Software Evaluation of Grain-128AEAD for Embedded Platforms

Grain-128AEAD is a stream cipher supporting authenticated encryption
with associated data, and it is currently in round 2 of the NIST lightweight crypto
standardization process. In this paper we present and benchmark software implementations of the cipher, targeting constrained processors. The processors chosen are
the 8-bit (AVR) and 16-bit (MSP) processors used in the FELICS-AEAD framework.
Both high speed and small code size implementations are targeted, giving us in total
4 different implementations. Using the FELICS framework for benchmarking, we
conclude that Grain-128AEAD is competitive to other algorithms currently included
in the FELICS framework. Our detailed discussion regarding particular implementation tricks and choices can hopefully be of use for the community when considering
optimizations for other ciphers.