bergzand / sphss

Simple implementation of LMS/HSS signatures

sphss - Simple and Portable HSS signatures

Simple and portable implementation of LMS/HSS signatures. The code tries to make everything simple as possible to use LMS Hash Based Signature Scheme from RFC 8554.

Disclaimer: this version is reference only. It is not side-channel protected. Also, it is not optimized.

LMS/HSS Signatures

The code is a KISS (Keep it simple stupid) of LMS/HSS signatures. It is based entire in the RFC 8554.

FAST VERSION: https://github.com/gbanegas/sphss/tree/fast

How to run

-Select the best flavour in the Makefile, for example:

COMPILE_FLAGS = -DLMOTS_SHA256_N32_W8 -DLMS_SHA256_M32_H5

The other options for LMOTS are:

-DLMOTS_SHA256_N32_W1 

-DLMOTS_SHA256_N32_W2

-DLMOTS_SHA256_N32_W4 

-DLMOTS_SHA256_N32_W8 

The other options for LMS are:

-DLMS_SHA256_M32_H5

-DLMS_SHA256_M32_H10

-DLMS_SHA256_M32_H15

-DLMS_SHA256_M32_H20

-DLMS_SHA256_M32_H25

Then it is just call make:

foo@bar: make
foo@bar: ./sphss

Tests

Benchmark

Using cpucycle from Supercop, we reach the following values for COMPILE_FLAGS = -DLMOTS_SHA256_N32_W8 -DLMS_SHA256_M32_H5 (in an Intel(R) Core(TM) i7-10610U CPU @ 1.80GHz):

median lms-ots keygen: 7893243 cycles 
median lms-ots sign: 3907529 cycles 
median lms-ots verify: 3990474 cycles 
median lms keygen: 294766029 cycles 
median lms sign: 300630336 cycles 
median lms verify: 4644142 cycles 
median hss keygen: 838803787 cycles 
median hss sign: 283486422 cycles 
median hss verify: 8780359 cycles