Project Eleven unveils post-quantum Bitcoin wallet recovery tool
Project Eleven has developed a cryptographic fallback to verify Bitcoin wallet ownership after quantum attacks, addressing the risk that millions of stranded coins could become permanently unspendable.
Security firm Project Eleven on Thursday unveiled a cryptographic technique designed to let Bitcoin users prove wallet ownership after quantum computers break the network's standard encryption. The prototype offers a potential safety net for a scenario where traditional digital signatures no longer guarantee control of digital assets.
The threat centers on "Q-Day," the theoretical point when quantum computers can break the elliptic curve cryptography securing Bitcoin transactions. Once this happens, an attacker could derive a private key from a public key and forge the necessary signatures to move funds. “After Q-Day, once a quantum computer can derive an ECC private key from its public key, a valid signature no longer proves ownership. Both the quantum adversary and the legitimate owner are able to produce identical signatures,” Project Eleven CEO Alex Pruden wrote.
To solve this, Project Eleven's technique relies on a wallet's key derivation path rather than its digital signature to verify ownership. It allows a user to cryptographically prove they control the parent seed phrase used to generate the compromised private key. “So even after Q-Day, an attacker who's broken your address's private key does not hold, and can't compute, the seed phrase it was derived from. Proving you know that parent key, without revealing it, is something only the real owner can do,” Pruden wrote.
The implementation was built by Jim Posen, lead maintainer of the open-source Binius zero-knowledge proof system, and adapts a method called "signature lifting" proposed by researchers Alon Sattath and Robert Wyborski. However, the code remains unaudited and would require broader Bitcoin protocol support before it could be deployed.
The proposal functions as a last resort for investors who fail to migrate their holdings to quantum-safe addresses in time. In June, Coinbase's quantum advisory council warned that roughly 7 million Bitcoin could eventually be vulnerable if owners do not move their funds during a network-wide upgrade. Pre-emptive efforts are already advancing, with developers moving the quantum-resistant BIP-360 into formal review in February and BTQ Technologies launching a working implementation on a testnet in March.
Policy momentum builds
The financial and regulatory focus on post-quantum cryptography has intensified this year, with President Donald Trump signing executive orders in June to accelerate the federal government's transition to quantum-resistant encryption. For Bitcoin holders, the combination of protocol upgrades and fallback recovery tools represents the emerging infrastructure for navigating a post-quantum economy. “As much as I'd love for the entire world to take a quantum migration plan seriously, the reality is that some digital asset wallets will miss the window. This gives them a fallback: prove ownership through derivation, not signature, even after that window closes,” Pruden wrote.
