This repository contains an implementation of Sphincs+ which is designed to be HSM friendly. In particular, it minimizes the amount of RAM used. On my computer, it can generate or verify a Sphincs+ signature, or generate a public/private keypair (SHA2-28F-SIMPLE) with just 1k of RAM.

It achieves this low RAM uses (far smaller than the actual size of the signature) by streaming the signature; it can generate the signature (or read the signature on verify) in pieces (possibly even as small as 1 byte at a time), and so we don't need the RAM to hold the entire signature.

See the read.me and ramspace.out for more details