Sui says it will add two post-quantum signature schemes approved by the US National Institute of Standards and Technology as part of a broader effort to reduce the long-term cryptographic risks facing blockchain accounts and smart contracts.

According to the plan, ML-DSA-65 will be introduced for standard accounts, while SLH-DSA-SHA2-128s will be used to protect high-value assets held inside smart contracts. The network said users will be able to migrate using their existing recovery phrases, and that the change will not require a consensus overhaul or immediate updates from applications and services.

Why Sui says the change is needed

Sui described public-key exposure as a structural issue for blockchains. Once an account sends even a single transaction, its public key is permanently visible on-chain, which means that any future weakness in the signature system could affect previously active accounts.

The network said a sufficiently capable quantum computer running Shor's algorithm could eventually break the elliptic curve cryptography widely used by on-chain accounts today. It also pointed to the risk of "harvest now, decrypt later" strategies, where attackers gather public keys in advance and wait for quantum computing to become practical enough to exploit them.

Two different schemes for two different roles

For ordinary user accounts, Sui plans to adopt ML-DSA-65 at security level 3. The company said it did not choose the less costly level 1 option, arguing that recent advances justified building in more security margin than the minimum standard would require.

Sui cited an incident in July in which an artificial intelligence model reportedly reduced the effective key strength of another post-quantum algorithm candidate by half. It said ML-DSA was not affected, but presented that development as part of the reason for preferring a stronger setting.

For smart contracts holding higher-value assets, Sui plans to use SLH-DSA-SHA2-128s, a hash-based signature scheme. Because it rests on different mathematical assumptions from ML-DSA, Sui said a flaw in one system would not automatically compromise the other.

Migration path and impact on existing apps

A central part of the rollout is backward compatibility for users. Sui said its keys are derived deterministically from a seed, allowing users to move to quantum-resistant keys with the same recovery phrases they already have.

The network also pointed to its address alias mechanism, which lets an account replace its authentication key without transferring assets to a new address. That approach is intended to simplify migration and reduce operational friction.

Sui characterized the update as a standard protocol feature addition rather than a consensus change. It said the update will not modify the existing chain state, and that applications and services do not need to make immediate technical changes.

Deployment timeline

The first planned milestone is quantum-resistant vaults on mainnet later this year. Those vaults are intended for smart-contract-based protection using the SLH-DSA-SHA2-128s scheme.

For standard accounts using ML-DSA-65, Sui is targeting testnet availability by the end of 2026. Mainnet rollout for those accounts is planned for the first quarter of 2027.

The timeline indicates that the network will introduce post-quantum protections in stages, starting with contract-based vaults and then extending the feature set to regular accounts.

Source: en.bloomingbit.io