High-Rate Uncorrelated Bit Extraction for Shared Secret Key Generation from Channel Measurements

—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) non-simultaneous 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 de-correlation, and encoding channel measurements using a multi-bit 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...

• Type: Journal
• Year: 2010
• Where: TMC
• Authors: Neal Patwari, Jessica Croft, Suman Jana, Sneha Kumar Kasera
• Keywords: Bit Disagreement, Bit Disagreement Rate, Secret Keys, TMC 2010