Towards a Post-Quantum Matrix Protocol: A Hybrid Wrapper Adapted to the Brazilian Scenario
Paulo A L Rego, Gilvan Maia, Rodrigo Pacheco
This presentation outlines the development experience of a post-quantum cryptography (PQC) wrapper for the vodozemac library, tailored for its use in MSG
GOV, a Matrix-powered E2EE messenger for the Brazilian federal government. Our wrapper is designed to support multiple PQC algorithms, including ML-KEM and Brazil's state-mandated cryptography. The talk details the practical software engineering challenges associated with the hybrid integration of flexible PQC features into the Matrix protocol, extending both the key agreement and the Double Ratchet algorithm while maintaining backwards compatibility.