Many are assumed to belong to pseudonymous Bitcoin creator Satoshi Nakamoto and other owners who lost their keys, meaning they can never be moved to safety. Another 5 million or so are exposed through address reuse, according to Project11, a research group tracking the issue, although most of them are believed to be active holdings in exchange wallets.
Exchanging quantum-resistant signatures is the easy part, but the fight is over the coins no one moves. One side advocates for a strict deadline, after which the signature schemes Bitcoin uses today, ECDSA and Schnorr, will no longer be accepted and any unmigrated coins will become unusable. Leaving them alive, this side says, hands a future attacker, potentially a sanctioned state like North Korea, a stash of bitcoins large enough to drive down the price and tarnish the legitimacy of the network.
The other side calls that confiscation a violation of the absolute property rights upon which Bitcoin was built, and warns that it sets a precedent for freezing currencies under government pressure later.
Among them are the various proposals that CoinDesk has followed over the past two months.
Hourglass would limit the number of vulnerable coins that can be spent per block to prevent a supply flood. BIP-361, from developer Jameson Lopp and others, would allow migrated holders to prove ownership after the outage with a quantum-resistant proof that doesn’t expose any keys. PACTs, from Paradigm’s Dan Robinson, would allow owners to mark the date of a private claim now and move funds later without disclosing anything today.
