Authenticated Encryption Based on Lesamnta-LW Hashing Mode

Abstract

Authenticated encryption refers to symmetric cryptography providing both privacy and authenticity. It is most common to construct it as a block-cipher mode of operation. Another promising approach is to construct it based on cryptographic hashing. This paper proposes a nonce-based authenticated encryption scheme based on the Lesamnta-LW hashing mode. Lesamnta-LW is a block-cipher-based iterated hash function, which is specified in the ISO/IEC 29192-5 lightweight hash-function standard. This paper also shows that the proposed scheme is secure if the underlying block cipher is a pseudorandom permutation. Both of the other ISO/IEC 29192-5 mechanisms, PHOTON and SPONGENT, are hardware-oriented sponge-based hash functions, and nonce-based authenticated encryption schemes can also be constructed based on them. On the other hand, Lesamnta-LW is a software-oriented Merkle-Damgård hash function. Thus, the proposed scheme is a new option for authenticated encryption based on lightweight cryptographic hashing.