Romulus AEAD - Light-weight cipher. Romulus is a light weight block cipher and was written by Tetsu Iwata, Mustafa Khairallah, Kazuhiko Minematsu and Thomas Peyrin [1][2]. The NIST competition for lightweight cryptography has reached the final stage, and with a shortlist of 10 candidates. Each differs in their approach, but they aim to create a cryptography method that is secure, has a low footprint, and is robust against attacks. So while many of the contenders, such as ASCON, GIFT and Isap, use the sponge method derived from the SHA-3 standard (Keccak), Romulus takes a more traditional approach and looks towards a more traditional light-weight crypto approach. Overall it is defined as a tweakable block cipher (TBC) and which supports authenticated encryption with associated data (AEAD). For its more traditional approach, it uses the SKINNY lightweight tweakable block cipher.