Secret Key Agreement for Cooperative Wireless Communications: Bounds and Efficient Protocol Design
The authors study practical information-theoretically secure secret key agreement protocol design for wireless cooperative communication networks. By assuming the relay selection process is finished in advance, they study the key agreement problem for a classical three-node cooperative wireless communication system over independent Additive White Gaussian Noise (AWGN) channels. Passive attacks from an eavesdropper collocated with the relay are assumed. They derive upper and lower bounds on the secret key rate under the assumed cooperative wireless system model and find that they are close, which indicates the tightness of the bounds. They then propose an efficient practical secret key agreement protocol with both Bob and the honest relay participating in the public discussion.