Paper 2020/1445

Observations on COMET

Daniel J. Bernstein and Henri Gilbert and Meltem Sonmez Turan

Abstract

This note presents two attacks against COMET, a second-round candidate in the NIST lightweight cryptography standardization process. The first attack uses a long message to detect the use of weak keys, whereas the second attack focuses on the resistance of COMET against slide attacks. These attacks do not invalidate the security claims of the designers.