Paper 2020/108

Practical Forgeries for ORANGE

Christoph Dobraunig and Florian Mendel and Bart Mennink

Abstract

We analyze the authenticated encryption algorithm of ORANGE, a submission to the NIST lightweight cryptography standardization process. We show that it is practically possible to craft forgeries out of two observed transmitted messages that encrypt the same plaintext. The authors of ORANGE have confirmed the attack, and they discuss a fix for this attack in their second-round submission of ORANGE to the NIST lightweight cryptography competition.