Ciphertext Compression Techniques for Post-Quantum KEMs

In this work, we first provide a simple and efficient generic construction of mKEM that can be instantiated from versatile assumptions, including post-quantum ones. We then study these mKEM instantiations at a practical level using 8 post-quantum KEMs and show that compared to the trivial solution, our mKEM offers savings of at least one order of magnitude in the bandwidth.