Issue No. 01 - January (2010 vol. 9)
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/TMC.2009.88
Neal Patwari , University of Utah, Salt Lake City
Jessica Croft , University of Utah, Salt Lake City
Suman Jana , University of Utah, Salt Lake City
Sneha Kumar Kasera , University of Utah, Salt Lake City
Secret keys can be generated and shared between two wireless nodes by measuring and encoding radio channel characteristics without ever revealing the secret key to an eavesdropper at a third location. This paper addresses bit extraction, i.e., the extraction of secret key bits from noisy radio channel measurements at two nodes such that the two secret keys reliably agree. Problems include 1) nonsimultaneous directional measurements, 2) correlated bit streams, and 3) low bit rate of secret key generation. This paper introduces high-rate uncorrelated bit extraction (HRUBE), a framework for interpolating, transforming for decorrelation, and encoding channel measurements using a multibit adaptive quantization scheme which allows multiple bits per component. We present an analysis of the probability of bit disagreement in generated secret keys, and we use experimental data to demonstrate the HRUBE scheme and to quantify its experimental performance. As two examples, the implemented HRUBE system can achieve 22 bits per second at a bit disagreement rate of 2.2 percent, or 10 bits per second at a bit disagreement rate of 0.54 percent.
Wireless networks, multipath fading, physical layer, cryptography, key generation.
J. Croft, S. K. Kasera, S. Jana and N. Patwari, "High-Rate Uncorrelated Bit Extraction for Shared Secret Key Generation from Channel Measurements," in IEEE Transactions on Mobile Computing, vol. 9, no. , pp. 17-30, 2009.