Bitcoin developers have proposed BIP-361, aiming to freeze tokens in addresses vulnerable to quantum attacks.

Techub News, according to Cointelegraph, six Bitcoin quantum security researchers including Jameson Lopp have proposed BIP-361, suggesting to freeze tokens in addresses vulnerable to quantum attacks on the Bitcoin network, including the approximately $74 billion worth of Bitcoin held by Satoshi Nakamoto, to prevent these cryptocurrencies from being stolen after the popularization of quantum computers. This proposal has sparked controversy within the community, with critics calling it "authoritarian and confiscatory," arguing that there is no reasonable justification for forcing upgrades and invalidating old spends.

BIP-361 is based on BIP-360 released in February, which proposed a soft fork for a new output type called "Pay to Merkle Root" (P2MR). It works similarly to Bitcoin's existing Taproot (P2TR) addresses but removes the key path vulnerable to quantum attacks. While BIP-360 can protect newly issued tokens in the future, it cannot address the issue of approximately 34% of the token supply still being vulnerable unless these tokens are moved to new addresses. BIP-361 proposes that, three years after activation, Phase A of the proposal will prevent any new BTC from being sent to legacy addresses, and all users will use quantum-resistant address types. The second phase (B) will invalidate legacy signatures, effectively freezing any Bitcoin still residing in vulnerable addresses within five years of activation.