Q-Day and Bitcoin: what should happen to old coins with exposed keys?

[CipherMonk]

This forum is named after Q-Day, so this one feels close to home. If a large enough quantum computer arrives, it could in theory work out private keys from public keys using Shor's algorithm. That would put certain Bitcoin addresses at risk, especially older ones where the public key is already visible on the blockchain. Some estimates suggest around a million or more coins sit in these vulnerable addresses, including coins widely believed to belong to Satoshi Nakamoto

The Bitcoin community is debating what to do. Developers have proposed new quantum resistant address types, such as the BIP 360 proposal, so people can move their coins to safer addresses. A more controversial idea is that, after a deadline, coins in vulnerable addresses that have not moved could be frozen or made unspendable. Supporters say this protects the network from a sudden flood of stolen coins, while critics say it breaks the principle that nobody can touch your money

It is a fascinating mix of technology, ethics and philosophy. Is it fair to freeze coins whose owners may have died or lost their keys? Is it worse to let a quantum attacker take them? Should the network act early, or wait until the threat is proven? There are no easy answers. Reasonable people disagree strongly on this one

I am keeping this away from prices and trading, and focusing on the technical and ethical questions. Nobody knows exactly when, or if, quantum computers will be powerful enough. But Bitcoin upgrades take years to agree, so the debate is happening now

What do you think should happen to old coins with exposed keys? Freeze them, leave them or something in between?

[IronFist21]

People with lost keys have already lost those coins. Freezing them changes nothing for them. It just stops a thief benefiting. Freezing protects everyone else from a sudden shock to the system. That seems fair to me

[UnratedRyan68]

Quantum resistant addresses should be added as soon as possible. Even if Q-Day is decades away, the upgrade takes years to roll out. Better early than sorry. Signature sizes are bigger, which raises fees, so there are trade offs to work through

[Anthony87]

The debate shows how hard governance is in a decentralised system. No CEO can just decide. Every change needs broad agreement. Bitcoin governance moves slowly by design. Some see that as a weakness, others as its greatest strength