A new Bitcoin Improvement Proposal (BIP-361), dubbed "Post Quantum Migration and Legacy Signature Sunset," has ignited significant discussion within the cryptocurrency community by proposing a phased plan to freeze Bitcoin held in quantum-vulnerable addresses. The proposal, co-authored by cypherpunk Jameson Lopp and five other researchers, aims to proactively address the long-term threat posed by quantum computers to the network's security. It suggests that users migrate their holdings to quantum-resistant addresses or risk their coins becoming unspendable after a set period.
The initiative, drafted on GitHub, outlines a three-phase soft fork. Approximately three years after activation, Phase A would prevent new Bitcoin from being sent to old-style, vulnerable addresses. Five years post-activation, Phase B would invalidate legacy signatures, effectively freezing any Bitcoin remaining in unmigrated addresses. A potential Phase C would offer a recovery mechanism using zero-knowledge proofs for owners who missed the deadline but retain their seed phrases.
The proposal stems from concerns that an estimated 1.7 million BTC, including a significant portion of Satoshi Nakamoto's original holdings, are in early pay-to-public-key (P2PK) addresses, which are not quantum-proof. If quantum computing advances sufficiently, these coins could be vulnerable to theft, potentially undermining the network's value and trust. Proponents argue this is a defensive measure to safeguard Bitcoin's future.
However, BIP-361 has faced substantial backlash from parts of the Bitcoin community. Critics, including Bitcoin protocol developer Mark Erhardt and Bitcoin Magazine editor Brian Trollz, have labeled the proposal "authoritarian" and "confiscatory," arguing it fundamentally challenges Bitcoin's core principles of immutability and property rights. Marty Bent, founder of TFTC, called the idea "laughable," while Phil Geiger of Metaplanet quipped, "We have to steal people’s money to prevent their money from being stolen."
Amidst this controversy, Kain Warwick (@kaiynne), founder of prominent DeFi protocols Synthetix and Infinex, expressed strong approval for the proposal. Warwick, an influential figure in decentralized finance, stated simply: > "This is genius." His endorsement, shared by crypto journalist Laura Shin, highlights the divide in opinion regarding the necessity and implications of such a drastic measure. The debate continues as developers weigh the philosophical tenets of Bitcoin against the looming threat of quantum advancements.
