Bitcoin‘s longstanding discussion about quantum threats moved closer to reality as BIP-361, a draft proposal aimed at safeguarding the network from future quantum computing risks, surfaced on the official Bitcoin BIPs repository. The plan centers on a gradual migration away from legacy ECDSA and Schnorr signatures toward quantum-resistant cryptography once post-quantum solutions are ready.
BIP-361 details Bitcoin’s quantum migration pathway
BIP-361, titled “Post Quantum Migration and Legacy Signature Sunset,” was co-authored by Jameson Lopp and five other contributors. The proposal outlines a phased soft fork that would unfold over several years, designed to minimize risk as post-quantum technology advances. Activation would require the development and adoption of a future Bitcoin Improvement Proposal for quantum-safe signatures—a technology not yet finalized.
Under the proposal, the process would begin with Phase A, set to activate roughly 160,000 blocks, or about three years after network approval. During this phase, users would be barred from sending new BTC to addresses reliant on the older, quantum-vulnerable signature schemes, although spending from existing legacy outputs would still be possible at this stage.
Two years after Phase A, Phase B would tighten rules on spending from legacy addresses. The network would then enforce stricter verification for ECDSA and Schnorr spends, using a rescue mechanism intended to prevent quantum-enabled theft. This gradual rollout aims to reduce Bitcoin’s attack surface without forcing sudden, disruptive changes on the community.
By staggering restrictions across phases, the proposal seeks to give wallets, custodians, exchanges, and miners the time they need to adapt well before quantum risk becomes an urgent threat to network security or coinholder confidence.
Mini dictionary: ECDSA (Elliptic Curve Digital Signature Algorithm) and Schnorr are digital signature schemes used in Bitcoin to verify the authenticity of transactions. Quantum computers may eventually break these schemes, making them a potential security risk for cryptocurrencies.
Quantum risk and exposed public keys’ impact on Bitcoin
According to the draft, as of March 1, 2026, more than 34% of all bitcoin had been linked to on-chain addresses that revealed their public keys. The proposal argues that these coins would be particularly vulnerable if a sufficiently advanced quantum computer emerged, enabling an attacker to derive private keys and steal funds.
The coauthors also point out that attackers could operate covertly, possibly moving compromised coins at a later date—making it harder for the broader market and ecosystem participants to detect real-time threats. That’s why BIP-361 emphasizes the need for a clear migration timeline: so ecosystem participants, including wallets, exchanges, and miners, are not caught off guard and have the time to secure their holdings.
| Metric | Current (March 1, 2026) | Risk if quantum computer emerges |
|---|---|---|
| BTC with revealed public keys | 34% of total supply | Vulnerable to theft |
| BTC with hidden public keys | 66% of total supply | Lower immediate risk |
This context has spurred widespread discussion on X (formerly Twitter), with accounts like Wise Advice underscoring the urgency of preparing for quantum-capable adversaries before actual incidents occur.
Next steps for Bitcoin investors
For now, BIP-361 remains a draft proposal and is not scheduled for activation. Its implementation is contingent on the future adoption of a quantum-safe cryptographic standard within the network. Thus, the ongoing debate primarily involves Bitcoin core developers and other technical contributors.
Market participants are closely watching the proposal for signs of progress, as network upgrades of this scale could affect trust, adoption timelines, and the security protocols used by wallets and custodians. If adopted, the most critical challenge would likely be ensuring timely and secure migration of older coins to new, quantum-resistant addresses.
The proposal has already prompted many in the Bitcoin community—including developers, investors, and service providers—to start assessing their exposure and preparedness for quantum computing risks, well ahead of any expected breakthrough.
