Efficient message authentication for spread spectrum wireless communications

In this paper we present a new scheme to reduce the communications requirements to send message authentication tags (MAC's), by sending the MACs over direct sequence spread spectrum wireless channels. We greatly reduce the number of chips required by considering the chip sequence as a whole. In one example, based on the IS-95 CDMA Digital Cellular Standard, we reduce the chips needed from 3072 to 1142 by a hard decision decoding scheme, and to 728 by a soft decision decoding scheme, achieving savings of factors about three and four, respectively.