New BIP-361 Proposal Seeks to Freeze Bitcoin Addresses Exposed to Quantum Threats

Highlights:

• Bitcoin developers proposed BIP-361 to move users away from quantum-vulnerable wallet address formats.
• The plan gives users years to shift funds before older Bitcoin formats stop working.
• Developers say early action matters as quantum research advances and exposed Bitcoin keys remain at risk.

Bitcoin developers have introduced a new plan to prepare the network for a future quantum threat. The proposal, called BIP-361, outlines a clear path to phase out older Bitcoin address types that could be broken by powerful quantum machines. If adopted, the proposal would give users years to move their funds to newer, quantum-resistant addresses before older formats stop working.

BIP-361 is titled “Post Quantum Migration and Legacy Signature Sunset“, which was posted as a draft to GitHub on Tuesday. The proposal comes from a team of Bitcoin contributors, including Cypherpunk Jameson Lopp. It is currently in draft status and would require broad community support before becoming part of Bitcoin’s rules. 

The proposal comes as quantum computing research keeps moving forward. Right now, no quantum computer can break Bitcoin’s encryption. Still, experts say a powerful machine could one day recover private keys from public keys already visible on the blockchain. Because of that, BIP-361 tries to prepare early by setting a clear timeline for moving to quantum-resistant address formats.

BIP-361 Proposes Freezing Quantum-Vulnerable Bitcoin Addresses

Bitcoin developers and researchers have proposed BIP-361, which suggests freezing early Bitcoin addresses considered to have quantum vulnerabilities—primarily P2PK addresses with publicly exposed public keys—to… pic.twitter.com/C5zksSnW7l

— Wu Blockchain (@WuBlockchain) April 15, 2026

How the Three-Phase Plan Would Work

BIP-361 divides the transition into three clear phases, and each phase has its own goal and timeline.

Phase A would start around three years after the proposal is activated. In this stage, users could still spend Bitcoin from older address types, but they would no longer be able to send new funds to them. This step is meant to push users toward newer, post-quantum address formats for receiving Bitcoin.

Phase B would begin about two years later. At a set block height, the network would stop accepting transactions that use the older ECDSA or Schnorr signature methods. After that point, any Bitcoin still held in vulnerable addresses would basically become frozen. Because of this, the proposal creates a strong reason for users and services to upgrade well before the deadline.

Phase C remains under research. If a user misses the Phase B deadline, a future update might allow recovery of frozen funds. This could involve a zero-knowledge proof, a cryptographic method that lets someone prove they own a wallet seed phrase without revealing the phrase itself. This safety net would help honest users who lost access due to inactivity or poor planning.

Waiting Too Long Could Increase Bitcoin’s Quantum Risk

The draft strongly argues that Bitcoin should not wait for a real attack before taking action. It says that, as of 1 March, more than 34% of all bitcoin had already exposed a public key on-chain.

That means those UTXOs could become targets if quantum computers grow strong enough. The authors believe a clear public deadline would push the industry to upgrade sooner instead of putting it off.

BIP-361 also says waiting too long could make the problem bigger. Big Bitcoin changes usually take years because wallet providers, exchanges, miners, custodians, and hardware companies all need time to adjust. The authors believe a clear public deadline would push the whole industry to upgrade earlier instead of delaying the issue.

For now, BIP-361 is still only a draft and not an actual rule change. Even so, it gives a clear picture of one path Bitcoin could follow if the community decides quantum resistance is no longer something to discuss only for the future.

Recently, Google researchers also warned that future quantum computers could break the encryption used in Bitcoin and other systems earlier than expected. The tech giant also mentioned that this could happen around 2029 if progress continues at the current pace.

🚨JUST IN: GOOGLE SETS 2029 DEADLINE AS QUANTUM THREAT LOOMS OVER BITCOIN

Google has set a 2029 deadline for post-quantum cryptography migration, warning quantum risks are approaching faster than expected.

The company says current encryption standards could eventually be… pic.twitter.com/LbGSmms3RQ

— BSCN (@BSCNews) March 26, 2026