Abstract

Much of the security of a block cipher based on the Feistel network depends on the properties of the substitution boxes (s-boxes) used in the round function. Although many desirable properties have been studied, relatively little work has been done to determine to what degree these properties are achievable in practice. This paper presents one effort to construct large, cryptographically secure s-boxes, contrasting theoretical and practical limitations, and highlighting areas for future research.

Citations