Signal fingerprinting for authentication of communicating devices

Aspects of the subject disclosure may include, for example, receiving electromagnetic waves at a physical interface of a transmission medium that propagate along the transmission medium without requiring an electrical return path, wherein the electromagnetic waves are guided by the transmission medium, and wherein the electromagnetic waves have a non-optical frequency range. A determination is made as to whether the electromagnetic waves are being received from a second network device according to a comparison of a fingerprint of the electromagnetic waves and an expected fingerprint of expected parameters for the electromagnetic waves transmitted by the second network device. Other embodiments are disclosed.