Sui Adopts Post-Quantum Signature Schemes to Enhance Quantum Readiness

Sui announced the adoption of two post-quantum signature schemes as part of its strategy to prepare for quantum computing threats. The blockchain is implementing the schemes to enable accounts to migrate to quantum-safe keys derived from recovery phrases users already hold.

The timing matters for blockchains because public keys are permanently exposed onchain from the moment an account transacts. Unlike traditional systems where attackers typically need a breach to access keys, onchain keys are visible to all. Shor's algorithm can theoretically break the elliptic-curve cryptography securing most blockchain accounts today. A technique called harvest-now-forge-later does not require quantum hardware to be dangerous—it only requires a visible key and patience, as exposure accumulates over time. According to the article, Google Quantum AI estimated in March 2026 that this specific attack could succeed in minutes on a fault-tolerant quantum machine with fewer than half a million physical qubits.

Sui chose to adopt two signature schemes based on different mathematical foundations rather than committing to a single algorithm, reducing the risk that a weakness in one approach would compromise security. Both schemes follow NIST's standardized post-quantum algorithms and align with the quantum-readiness roadmap jointly developed by CISA, NSA, and NIST.

The network's design allows new signature schemes to be added without requiring changes to consensus mechanisms or existing state. The implementation focuses on practical migration: an ML-DSA-65 private key is a 32-byte seed matching the size stored in today's wallets, derived from the same recovery phrase through a new derivation path. Existing accounts have a migration path that does not require moving funds, supported by address aliases already deployed on Sui.