Authentication is the process of confirming the legal identity of communicating entities, and it is the first line of defense for security communication. Most of the existing tag-based physical layer security authentication (PLSA) requires distributing the shared keys in advance. In the large scale internet of things scenario, nodes frequently join and leave the wireless networks that cause the distribution and management of keys particularly difficult. This paper proposes a tag-based PLSA scheme, which utilizes channel characteristics instead of distributing keys to generate authentication tags. Specifically, based on watermarking mechanism, we design a fault-tolerant hash algorithm to couple the secret sequence and the message signal for authentication tags generation. The shared secret sequence is generated by legitimate nodes through channel probing. And the theories of information theory and composite hypothesis testing is employed to analyze the performance of system. The simulation results show that the agreement ratio of the generating shared secret sequence is as high as 96% in the case of high signal-to-noise ratio and low power tag embedding. In addition, performance analysis demonstrates the scheme can resist against multiple attacks, such as replay, jamming, tampering, and impersonation attack.INDEX TERMS Authentication, wireless network, tag-based, hash algorithm, channel probing.