Physical-layer entity authentication scheme for mobile MIMO systems

Exploiting physical layer in achieving different security aspects in wireless communications has been widely encouraged. In this work, the authors propose an entity authentication scheme for mobile devices with multiple antennas, which is purely based on physical layer parameters. According to the proposed scheme, in order to authenticate a device, a number of predefined authentication signals should be detected at the receive antennas on the authenticator side. The transmitted signals are designed based on the instantaneous channel responses in order to deliver the authentication signals to the receiver. The proposed scheme works efficiently even for mobile users, which is considered a significant improvement over previous related works. Mathematical analysis of the different involved factors along with sufficient simulations show the high performance of the proposed authentication scheme

A cryptographic perspective to achieve practical physical layer security

Communications, wired and wireless, have integrated various cryptographic techniques to ensure privacy and counter surveillance. These techniques have been integrated in most of the network layers, except for the physical layer. This physical layer has, thus far, dealt with schemes such as source coding, channel coding, and (de)modulation, to enable the transmission of data in a reliable and efficient manner. The emergence of physical layer security extends the functionalities at the physical layer to include secure communication, aiming at the transmission of a signal that can only be correctly retrieved by the intended receiver. Therefore, the goals of physical layer security align with cryptographic schemes utilized at the other network layers. From the extensive study of physical layer security schemes, we have observed that there is a knowledge gap regarding certain security principles practiced by cryptographers and the experts within physical layer security, causing many physical layer security schemes to be impractical for standardization and the wide-scale integration into information and communication technologies. This paper describes a variety of security principles and concepts, practiced by cryptographers, and of importance to physical layer security experts. We aim to raise the awareness of these security principles and concepts to experts within the field of physical layer security to improve the practicality, standardization, and integration potential of the design of future physical layer security schemes

An Efficient Cross-Layer Authentication Scheme for Secure Communication in Vehicular Ad-hoc Networks

Intelligent transportation systems contribute to improved traffic safety by facilitating real-time communication between vehicles and infrastructures. In this context, message authentication is crucial to safeguard vehicular ad-hoc networks (VANETs) from malicious attacks. The current state-of-the-art for authentication in VANETs relies on conventional cryptographic primitives, introducing significant computation and communication overheads. This paper presents a cross-layer authentication scheme for vehicular communication, incorporating the short-term reciprocal features of the wireless channel for re-authenticating the corresponding terminal, reducing the overall complexity and computation and communication overheads. The proposed scheme comprises four steps: S1. Upper-layer authentication is used to determine the legitimacy of the corresponding terminal at the first time slot; S2. Upon the verification result, a location-dependent shared key with a minimum number of mismatched bits is extracted between both terminals; S3. Using the extracted key and under binary hypothesis testing, a PHY challenge-response algorithm for multicarrier communication is proposed for re-authentication; S4. In the case of false detection, the key extraction step (S2) is re-executed after adapting the quantisation levels at different conditions of channel non-reciprocity based on the feedback from the re-authentication step (S3). Simulation results show the effectiveness of the proposed scheme even at small signal-to-noise ratios. In addition, the immunity of the proposed scheme is proved against active and passive attacks, including signatures' unforgeability against adaptive chosen message attacks in the random oracle model. Finally, a comprehensive comparison in terms of computation and communication overheads demonstrates the superiority of the proposed scheme over its best rivals