This repository contains the software that accompanies the SPHINCS+ submission to NIST's Post-Quantum Cryptography project.
The SPHINCS+ specification proposed a set of 36 named instances, specifying hash functions and concrete parameters for the security level, tree dimensions, WOTS+ and FORS. This reference implementation allows for more flexibility, as parameters can be specified in a params.h file. The proposed parameter sets have been predefined in ref/params/params-*.h, and the hash function can be varied by linking with the different implementations of hash.h, i.e., hash_haraka.c, hash_sha2.c and hash_shake.c, as well as different implementations of thash.h, i.e., *_robust.c and *_simple.c. This is demonstrated in the Makefile. See the table below for a summary of the parameter sets. These parameters target the NIST security categories 1, 3 and 5; for each category, there is a parameter set geared towards either small signatures or fast signature generation.
| n | h | d | log(t) | k | w | bit security | pk bytes | sk bytes | sig bytes | |
|---|---|---|---|---|---|---|---|---|---|---|
| SPHINCS+-128s | 16 | 63 | 7 | 12 | 14 | 16 | 133 | 32 | 64 | 7,856 |
| SPHINCS+-128f | 16 | 66 | 22 | 6 | 33 | 16 | 128 | 32 | 64 | 17,088 |
| SPHINCS+-192s | 24 | 63 | 7 | 14 | 17 | 16 | 193 | 48 | 96 | 16,224 |
| SPHINCS+-192f | 24 | 66 | 22 | 8 | 33 | 16 | 194 | 48 | 96 | 35,664 |
| SPHINCS+-256s | 32 | 64 | 8 | 14 | 22 | 16 | 255 | 64 | 128 | 29,792 |
| SPHINCS+-256f | 32 | 68 | 17 | 9 | 35 | 16 | 255 | 64 | 128 | 49,856 |
All included code is available under the CC0 1.0 Universal Public Domain Dedication, with the exception of rng.c, rng.h and PQCgenKAT_sign.c, which were provided by NIST.