TechFlow News, May 2 — According to a CoinDesk report, Dan Robinson, General Partner at Paradigm, published a proposal titled “Provable Address-Control Timestamps” (PACTs) on Friday. PACTs aim to protect legacy Bitcoin wallets from future quantum-computing attacks without requiring users to immediately move their coins.
PACTs allow holders to privately generate and timestamp a cryptographic proof of ownership today. In the future, if quantum-vulnerable addresses are frozen on the network, assets can be unlocked via quantum-resistant STARK zero-knowledge proofs. The specific process is as follows: the holder generates a random salt, uses the BIP-322 standard (which enables signing arbitrary messages from a Bitcoin address without spending) to produce a proof of ownership, packages the salt and proof into an on-chain commitment, anchors it to the Bitcoin blockchain via the OpenTimestamps service, and keeps the associated files private.
This proposal complements BIP-361, introduced in mid-April by prominent developers including Jameson Lopp. BIP-361 plans to phase out quantum-vulnerable addresses over five years, compelling holders to proactively migrate their funds—or risk having them frozen. This poses a challenge for long-dormant assets, including Satoshi Nakamoto’s estimated 1.1 million BTC (~$84 billion).
PACTs also fill a gap in BIP-361’s remediation pathway for wallets derived using BIP-32 (the deterministic key-generation standard introduced in 2012). However, wallets generated before 2012—including most of Satoshi Nakamoto’s known addresses—do not use BIP-32 and thus cannot be remediated via that pathway. Adoption of this proposal requires a Bitcoin soft fork to integrate STARK verification, and protection applies only if Satoshi Nakamoto himself—or whoever currently controls the private keys—actively makes the required commitment.
