Patent ID: 6343305
Filing Date: 2002-01-29
Classification: G06F

Abstract:
A method of coding a digital data block represented as an element A of a finite Galois field GF(2m), wherein m is an integer, using multiplication of the element A and an element B of GF(2m) to produce a product C, the element A having coefficients aâ€²=(aâ€²1, . . . , aâ€²m) in an optimal normal basis, the method comprising:rearranging the coefficients aâ€² to determine coefficients a=(a1, . . . , a m) of the element A in a modified basis (&agr;,&agr;2, . . . , &agr;m), wherein &agr; is an element of GF(2m); and determining coefficients c=(c1, . . . , cm) of the product C in the modified basis, the coefficients c being equal to cl=&Sum;j=1m-l&it;(aj&it;bj+l+aj+l&it;bj)+&Sum;j=1l-1&it;aj&it;bl-j+&Sum;j=1l&it;am-l+j&it;bm-j+1,wherein b=(b1, . . . , bm) are coefficients of the element B in the modified basis and j, l, m are integers such that 1&lE;i, j,l&lE;m.