Vulnerabilities of physical layer secret key generation against environment reconstruction based attacks

This letter investigates the security of physical layer secret key generation in highly reconfigurable scattering environments. Based on our derived secret key capacity expression, we show that the eavesdropper's accurate knowledge of surrounding environments and propagation laws can significantly decrease the secret key capacity, i.e., the security of keys does not only rely on the channel correlation. We term this new physical layer attack as Environment Reconstruction based Attack for SEcret keys (ERASE) and provide a practical application of this attack based on a generalized 3D channel model. Finally, the impact of crucial parameters related to the channel scattering conditions is analyzed through simulation results, and useful insights for the secure and practical design of physical layer key generation are highlighted.