This paper discusses the security challenges, recent advances, and future trends in wireless communications. Wireless networks are inherently more vulnerable to security threats than wired networks due to their broadcast nature, which allows unauthorized users to access the network. This makes wireless communications more susceptible to attacks such as eavesdropping and jamming. The paper examines the security requirements of wireless networks, including authenticity, confidentiality, integrity, and availability. It also provides a comprehensive overview of security attacks encountered in wireless networks, discussing potential threats at each protocol layer. The paper surveys existing security protocols and algorithms used in wireless network standards such as Bluetooth, Wi-Fi, WiMAX, and LTE. It also discusses physical-layer security, an emerging technique for securing wireless communications against eavesdropping attacks. Several physical-layer security techniques are reviewed and compared, including information-theoretic security, artificial noise aided security, security-oriented beamforming, diversity assisted security, and physical-layer key generation approaches. The paper also introduces various jamming attacks and their countermeasures, including constant, intermittent, reactive, adaptive, and intelligent jammers. Additionally, it discusses the integration of physical-layer security into existing authentication and cryptography mechanisms for further securing wireless networks. Finally, the paper summarizes some unresolved technical challenges and discusses future trends in wireless security. The paper also provides a detailed overview of the security protocols used in wireless standards such as Bluetooth, Wi-Fi, WiMAX, and LTE, including their authentication, authorization, and encryption processes.This paper discusses the security challenges, recent advances, and future trends in wireless communications. Wireless networks are inherently more vulnerable to security threats than wired networks due to their broadcast nature, which allows unauthorized users to access the network. This makes wireless communications more susceptible to attacks such as eavesdropping and jamming. The paper examines the security requirements of wireless networks, including authenticity, confidentiality, integrity, and availability. It also provides a comprehensive overview of security attacks encountered in wireless networks, discussing potential threats at each protocol layer. The paper surveys existing security protocols and algorithms used in wireless network standards such as Bluetooth, Wi-Fi, WiMAX, and LTE. It also discusses physical-layer security, an emerging technique for securing wireless communications against eavesdropping attacks. Several physical-layer security techniques are reviewed and compared, including information-theoretic security, artificial noise aided security, security-oriented beamforming, diversity assisted security, and physical-layer key generation approaches. The paper also introduces various jamming attacks and their countermeasures, including constant, intermittent, reactive, adaptive, and intelligent jammers. Additionally, it discusses the integration of physical-layer security into existing authentication and cryptography mechanisms for further securing wireless networks. Finally, the paper summarizes some unresolved technical challenges and discusses future trends in wireless security. The paper also provides a detailed overview of the security protocols used in wireless standards such as Bluetooth, Wi-Fi, WiMAX, and LTE, including their authentication, authorization, and encryption processes.