RAMESSES, a Rank Metric Encryption Scheme with Short Keys
This work provides a potential post-quantum secure encryption method for cryptographic applications, though it appears incremental as it builds on existing rank metric approaches.
The authors tackled the problem of designing a post-quantum encryption scheme with compact keys and ciphertexts, resulting in a rank metric code-based system that achieves sizes comparable to isogeny-based cryptography while offering efficient linear algebra operations and precise control over failure probability.
We present a rank metric code-based encryption scheme with key and ciphertext sizes comparable to that of isogeny-based cryptography for an equivalent security level. The system also benefits from efficient encryption and decryption algorithms, which rely on linear algebra operations over finite fields of moderate sizes. The security only relies on rank metric decoding problems, and does not require to hide the structure of a code. Based on the current knowledge, those problems cannot be efficiently solved by a quantum computer. Finally, the proposed scheme admits a failure probability that can be precisely controlled and made as low as possible.