Cooperative Group Secret Key Generation Based on Secure Network Coding

Most of the existing works on group secret key (GSK) generation are based on pairwise key which wasting the total time and power of the group users. We present a cooperative GSK generation algorithm via star topology with one central node and one reference node. After channel estimation, secure network coding technique is employed by the central node to help all the group users exploit the randomness of reference channel with nothing about that leaking to the eavesdropper. Then all the group users agree on a secret key from the correlative observations of the reference channel in one information reconciliation phase. In addition, the expression of achievable secret key rate is derived. Theoretical and Monte Carlo simulation results validate the performance of our proposed algorithm.