Syndrome Decoding in the Head (SDitH) is an MPC-in-the-Head signature whose security reduces to the classical syndrome decoding problem over random linear codes.
Key parameters
spec snapshot- Hard problem
- Syndrome Decoding (random linear codes)
- Framework
- MPC-in-the-Head (hypercube variant)
- Public key size
- ~120 B
- Signature size
- ≈ 8,241 B (L1 fast variant)
- NIST security levels
- I, III, V
NIST citations
3 sourcesRound timeline
4 events · 2023 → 2027- Round 1
Submission accepted
Included in the 40-candidate cohort for the additional-signatures on-ramp.
- Round 2
Advanced to Round 2
NIST selected 14 candidates for continued analysis (IR 8528).
- Round 3
Advanced to Round 3
Down-selected to 9 candidates for the final evaluation round.
- Round 3
7th NIST PQC Standardization Conference
Scheduled late spring / early summer 2027, Gaithersburg, MD.
Source: NIST CSRC · IR 8610 (Round 3 advancement, May 14, 2026) · IR 8528 (Round 2 advancement, Oct 24, 2024).