Ledger CTO: Post-Quantum Cryptography Migration Enters Critical Phase, Blockchain Favors Hash-Based Signatures

Gate News message, April 23 — Ledger Chief Technology Officer Charles Guillemet outlined the current state of post-quantum cryptography migration, stating that the industry has reached a critical juncture. While the timeline for quantum computers with practical cryptographic impact remains uncertain, migration to post-quantum systems is considered inevitable. Traditional sectors have established clear timelines led by the U.S. National Institute of Standards and Technology (NIST), targeting the elimination of vulnerable algorithms by 2030 and complete prohibition by 2035. Major enterprises and government agencies are accelerating preparations to complete migration capabilities by 2029.

On the technical path, encryption and key exchange will shift to ML-KEM (formerly CRYSTALS-Kyber) to address “harvest now, decrypt later” quantum attacks. For blockchain systems, the focus centers on digital signatures. Current post-quantum signature schemes fall into two categories: lattice-based ML-DSA (formerly CRYSTALS-Dilithium) and hash-based SLH-DSA (formerly SPHINCS+). Traditional industries favor ML-DSA and hybrid approaches combining it with ECC, while blockchain favors hash-based schemes for their conservative security assumptions and simpler architecture.

Each approach involves trade-offs: ML-DSA offers better performance but its security assumptions lack long-term verification; SLH-DSA has lower efficiency but relies on mature hash function systems with greater security certainty. For blockchains emphasizing long-term security and validated pathways, the latter holds greater appeal. However, compatibility between multi-party computation (MPC) and threshold signatures remains an unresolved challenge, presenting particular risks in industries built on custody and collaborative signing.