SPHINCS+

This repository contains the software that accompanies the SPHINCS+ submission to NIST's Post-Quantum Cryptography project.

Parameters

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

License

All included code has been placed into Public Domain and is available under various open source licenses (Creative Commons Zero v1.0 Universal (CC0-1.0), BSD Zero Clause License (0BSD), and MIT No Attribution (MIT-0), see the LICENSE file and the licenses in the LICENSES folder), with the exception of rng.c, rng.h and PQCgenKAT_sign.c, which were provided by NIST, and parts of ref/haraka.c, which are under MIT license (MIT).