On the security of designing a Cellular Automata based stream cipher

Abstract

Over the years Cellular Automata (CA) have been getting importance as a better crypto-primitives in designing stream ciphers. Wolfram identified Rule 30 as a powerful nonlinear function for cryptographic applications. However, Rule 30 CA is vulnerable against Meier and Staffelbach (MS) attack. This paper analyzes maximum period nonlinear CA (M-NHCA) which is shown to be secure against MS attack. We present a new design construction of a stream cipher employing the maximum period nonlinear CA and linear CA in conjunction with a rotational symmetric bent function. The proposed cipher has also been analyzed in aspect of almost all the known attacks in particular, the fault attack against which most of the eStream candidates like Grain-128 are vulnerable.