Design criteria of a new code-based KEM

The advances in quantum technologies became a threat to cryptosystems based on number-theoretic approach. Therefore, the development of post-quantum algorithms is currently underway. One of the areas of research is key encapsulation mechanisms (KEMs), which are supposed to replace the Diffie–Hellman key exchange protocol. When constructing such mechanisms, a modular approach based on a public key cryptosystem is often used. We provide an overview of such approaches for schemes based on error-correcting codes. We present arguments for and against the choice of each component of the modular approach. Moreover, we propose the combinations allowing to build KEMs with most favorable characteristics and present a proof of security for one of them.