New cryptanalytic results on the effect of invariance weakness in the KSAm mechanism
Bogdan Crainicu, Adam Mihai Gergely · 2017
In this paper we review the proposed RC4 key scheduling algorithm called KSAm, and we present new cryptanalytic results concerning the effect of the Fluhrer-Mantin-Shamir invariance weakness on KSAm. Taking into account that the KSAm can be integrated within the entire class of known-plaintext attack resistant stream ciphers, whose design is based on the Knuth Fisher-Yates principle for generating a random permutation of a finite sequence in order to obtain a random distribution for the elements of cipher's internal states, we derive probabilistic bounds that formalize this effect on the overall KSAm mechanism.