Physical Sciences and Mathematics Commons^™

Improvements To Correlation Attacks Against Stream Ciphers With Nonlinear Combiners, Brian Stottler

Mathematical Science: Student Scholarship & Creative Works

Our paper describes a particular class of digital cipher system that generates encryption keys using "linear feedback shift registers" (LFSRs) and nonlinear Boolean functions. In it, we review the details of such systems and the existing cryptanalysis methods used to recover secret keys and break the corresponding encryption. We also introduce a method for maximizing the statistical power of these attacks, alongside a novel attack method that makes use of a property of Boolean functions that we define and analyze.