Ledger, Bitcoin, and Ethereum Navigate Post-Quantum Cryptography Standards

Quantum computing poses an abstract threat to cryptocurrency wallets, but experts aren't waiting for it to become a reality. The National Institute of Standards and Technology (NIST) published its first finalized post-quantum cryptography standards in August 2024. Ledger's CTO, Charles Guillemet, recently walked through the implications of these new standards on Bitcoin, Ethereum, and hardware security.

NIST formalized two digital signature schemes: ML-DSA and SLH-DSA. The former uses lattice-based cryptography, while the latter relies on hash functions, a more conservative approach that doesn't require novel mathematical assumptions. However, Sphincs+ produces larger signatures, which could be problematic for blockchain transactions.

The Bitcoin and Ethereum communities are leaning towards SLH-DSA, citing their trust in established cryptographic primitives like SHA-256 and SHAKE. This divergence matters because a sufficiently powerful quantum computer could theoretically break elliptic curve cryptography used by both assets. Researchers are exploring optimized Sphincs+ variants for Ethereum, but this raises practical questions about storage costs and node economics.

Ledger is actively working on integrating post-quantum cryptography into its hardware wallet firmware, aiming to ship support for ML-KEM and ML-DSA by June 2026. This transition will require users to move funds to new addresses generated under the new cryptographic standards.