Physical layer multi-user key generation in wireless networks

Ehsan Olyaei Torshizi, Anas Alashqar, Werner Henkel

Ehsan Olyaei Torshizi, Anas Alashqar, Werner Henkel

Chen K. Sun, Guyue Li, Hongyi Luo +1 more

This chapter presents a multi-user secret key generation in massive multiple-input multiple-output (MIMO) wireless networks. Physical-layer key generation (PKG) based on channel reciprocity has emerged as a new technique to establish secret keys between devices. However, in future wireless communications, massive antennas will be employed to support multiple users, which bring new challenges to PKG, e.g., low key agreements caused by long-time delay or strong inter-user interference. By harnessing the sparse characteristics of the beam domain channel model, we propose a general channel dimensionality reduction (CDR)-based secret key generation scheme and optimize the parameters of this scheme. The security of this key generation scheme under different user cases of non-overlapping and overlapping beams is then discussed. Some new directions that generalize and improve the basic scenarios for PKG are described. These new directions include multi-cell multi-user secret key generation, PKG in millimeter wave wireless communications, and PKG in frequency division duplexing systems.

Ufuk Altun, Semiha Tedik Başaran, Güneş Karabulut Kurt +1 more

In this paper, we consider the problem of secret key generation for multiple parties. Multi-user networks usually require a trusted party to efficiently distribute keys to the legitimate users and this process is a weakness against eavesdroppers. With the help of the physical layer security techniques, users can securely decide on a secret key without a trusted party by exploiting the unique properties of the channel. In this context, we develop a physical layer group key generation scheme that is also based on the ideas of the analog function computation studies. We firstly consider the key generation as a function to be computed over the wireless channel and propose two novel methods depending on the users transmission capability (i.e. half-duplex and full-duplex transmissions). Secondly, we exploit the uniqueness of the prime integers in order to enable the simultaneous transmission of the users for key generation. As a result, our approach contributes to the scalability of the existing physical layer key generation algorithms since all users transmit simultaneously rather than using pairwise communications. We prove that our half-duplex network model reduces the required number of communications for group key generation down to a linear scale. Furthermore, the full-duplex network model reduces to a constant scale.

Hasan Taha

Shunyi Hu

Abstract This paper proposes a Physical Layer Network Coding (PLNC) scheme based on two channels pre-balanced by studying the PLNC technology and the security problem of the Network Coding (NC) system to solve the security problem of PLNC in Wireless Communication (WC). This security scheme focuses not only on the key generation process but also on the use of generated keys for encryption and decryption during the transmission of useful information by the NC system. In addition, for the security risks of the traditional Private Random Precoding (PRP) Key Exchange Algorithm (KEA), this paper proposes an improved PRP. The security and confidentiality of the KEA are strengthened. The method is applied to multi-user scenarios to verify. The results show that the security scheme based on channel time domain key generation encryption can ensure the security of the PLNC system and effectively prevent the eavesdropping attacks of illegal users. Compared with other algorithms, the improved PRP KEA significantly reduces the key error rate of generating a 64-bit key under the same conditions compared to the key when generating a 16-bit key, reaching less than 10-3. In scenarios with high correlation coefficients, the improved algorithm leaks less information than other algorithms and has higher security performance. Therefore, the improved KEA performs well for the physical layer network security problem in WC.