Blockchain security firm AmericanFortress has proposed a cryptographic method designed to protect existing Bitcoin, Ethereum and Solana wallets against future quantum-computer attacks without requiring users to transfer funds, rotate keys or change addresses. The scheme seeks to add post-quantum security while leaving current wallet addresses intact.

The approach relies on zero-knowledge proofs generated from a wallet’s original seed phrase rather than replacing the underlying elliptic-curve cryptography. Participating network nodes would verify the proofs, allowing users to continue signing transactions with their existing keys. The method is described as compatible with seed-based hierarchical deterministic wallets employed across Bitcoin, Ethereum, Solana and other networks that depend on elliptic-curve cryptography. Details appear in a technical paper posted to the Cryptography ePrint Archive that has not yet undergone peer review.

An estimated $470 billion in Bitcoin holdings could become vulnerable if sufficiently powerful quantum computers emerge. Other firms are pursuing alternative post-quantum solutions. One hardware wallet for Ethereum and compatible networks generates post-quantum signatures on dedicated devices using SPHINCS+C10 algorithms and smart-account standards. Industry participants have also advanced broader research, including a $15 million commitment to Bitcoin quantum-security studies, proposals for migrating Ethereum accounts to quantum-resistant cryptography and plans by one network to introduce quantum-resistant accounts by 2027.