SLH-DSA
The Stateless Hash-Based Digital Signature Algorithm, standardised by NIST as FIPS 205 in August 2024 from SPHINCS+. Its security rests on hash functions alone, at the cost of large signatures.
- Quantum status
- Believed quantum-resistant
- Standard
- FIPS 205, final
- Family
- hash based stateless
- Also known as
- SPHINCS+, FIPS 205
Rated chains using it
- Aptos Specified, not deployed
Account signatures, SLH-DSA-SHA2-128s. Opt-in alongside Ed25519 under AIP-137, accepted April 2026. Merged and enabled on devnet only (feature flag 107); off on testnet and mainnet as read on 22 October 2026. Source code or release
- IOTA Mainnet, opt-in
Identity layer. IOTA Identity v1.7 credentials, not layer-1 transactions. Specification or proposal
- Nervos CKB Mainnet, opt-in
Account signatures, SPHINCS+, twelve parameter sets. Through an audited lock script. Specification or proposal
- Sui Proposed
Contract level, SLH-DSA-SHA2-128s. Smart contract vaults. Statement or write-up
Sources
- FIPS 205: Stateless Hash-Based Digital Signature Standard , NIST. Accessed 19 October 2026.
Published beside the Hardy Score and not an input to it. How each chain is scored is set out in the methodology.