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 run2026-09-21 11:47 UTC
commit6ed429a
CPU
Xeon Platinum 8488C
Measured on
c7i.large
OS / Kernel
24.04.4 LTS
liboqs
0.15.0
Wall clock
32m 32s
CPU steal
<0.01%

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.

keygenGenerate a fresh key pair.
131 of 131 runs
Mean
111.54 ms
95% CI on mean
±0.03%
Median
111.48 ms
p95
112.20 ms
p99
113.34 ms
Stdev
524.2 µs
Min
110.57 ms
Ops/sec
9.0

Mean is known to 111505.06–111570.04 µs across 1,000 iterations. A 95% confidence interval on the mean, not a prediction interval for a single operation. It says how precisely the average is known from this run's samples; the standard deviation says how much the individual samples scattered.

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.
131 of 131 runs
Mean
850.80 ms
95% CI on mean
±0.01%
Median
850.65 ms
p95
853.06 ms
p99
855.58 ms
Stdev
1.48 ms
Min
846.77 ms
Ops/sec
1.2

Mean is known to 850704.74–850888.05 µs across 1,000 iterations. A 95% confidence interval on the mean, not a prediction interval for a single operation. It says how precisely the average is known from this run's samples; the standard deviation says how much the individual samples scattered.

Mean over time

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

verifyVerify a signature against a message and public key.
131 of 131 runs
Mean
852.1 µs
95% CI on mean
±0.35%
Median
849.7 µs
p95
909.8 µs
p99
941.3 µs
Stdev
47.8 µs
Min
755.6 µs
Ops/sec
1,174

Mean is known to 849.10–855.03 µs across 1,000 iterations. A 95% confidence interval on the mean, not a prediction interval for a single operation. It says how precisely the average is known from this run's samples; the standard deviation says how much the individual samples scattered.

Mean over time

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

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