Practical generation of secret bits using wireless channel measurements between two terminals is presented in this paper. The model used for this implementation assumes imperfect reciprocity between the channel measurements made by the two terminals in the presence of a passive eavesdropper. The channel measurements (e.g., received signal strength values) are used to estimate the secret key rate in order to establish the number of secret bits that can be generated between any two terminals. The main contributions of this paper are: 1) algorithm to generate uncorrelated channel measurements even when channel measurement statistics between the two terminals are time-varying; 2) development of a reconciliation algorithm based on BCH codes, where the statistics of error between bits generated by the two terminals is not known a priori; and 3) implementation of secret bit generation using channel reciprocity in a Linux environment. The channel measurement data that was collected for this paper is available at http://downloads.i-a-i.com/RAPOR.
['Satya Prakash Ponnaluri', 'Babak Azimi-Sadjadi', 'Yik-Kiong Hue', 'Tugba Erpek', 'Arash Komaee', 'Wade Trappe']
A practical wireless reciprocity-aware key establishment protocol