Security Evolution on the Non-linear Part of SNOW2.0 against Guess and Determine Attack
Hao Hu, Jianjun Lu · 2017
SNOW 2.0 was proposed by Ekdahl and Johansson as a strengthened version of SNOW 1.0, which was submitted to the NESSIE project, with a variable-length key of 256 bits. The designers of SNOW2.0 improved the resistance against Guess and Determine (GD) attack by introducing two inputs to the Finite State Machine (FSM). In this paper, the results show that the introduction of those two inputs is not optimal. The suggestion on improving the resistance against GD attack for SNOW2.0 is given.