Sui to Add NIST-Approved Quantum-Resistant Signatures, Enable Migration With Existing Recovery Phrases

Sui, the blockchain network, plans to add two quantum-resistant signature schemes approved by the US National Institute of Standards and Technology, or NIST, to address threats from quantum computing.

The network plans to integrate ML-DSA-65 for standard accounts and SLH-DSA-SHA2-128s for safeguarding high-value assets inside smart contracts, The Block reported on August 6. Both schemes are approved under NIST's Federal Information Processing Standards, or FIPS.

Sui said public keys in on-chain environments are permanently exposed once an account executes even a single transaction. A sufficiently powerful quantum computer running Shor's algorithm could eventually break the elliptic curve cryptography that protects most on-chain accounts today. The company also described so-called "harvest now, decrypt later" attacks as a realistic threat, in which attackers collect public keys now and exploit them once quantum computers become practical.

For standard accounts, Sui chose ML-DSA-65 at security level 3. The company said it rejected the cheaper level 1 option after an artificial intelligence model in July cut the effective key strength of another candidate quantum-resistant algorithm in half. ML-DSA was unaffected, but Sui said the pace of such progress made it reasonable to adopt a standard with more margin than the minimum requirement.

SLH-DSA-SHA2-128s, which will be used inside smart contracts, is a hash-based scheme. Because the two systems rely on different mathematical principles, a vulnerability in one would not affect the other.

Sui also emphasized user convenience. Because Sui keys are generated deterministically from a seed, users can migrate to quantum-resistant keys using only their existing recovery phrases. The network's address alias feature also lets users replace the authentication key for an existing account without moving assets.

Sui said the update is a standard protocol feature addition that does not alter consensus or the existing state. Existing services and applications do not need to make any immediate changes. Quantum-resistant vaults are scheduled for mainnet deployment this year. Standard accounts based on ML-DSA-65 are targeted for testnet by the end of 2026, with mainnet rollout planned for the first quarter of 2027.