Quantum Came for Your Keys, Wyoming Said "Hold My Seed Phrase" 🌱

Researchers at AmericanFortress, a Wyoming-based blockchain security and cryptography firm focused on post-quantum security and digital asset infrastructure, have proposed a cryptographic system they say could let Bitcoin and other blockchain wallets survive future quantum attacks without changing existing wallet addresses. The paper, titled "ZKPoSP: Post-Quantum Zero-Knowledge Proofs for Hierarchical Deterministic Wallets," outlines replacing traditional elliptic curve signatures with zero-knowledge proofs while preserving compatibility with hierarchical deterministic wallets.

The researchers framed the effort around "Q-Day," the point at which a fault-tolerant quantum computer could run Shor's algorithm to derive private keys from public keys, breaking the elliptic curve cryptography that secures Bitcoin and many other chains. "Recent advances in quantum hardware, including Google's Willow processor, have substantially narrowed the timeline to cryptographically relevant quantum computers," the authors wrote. "In the blockchain setting, where addresses and key derivation standards such as BIP32, BIP44, and SLIP-10 are the dominant infrastructure for wallet management, a quantum computer running Shor's algorithm can recover any elliptic-curve private key from the corresponding public key, threatening every wallet in production today."

Rather than requiring users to migrate funds to new quantum-safe addresses, the proposed system swaps digital signatures for zero-knowledge proofs that verify ownership of a wallet's seed phrase. Because the seed itself remains secret, the authors argue legitimate owners could still prove control of their wallets even if individual private keys are compromised. The paper introduces ZKPoSP (Zero-Knowledge Proof of Seed Provenance) and QBIP32, a key derivation scheme built to support multiple elliptic curves while staying compatible with existing hierarchical deterministic wallets.

AmericanFortress researchers implemented the system in Rust using the RISC Zero zero-knowledge virtual machine. Prototype benchmarks showed proof generation times of roughly 12 to 13 seconds and verification times of about 9 to 10 milliseconds, with the paper also describing a post-Q-Day mode that reduces proving time for some operations. The research has not been adopted by any blockchain network, and any deployment would require adoption by developers, wallet providers, exchanges, miners, and users.

The paper lands amid growing industry focus on post-quantum cryptography, and Bitcoin presents a particular challenge because spending coins exposes their public keys on the blockchain, leaving a sufficiently powerful quantum computer able to derive private keys and forge valid transaction signatures. It is the latest in a series of post-quantum efforts across the crypto sector, including earlier work from Project Eleven.