End-to-End Key Establishment with Physical Layer Key Generation and Specific Attacker Models

Physical layer key generation got much attention during the last time. However, the need of a common physical channel implies that only point-to-point keys can be generated. In this chapter, we investigate approaches how these point-to-point keys can be used for a secure establishment of end-to-end keys between two users who can only communicate over a multi-hop network. We start with a review of physical layer key generation taking different attacker models into account. Subsequently, we introduce general approaches for the end-to-end key establishment in the presence of various attackers who differ in their behavior and their area of control. We discuss four different path selection algorithms for the key establishment and evaluate their performance by means of simulations. The results show that the end-to-end key establishment can be protected by means of physical layer keys with a reasonable effort if suitable path selection is applied.