On the baseband communication performance of physical layer steganography

In this paper we explore the possibility of sending a steganographically hidden message through a digital communication channel. We view the hidden (embedded) information as additional noise added to a cover message, in conjunction with the inherent additive white Gaussian noise (AWGN). We use the bit error rate as a function of signal-to-noise ratio, and investigate whether the hidden message is truly steganographic in the sense that it cannot be distinguished from the usual noise in the channel. In addition we show that the hidden message is harder to detect when the information is encoded with an error-correcting code, and we present limits on the steganographic payload.