  For physical-layer authentication, the authentication tags are often sent
concurrently with messages without much bandwidth expansion. In this paper, we
present a channel coding approach for physical-layer authentication. The
generation of authentication tags can be formulated as an encoding process for
an ensemble of codes, where the shared key between Alice and Bob is considered
as the input and the message is used to specify a code from the ensemble of
codes. Then, we show that the security of physical-layer authentication schemes
can be analyzed through decoding and physical-layer authentication schemes can
potentially achieve both information-theoretic and computational securities.
