10-12-2012, 02:31 PM
The Structured Design of Cryptographically Good S-Boxes
The Structured Design of.pptx (Size: 209.19 KB / Downloads: 25)
ABSTRACT
To construct s-boxes which are
Bijective , highly nonlinear, possess
the strict avalanche criterion , and
have output bits which act (virtually)
independently when any single input
bit is complemented.
KEYWORDS
Cryptography
S-boxes,
Boolean functions,
Nonlinearity,
Strict avalanche criterion.
Introduction
WHY S BOXES DESIGN ?
S-BOX is the only nonlinear part of the cryptosystem(DES) .
Good design of S-box can prevent breaking of the cryptosystem.
Here 4 properties are described to which a good s-box should posses.
Purpose
Our purpose is to find a functionf1,f2,…..fn for the output of s box such that the corresponding s box isbijective, nonlinear and fullfill theSAC( Strict Avalenche Criteria) and BIC(Bit Independent Criteria).