New Proposal Offers Satoshi Nakamoto a Way to Prove Control Over Bitcoin Without Transferring Funds

The concerns surrounding Bitcoin and quantum computing have long been intertwined with the issue of Satoshi Nakamoto's involvement. Millions of bitcoins, including the roughly 1.1 million attributed to Satoshi Nakamoto, worth around $84 billion, are currently at risk due to their exposure in old wallets with public keys that could be vulnerable to theft once powerful quantum computers are developed. One possible solution is to implement a soft fork, which would upgrade the existing network rules to eventually stop allowing transactions from legacy address types, forcing holders to move their assets to quantum-safe formats before attackers can derive their private keys. A group of developers, including Jameson Lopp, proposed this solution in mid-April through BIP-361, which would phase out quantum-vulnerable addresses over a five-year period and freeze any coins that fail to migrate. However, this proposal creates a new issue: long-dormant holders like Satoshi would need to publicly reveal their presence or risk losing access to their assets. To address this concern, Dan Robinson, a general partner at Paradigm, has proposed a new concept called Provable Address-Control Timestamps, or PACTs. The core idea behind PACTs is to generate a proof of ownership without moving any coins and to reveal nothing publicly until the owner of the wallet actually needs to spend their assets. This is achieved by generating a random salt and using BIP-322 to produce a proof of ownership, which is then bundled together with the salt and timestamped through OpenTimestamps, a free service that anchors data onto the Bitcoin blockchain. The salt, proof, and timestamp files remain private, and if Bitcoin later activates a soft fork that freezes quantum-vulnerable coins, the protocol could include a rescue path that accepts a STARK proof, showing the holder created their commitment before quantum hardware existed. When the holder wants to spend their coins, they submit the proof, and the network releases the coins without revealing any information about the address, amount, or original timestamp. PACTs also address a specific gap in BIP-361 by providing a rescue path for wallets derived through BIP-32, the deterministic key generation standard introduced in 2012. However, for PACTs to work, Bitcoin would need to adopt a STARK verification protocol, which would require a separate soft fork with broad community consensus. The verification infrastructure does not currently exist in Bitcoin and would need substantial new development, including multisig wallets, complex scripts, and hardware wallet support. The only constraint that PACTs cannot work around is that the protocol only protects Satoshi if he, or whoever currently controls those keys, makes the commitment. If Satoshi is genuinely gone, no PACT can be retroactively created, and the coins remain exposed to either quantum theft or community freeze. What PACTs do offer is a way to make the BIP-361 debate less binary, providing an alternative to the current freeze proposal that forces a choice between protecting against quantum theft and respecting dormant property rights. The question remains whether Satoshi will utilize this new proposal.