Bitcoin Developers Propose BIP-361 to Freeze Quantum-Vulnerable Legacy Addresses

The proposal reflects growing urgency around the future-proofing of Bitcoin against potential quantum risks.

Jameson Lopp and five other individuals have proposed freezing all quantum-vulnerable Bitcoin addresses to protect BTC from future quantum threats.

The motivation behind this development comes from a long-standing concern in the community that advances in the technology could eventually compromise the network’s current security structure.

Migration Towards Safer Wallets

In a Tuesday post on GitHub, the group outlined a three-step process to stop using older and less secure wallet types under Proposal BIP-361.

The draft builds on work that was first introduced in February on BIP-360. In this version, they proposed a soft fork that would introduce a new output type called Pay-to-Merkle-Root (P2MR). This, in turn, would remove the original key path found in Bitcoin addresses that makes the public keys vulnerable to exposure.

Under the latest proposal, the first phase would prevent users from sending Bitcoin to older addresses deemed quantum-vulnerable. This is meant to encourage people toward upgrading their wallets to newer models.

The second part would come two years later and introduce a stricter cut-off. At this stage, any wallet still using the old signature style will no longer be able to send Bitcoin at all. Simply put, if exchanges and everyday users do not move their holdings to newer and safer wallets by this point, they will become stuck and unusable.

However, developers are also discussing a possible third phase that would give people an opportunity to recover their funds if they missed the deadline. Furthermore, this step is not yet confirmed and requires more research and consensus within the Bitcoin community.

You may also like:

What this Means For the Network

Industry projections show that quantum machines could become a real danger to Bitcoin’s cryptography as early as 2027 to 2030. At the same time, estimates also indicate that roughly 34% of the flagship cryptocurrency’s supply is already exposed to the vulnerability.

The proposal says that such an attack may not be obvious right away, which makes it easier for bad actors to gain access to the vulnerable addresses without being detected. As such, developers argue that waiting until the threat is immediate would be too risky.

The post also mentions some of the benefits that could come from a network-wide upgrade. For instance, such an update would make the whole network more resilient against future attacks and reduce uncertainty over its long-term security.

Another positive aspect the draft highlights is how a clear timeline would align everyone in the ecosystem. This, according to the developers, is because it would make it easier for wallets, exchanges, and institutions to prepare in advance for any future attacks instead of reacting while in a crisis.

Some institutions are already taking steps towards securing their holdings, with Blockstream Research recently announcing that it has deployed the first transactions on a live Bitcoin sidechain protected by post-quantum cryptography.

Meanwhile, the total supply of Bitcoin in circulation would greatly reduce once a huge portion of it becomes permanently inaccessible. While this may increase scarcity, developers also believe that it would make people more responsible for their holdings.