Experimental Post-Quantum Crypto Support for CHERIoT

This repository contains experimental support for post-quantum encryption algorithms adapted to CHERIoT. The implementations are unmodified from the Linux Foundation's pq-code-package/mldsa-native and pq-code-package/mlkem-native packages. They have been wrapped to build as CHERIoT libraries.

This provides implementations of ML-KEM (FIPS 203) and ML-DSA (FIPS 204). Both depend internally on SHA3 (FIPS 202).

Experimental APIs

Currently, the two libraries expose the underlying APIs. These are not ideally adapted for CHERIoT and are subject to change.

Currently, both the ML-KEM and ML-DSA include a SHA3 implementation but neither exposes it. Hopefully a future version will separate this out and expose SHA3 functionality directly.

Future changes will also allow using heap instead of stack memory.

The current version implements only a shared library for the PQC algorithms. This means key management and so on are entirely the responsibility of the caller. A future version will wrap keys in sealed capabilities.

Note on stack usage

Both implementations currently use a lot more stack space than most embedded targets provide. A typical CHERIoT thread stack is under 2 KiB. The ML-KEM implementation uses around 18 KiB (slightly more for decryption than encryption). The ML-DSA implementation uses around 60 KiB to sign and around 48 KiB to