulnerable coins, holders can later submit a zero-knowledge proof to redeem 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 participation of holders like Satoshi, who must proactively create a commitment to protect their assets.