This repository is a fork of the SPHINCS+ repository. It is a slimmed down version of SPHINCS+ with custom parameters for security levels of 192 and 256-bits. It only uses the 'simple' SHA256 versions of SPHINCS+. The slim verifier links to OpenSSL and uses its SHA256 impelementation.
The parameters are in the ref/params folder and symbolic link is used from there in the ref diretory pointing to the right parameters file.
It includes testing code with a seperate signer and verifier that use three files to store the message the public key and the signature.
To build and run the separate signer and verifier you can run make sig-ver in the ref directory. To run the signer and verifier separately you can use make test/spx_sig-to-file.exec and make test/spx_slim-ver-from-file.exec in the ref directory. The slim verifier links to OpenSSL's SHA256 implementation. To run the slim verifier that includes its own SHA256 implementation (same API as OpenSSL but not linked to OpenSSL) use make test/spx_ver-from-file.exec. To run the bloated verifier that includes all code and djb's SHA256 implementation run make test/spx_bloated-ver-from-file.exec.
A new shell script called sw_sig_bench.sh runs the benchmark make benchmark in the ref and sha256-avx2 directories for the parameters in the ref/params.h file. The benchmark in ref uses OpenSSL's SHA256 implementation that includes ASM optimizations and performs better for verification. If OpenSSL is not present, then tweak the Makefile to use -DUSE_OPENSSL_API_SHA256 for a SHA256 implementation with the same API as OpenSSL or do not use any definitions in order to use djb's SHA256 implementation. The benchmark in sha256-avx2 is optimized and uses paralellization. It performs better for key generation and signing.
All included code is available under the CC0 1.0 Universal Public Domain Dedication.