A major limitation of physical layer security is the requirement for prior knowledge of the potential eavesdroppers' (Eves) channels, which makes its practical implementation challenging. Integrated sensing and communication systems can be exploited to address this issue by enabling both communication and sensing functionalities, sensing the physical environment to estimate Eves' directions and amplitudes, and further reconstructing their channel state information (CSI) to achieve sensing-assisted wiretap channel awareness, thus realizing secure communication. We analyze a more practical scenario where not only is reconstructed Eves' CSI inaccurate, but also the CSI of the legitimate user equipments (UEs) estimated by the base station is imperfect, and Eves are equipped with multiple antennas. To resolve this, we propose a robust optimization problem that jointly maximizes the sensing accuracy and the secrecy rate by co-designing the beamforming and the artificial noise matrix. For the highly challenging non-convex infinite objective function, the S-Procedure is introduced, which is then solved by an efficient algorithm based on alternating optimization and successive convex approximation. Numerical results validate the effectiveness of the proposed algorithm and demonstrate that the robust beamforming scheme can mitigate the impact of channel uncertainty (both UEs' and Eves') on the system performance.

The interoperability of satellite networks is crucial for achieving global low latency connections in B5G/6G communication. However, the use of different crypto-systems by multiple operators poses security threats such as cross domain identity spoofing and man-in-the-middle attacks. This article proposes a two-way anonymous and cross PKI-IBC authentication mechanism for the inter-satellite-networks interoperability scenarios. The proposed mechanism pre-establishes trust between authority centers of diverse operators. When authenticating, satellites online request the public key of the opponent’s operator’s authority center. Thus, satellites can guarantee the authenticity of each other’s public keys and then verify their identities mutually. We also generate temporary symmetric keys to conceal the public key and identity of the satellites, preserving identity privacy. Finally, the session key is derived through symmetric encryption to ensure the confidentiality of subsequent messages. ProVerif and BAN logic have formally verified that the proposed mechanism can achieve mutual authentication and key negotiation, while ensuring that private keys are not leaked. The numerical results indicate that our mechanism has lower authentication latency and communication overhead compared to existing schemes.

The mobile communication network is gradually shifting from the deployment of dedicated physical facilities to the deployment of virtualized network functions on general infrastructure. Taking advantage of this transformation, operators can provide customized services to better meet the demands of vertical industries. However, the participation of vertical industry tenants introduces a new attack surface to the mobile networks. The centralized access control scheme currently employed in the 5G system has a high risk of single-point failure and privacy leakage. And it is inefficient when the scheme is applied in distributed core networks. To secure the mobile communication network and protect the privacy of vertical industry tenants, we propose a distributed policy-hidden (DPH) framework, which achieves flexible cross-trust-domain authorization with lower latency. Besides, Attribute-based Encryption is introduced to protect long-distance communications between network functions. Our evaluation demonstrates that DPH is suitable for virtualized 5G networks and effectively reduces the latency of authorization procedures.

Integrated Sensing and Communication (ISAC) can reuse the same spectrum and hardware resources for communication and radar sensing, which is a promising technology to alleviate spectrum congestion. Recently, there has been an increasing research interest in the physical layer secrecy aspects of ISAC systems. This paper studies a basic multiple-input single-output ISAC secrecy system, where a multi-antenna base station transmits a unified signal to sense a point target and communicate to a single-antenna receiver in the presence of$K$single antenna eavesdroppers. Under this setup, a sensing signal-to-noise ratio (SNR) constrained secrecy rate maximization problem has been formulated. We showed that the problem can be reformulated as a convex semidefinite programming problem and proved that beamforming is the optimal transmission scheme. We derived two low-complexity semiclosed-form optimal beamforming solutions and one suboptimal closed-form solution. Numerical results demonstrate that the proposed solutions attain the optimum of the sensing SNR constrained secrecy rate maximization problem and have lower computational complexity than the existing method.

The handover process in an integrated terrestrial-satellite network (ITSN) faces many security threats, such as eavesdropping, impersonating, replaying, and privacy leakage due to the link exposure and network heterogeneity of ITSN. This paper proposes a lightweight and privacy-preserving ITSN handover authentication mechanism based on elliptic curve cryptography to eliminate the security threats. Specifically, we propose to directly authenticate mobile users at access nodes and on a batch basis, hence avoiding backhaul and concurrent authentication overhead. User anonymous identity and private information encryption are adopted to protect users’ privacy. A regular key update scheme is developed to mitigate a risk of private key breach. As demonstrated by a formal security proof based on the AVISPA tool and security analysis, the proposed mechanism resists various attacks (e.g., replay attacks and impersonation attacks). Numerical results show that our mechanism is more efficient than the standard and the existing alternatives. The proposed mechanism has the great potential to secure the handover processes of emerging ITSN.