June 20, 2021


Dedicated Forum to help removing adware, malware, spyware, ransomware, trojans, viruses and more!

Grain-128AEADv2: Strengthening the Initialization Against Key Reconstruction, by Martin Hell and Thomas Johansson and Alexander Maximov and Willi Meier and Hirotaka Yoshida

Properties of the Grain-128AEAD key re-introduction, as part of the cipher initialization, are analyzed and discussed. We consider and analyze several possible alternatives for key re-introduction and identify weaknesses, or potential weaknesses, in them. Our results show that it seems favorable to separate the state initialization, the key re-introduction, and the $A/R$ register initialization into three separate phases. Based on this, we propose a new cipher initialization and update the cipher version to Grain-128AEADv2. It can be noted that previously reported and published analysis of the cipher remains valid also for this new version.