This paper proposes a lightweight authenticated encryption (AE) scheme, called Light-OCB, which can be viewed as a lighter variant of the CAESAR winner OCB as well as a faster variant of the high profile NIST LWC competition submission LOCUS-AEAD. Light-OCB is structurally similar to LOCUS-AEAD and uses a nonce-based derived key that provides optimal security, and short-tweak tweakable blockcipher (tBC) for efficient domain separation. Light-OCB improves over LOCUS-AEAD by reducing the number of primitive calls, and thereby significantly optimizing the throughput. To establish our claim, we provide FPGA hardware implementation details and benchmark for Light-OCB against LOCUS-AEAD and several other well-known AEs. The implementation results depict that, when instantiated with the tBC TweGIFT64, Light-OCB achieves an extremely low hardware footprint - consuming only around 1128 LUTs and 307 slices (significantly lower than that for LOCUS-AEAD) while maintaining a throughput of 880 Mbps, which is almost twice that of LOCUS-AEAD. To the best of our knowledge, this figure is significantly better than all the known implementation results of other lightweight ciphers with parallel structures.
11th International Conference on Security, Privacy and Applied Cryptographic Engineering
2021-12-10
2022-03-02 10:46:06