ef, Message Authentication message authentication is concerned with protecting the integrity of a message validating identity of originator non-repudiation of origin(dispute resolution) will consider the security requirements then three alternative functions used message encryption message authentication code( MAC) hash function 復大辱软件学院8 Message Authentication • message authentication is concerned with: – protecting the integrity of a message – validating identity of originator – non-repudiation of origin (dispute resolution) • will consider the security requirements • then three alternative functions used: – message encryption – message authentication code (MAC) – hash function