Wireless communications’ infrastructures are frequently selected as a cable replacement in many applications, giving an immediate advantage on the wireless investment. However, the worldwide proliferation of wireless local area network (WLAN) imposed large investments on the network security. In the early days of the Internet, its layered protocol stack did not consider security as a primary concern. Since then a significant amount of literature has been published. This chapter proposes a watermark‐based blind physical layer security (WBPLSec) utilizing a jamming receiver in conjunction with the spread spectrum watermarking technique. The outage probability of the secrecy capacity is analytically derived, regardless of the eavesdropper position. The theoretical analysis let us draw a secure region around the legitimate receiver. Results indicate how the WBPLSec aims to be a valuable technique for deploying physical layer security. Authors utilized the outage probability of secrecy capacity for assessing the secure communication.