Improved channel quantization for secret key establishment in wireless systems

This paper generalizes a channel quantization method for establishment of secret encryption keys by allowing the second node to shift quantization boundaries based on auxiliary information supplied by the first. Simulations reveal that this enhancement can provide significant improvement in key agreement probability while maintaining key establishment efficiency. While the technique has been demonstrated for the specific case where complex channel coefficients are quantized, it is easily applicable when quantizing other appropriate channel quantities, such as channel phase, wideband channel impulse response, or multipath component gains.