Layer 1 blockchain Sui has announced plans to introduce quantum-resistant security infrastructure on its mainnet within the year, deploying two post-quantum signature schemes approved by the National Institute of Standards and Technology (NIST). The initiative addresses the emerging threat that sufficiently powerful quantum computers could eventually compromise the elliptic-curve cryptography securing most blockchain accounts today.

The upgrade will integrate ML-DSA-65—a lattice-based scheme finalized by NIST as FIPS 204 in August 2024 under the name CRYSTALS-Dilithium—as a native protocol signature scheme for regular accounts, while the hash-based SLH-DSA-SHA2-128s, standardized as FIPS 205 and derived from SPHINCS+, will be implemented within Move smart contracts to protect high-value vaults. Post-quantum signatures are substantially larger than classical ones; ML-DSA-65 produces signatures exceeding 3,000 bytes compared with roughly 64 bytes for Ed25519, a tradeoff that affects block space and transaction throughput. Because Sui keys are derived deterministically from a seed, users will be able to transition to quantum-safe keys using their existing recovery phrases without creating new accounts.

Additionally, Sui's live address alias feature allows existing accounts to update their authorization keys directly, eliminating the need to transfer assets elsewhere. The network is targeting mainnet deployment of quantum-safe vaults this year, with native ML-DSA-65 accounts expected on testnet by year-end and mainnet authentication scheduled for the first quarter of 2027. These timelines remain provisional pending independent audits and testnet feedback.

Sui outlined the initiative in a post on X:

Making Sui quantum ready: Sui is adding two NIST-approved quantum-resistant signature schemes. One for everyday accounts, one for high-value Move vaults. Existing accounts can rotate to a quantum-safe key derived from their recovery phrase. Same address, and funds stay put.

— Sui (@SuiNetwork) August 6, 2026

Onchain Exposure and the Compressed Quantum Timeline

The urgency behind the upgrade stems from a fundamental property of public blockchains: public keys are permanently exposed from the moment an account transacts. This enables "harvest-now-forge-later" attacks, where adversaries collect encrypted data today to decrypt once quantum hardware matures. In March 2026, Google Quantum AI estimated that recovering a private key from an exposed public key could be accomplished in minutes on a fault-tolerant machine with fewer than 500,000 physical qubits.

Regulatory timelines have also accelerated. While NIST originally planned to deprecate classical algorithms by 2030 and disallow them by 2035, Executive Order 14412—signed in June 2026—requires federal agencies to adopt post-quantum key establishment by the end of 2030 and post-quantum digital signatures by the end of 2031. For blockchain networks, the migration challenge is compounded by the fact that cryptographic primitives are typically embedded in consensus rules, making changes far more complex than in traditional IT systems.

Sui's architecture was designed for cryptographic agility, allowing new signature schemes to be added without altering consensus or existing network state. This design choice enables the integration as a routine protocol update rather than a fundamental rebuild, positioning the network to adapt as quantum capabilities advance.