SLH-DSA·Digital signature·NIST level 1

SLH-DSA-SHAKE-128s

SLH-DSA (FIPS 205) is a stateless hash-based signature scheme, standardized by NIST in August 2024. It relies only on the security of cryptographic hash functions — no number-theoretic assumptions. Larger signatures and slower signing, but the most conservative security basis.

The “s” (small) variant optimizes for signature size at the cost of signing speed — note the sign time is measured in seconds, not microseconds. Choose the “f” (fast) variant when signing throughput matters more than signature size.

Latest run2026-08-22 06:30 UTC

commit7e3d474

CPU: Xeon Platinum 8259CL @ 2.50GHz
Instance: t3.mediumburstable
OS / Kernel: 24.04.4 LTS
liboqs: 0.15.0
Wall clock: 54m 10s
CPU steal: 6.9%

Parameters

Family: SLH-DSA
Parameter set: SHAKE-128s
Public key: 32 B
Private key: 64 B
Signature: 7.67 KB
Iterations / op: 1,000
liboqs key: SLH_DSA_PURE_SHAKE_128S

Regulatory approval status

Whether this algorithm family is approved/recommended for use under three regimes. Every badge links to its source — click through before citing this elsewhere.

CNSA 2.0 (US/NSA)Not addressed

SLH-DSA is not named as a CNSA 2.0 requirement (ML-DSA is the mandated lattice signature; LMS/XMSS/ML-DSA-87 cover the stateful/firmware case — see the LMS/XMSS row).

NSA CNSA 2.0 Cybersecurity Advisory · not directly verified this session, spot-check the source

BSI TR-02102-1 (DE)Recommended

"Relevant and conservative option" per ANSSI's own cross-reference to BSI's aligned position; also covered under BSI §5.3.4.

BSI TR-02102-1, Version 2026-01 · not directly verified this session, spot-check the source

ANSSI (FR)Recommended

"Relevant and conservative option" for contexts that can afford SPHINCS+/SLH-DSA's larger signatures; hybridization optional; the XMSS/LMS state-handling recommendations apply here too.

ANSSI views on the Post-Quantum Cryptography transition (2023 follow up), §2

keygenGenerate a fresh key pair.

100 of 100 runs

Mean: 183.93 ms
Median: 175.05 ms
p95: 215.80 ms
p99: 321.15 ms
Stdev: 43.24 ms
Min: 167.16 ms
Ops/sec: 5.4

Mean over time

Click any point to view the GitHub Actions run that produced it.

signProduce a signature over a message using the private key.

100 of 100 runs

Mean: 1.415 s
Median: 1.353 s
p95: 1.649 s
p99: 2.835 s
Stdev: 240.30 ms
Min: 1.296 s
Ops/sec: 0.71

Mean over time

Click any point to view the GitHub Actions run that produced it.

verifyVerify a signature against a message and public key.

100 of 100 runs

Mean: 1.43 ms
Median: 1.32 ms
p95: 1.89 ms
p99: 2.88 ms
Stdev: 490.3 µs
Min: 1.13 ms
Ops/sec: 701

Mean over time

Click any point to view the GitHub Actions run that produced it.