Ledger CTO: Post-Quantum Crypto Migration Enters Pivotal Phase, Blockchain Leans Towards Hash-Based Signature Scheme

BlockBeats News, April 23 - Ledger's Chief Technology Officer Charles Guillemet wrote in a post that "Post-Quantum Cryptography is entering a critical stage. While the timing of the emergence of quantum computers with practical cryptographic impact remains uncertain, the industry generally believes that the transition to post-quantum systems is inevitable. The traditional sector has established a clear timeline, led by the National Institute of Standards and Technology (NIST) of the United States, planning to phase out existing vulnerable algorithms by 2030 and fully disable them by 2035. Currently, large enterprises and government agencies are accelerating their preparations, aiming to complete the transition by 2029."

On the technical path, encryption and key exchange will transition to ML-KEM (formerly CRYSTALS-Kyber) to address the risk of "decrypt-then-collect" quantum attacks. However, in the blockchain ecosystem, the core issue is more focused on digital signatures. The current mainstream post-quantum signature schemes fall into two categories: lattice-based ML-DSA (formerly CRYSTALS-Dilithium) and hash-based SLH-DSA (formerly SPHINCS+). The traditional industry tends to adopt ML-DSA and hybrid schemes with ECC, while the blockchain sector leans towards hash-based signature schemes that prioritize security conservatism and simplicity of structure.

Each type of scheme has its own trade-offs: ML-DSA offers better performance but its security assumptions have not yet undergone long-term validation; SLH-DSA, although less efficient, relies on a mature hash function system, making its security more deterministic. For blockchains that emphasize long-term security and validation paths, the latter is more attractive. However, regardless of the chosen scheme, the compatibility of Multi-Party Computation (MPC) and Threshold Signatures remains a current unresolved challenge, with this risk being particularly critical in industries based on custodial and collaborative signatures."