New Bitcoin Quantum Proposal Provides a Solution for Proving Control Without Moving Funds

Concerns over quantum computing have long plagued Bitcoin, with a significant problem being the vulnerability of millions of bitcoin in old wallets with exposed public keys to potential theft by powerful quantum computers. This includes the approximately 1.1 million bitcoin linked to Satoshi Nakamoto, valued at around $84 billion. A proposed solution involves a soft fork that would phase out the use of legacy address types, forcing holders to move to quantum-safe formats. However, this approach poses a challenge for long-dormant holders like Satoshi, who would need to publicly reclaim their assets. In response, Dan Robinson of Paradigm has introduced the concept of Provable Address-Control Timestamps (PACTs), which enable holders to generate a proof of ownership and timestamp it without revealing any information publicly until they need to spend their coins. This approach involves creating a cryptographic commitment using a random salt and BIP-322, then bundling it with a timestamp through OpenTimestamps. If Bitcoin implements a soft fork that freezes quantum-vulnerable coins, the protocol could include a rescue path that accepts a zero-knowledge proof, allowing holders to spend their coins without revealing any sensitive information. While PACTs offer a potential solution, they require the adoption of a STARK verification protocol, which would need a separate soft fork and broad community consensus. The success of PACTs hinges on the ability of holders, including Satoshi, to create a commitment before quantum hardware becomes a threat. If Satoshi is no longer active, the coins remain vulnerable to quantum theft or community freeze.