ON THE AUTOMORPHISM GROUP OF SOME CLASSES OF SYSTEMATIC CODES
ABDELFATTAH HAILY *
Department of Mathematics, Faculty of Sciences, Chouaib Doukkali University, El Jadida, Morocco
DRISS HARZALLA
Department of Mathematics, Faculty of Sciences, Chouaib Doukkali University, El Jadida, Morocco
*Author to whom correspondence should be addressed.
Abstract
In several applications of algebraic coding theory and cryptography, we need only to compute an automorphism group of a linear code and not its full automorphism group which is known to be a hard problem. In this paper we give a more effective method for computing such a group of automorphisms of a systematic code C. In the particular case where [I|A] is a generator matrix of C and A is an involutory matrix the method described here can give important information about the full automorphism group and, in some cases, can even determine the full automorphism group. Numerical examples are given by use of some theoretical software tools such as GAP, Q-extension and Matlab.
Keywords: Systematic codes, equivalent code, automorphism group