Keep your Enemies closer: On the minimal Distance of Adversaries when using Channel-based Key Extraction in SISO 6G Systems

We conduct a comprehensive analysis of Channel-based Key Extraction across various frequency ranges that have potential applications in the 6th generation mobile standard. Specifically, we examine the minimum distance required between an attacker and a legitimate entity to achieve secure key generation through channel measurement. By simulating various metrics across diverse configurations, we observe that in our generic model, the required distance for an attacker to attain sufficient channel correlation reduces as frequency increases. Consequently, an attacker must be within close proximity, mere centimeters away, from a legitimate node to acquire relevant information necessary for generating a potentially identical key.