On The Secret Key Generation And Reconciliation For Wireless Network

With the rapid development of wireless communications,information-theoretic security for wireless communications has been pursued in recent years.Currently,the security of wireless networks mainly rely on the computational hardness of some open problems.This makes it very challenge with the development of modern computer,especially when its computation power is increased rapidly over time.As a branch of information-theoretic security,wireless physical layer security brings increased interests for wireless network.In essence,one can extract the key from wireless channel and reconcile the same key at two independent sides.In this paper,we focus on the secret key generation for wireless networks.The main contribution can be summarized as follows.(1)We provide further insights on the sensitivity of K-L transform,which can be well exploited to develop an improved version of K-L transform for removing the sensitivity in generating secret keys.With the improved K-L transform,some extra information should be sent over public channels,the amount of which can be well controlled so that the information revealed to the potential eavesdropper is minimized.When the sensitivity is removed,the proposed scheme can generate more secret bits with a low bit disagreement ratio.(2)In the process of wireless secret key generation,we show how to evaluate the impact on the rate of key generation rate with both quantization and reconciliation.We propose a low bound on this rate and show how to design the quantization scheme to minimize its effect on the rate of key generation.The rate of key generation is also connected to the specific key reconciliation scheme.Therefore,we also give insights how the key reconciliation scheme has its impact on the rate of key generation.(3)Based on the theory of secret key agreement by public discussion from common information,we devise a proximity authentication system for smartphones.The proposed method can achieve close proximity authentication by using correlated finger movements on the two smartphones.It does not require any prior secret information shared between the two devices,and generates the same highentropy cryptographic key for both devices in a successful authentication.