Koç and Sunar proposed an architecture of the Mastrovito multiplier for the irreducible trinomial$f(x)=x^{n}+x^{k}+1$, where$k\neq n/2$to reduce the time complexity. Also, many multipliers based on the Karatsuba-Ofman algorithm (KOA) was proposed that sacrificed time efficiency for low space complexity. In this paper, a new multiplication formula which is a variant of KOA presented. We also provide a straightforward architecture of a non-pipelined bit-parallel multiplier using the new formula. The proposed multiplier has lower space complexity than and comparable time complexity to previous Mastrovito multipliers' for all irreducible trinomials.

The efficient computation of the arithmetic operations in finite fields is closely related to the particular ways in which the field elements are presented. The common field representations are a polynomial basis representation and a normal basis representation. In this paper, we introduce a nonconventional basis and present a new bit-parallel multiplier which is as efficient as the modified Massey-Omura multiplier using the type I optimal normal basis.

It is well-known that a class of finite fields GF(2/sup n/) using an optimal normal basis is most suitable for a hardware implementation of arithmetic in finite fields. In this paper, we introduce composite fields of some hardware-applicable properties resulting from the normal basis representation and the optimal condition. We also present a hardware architecture of the proposed composite fields including a bit-parallel multiplier.