A (4:2) adder for unified GF (p) and GF (2n) Galois field multipliers

This paper describes a new redundant binary adder that supports carry-save additions under either of the Galois fields, GF(p) or GF(2/sup n/), without the need for an external control signal to specify which field is to be used. The proposed adder will find use in unified Galois field multipliers for cryptographic applications. Its main advantage over previously reported adders is that a control signal which is broadcast to all cells to suppress carries under GF(2/sup n/) is not needed, leading to a substantial gain in implementation efficiency.