Cryptographer's Toolkit for Construction of 8-Bit Bent Functions

Boolean functions form basic building blocks in various cryptographic algorithms. They are used for instance as filters in stream ciphers. Maximally non-linear (necessarily non-balanced) Boolean functions with an even number of variables are called bent functions. Bent functions can be modified to get balanced highly non-linear Boolean functions. Recently the first author has demonstrated how bent functions can be studied in a recursive framework of certain integer-valued functions. Based on this new approach we describe the practical systematic construction of 8-bit bent functions. We outline also how to compute the number of all 8-bit bent functions.