A Novel Algorithm of Constructing Highly Nonlinear S-p-boxes

On the Diiculty of Constructing C R Y P T Ographically Strong S U Bstitution Boxes

Two signi cant recent advances in cryptanalysis namely the di erential at tack put forward by Biham and Shamir BS and the linear attack by Matsui Mat a Mat b have had devastating impact on data encryption algorithms An eminent prob lem that researchers are facing is to design S boxes or substitution boxes so that an encryption algorithm that employs the S boxes is immune to the attacks In this ...

Construction of Highly Nonlinear Injective S-boxes With Application to CAST-like Encryption Algorithms

In this paper we present two methods for constructing highly nonlinear injective s-boxes. Both of these methods, which are based on exponential sums, outperform previously proposed methods. In particular, we are able to obtain injective 8 32 s-boxes with nonlinearity equal to 80 and maximum XOR table entry of 2. We also re-evaluate the resistance of the CAST-like encryption algorithms construct...

Constructing S-boxes for Lightweight Cryptography with Feistel Structure

On Highly Nonlinear S-Boxes and Their Inability to Thwart DPA Attacks

Prouff has introduced recently, at FSE 2005, the notion of transparency order of S-boxes. This new characteristic is related to the ability of an S-box, used in a cryptosystem in which the round keys are introduced by addition, to thwart single-bit or multi-bit DPA attacks on the system. If this parameter has sufficiently small value, then the S-box is able to withstand DPA attacks without that...

On the Number Of Nonlinear Regular S-boxes

A. M. Youssef and S. E. Tavares Department Of Electrical and Computer Engineering Queen’s University Kingston, Ontario, Canada, K7L 3N6 Phone : (613) 545–2945 Fax : (613) 545–6615 email : [email protected] Indexing terms: Cryptography, Private-key cryptosystems, Substitution boxes, Combinatorics. Abstract Nonlinearity is a crucial requirement for the substitution boxes in secure block ciphe...