5G and beyond networks will require fast, energy efficient, and secure initial access. In this study, a deep learning-based secure initial beam selection method is proposed that ranks the beam pairs between a transmitter and a legitimate user aiming to maximize the signal strength the user receives, while keeping the signal strength that the eavesdropper sees below a threshold. Instead of an exhaustive search, the initial beam selection is performed over a limited number of the top beam pairs, leading to reduced communication overhead and energy consumption. The proposed scheme is evaluated using data obtained from a real-life mobile network topology as well as a synthetic data set based on the same geographical site but with statistical system-level environment variables. Numerical results show that the signalling overhead can be reduced by 75% with 99.66% accuracy in terms of the best beam pair, and 99.89% of the achievable signal strength. In terms of security, the proposed method has been shown to improve secure coverage probability by 68.12% compared to the best-coverage beam selection scenario.INDEX TERMS 5G, physical layer security, beam management, mMIMO, NR SSB beam sweeping, deep learning, DNN.Recently, machine learning (ML), especially deep learning (DL), has become a prominent technique in a wide range of research areas for mobile and wireless networks. Potential areas of DL include mobility analysis, user localization, wireless sensor networks, network control, network security, signal processing, network-level and application-level mobile data analysis [5]. Specifically, DL has been proposed to be used in the beam management processes. It excels at extracting nonlinear features in angular and time domains, ensuring highly accurate beam pair prediction. Additionally, it has been proposed for predictive beam switching to mini-