Patent ID: 8515061

Claim:
A method for generating a digital secret for digital secret key exchange, comprising: exchanging transmissions between a first device and a second device over at least one channel; receiving a first signal at said first device from said second device while exchanging said transmissions and during execution of a random movement on said first device; determining a first impulse response of said first signal transmitted over said at least one channel; generating a vector based on said first impulse response, wherein said vector comprises a plurality of elements; decorrelating said plurality of elements of said vector using a specified decorrelation transformation function to obtain a decorrelated vector; normalizing said decorrelated vector; and quantizing said decorrelated vector using a plurality of Gray code sequences to generate a digital secret, wherein the decorrelation and quantization provides uncorrelated binary data that is substantially identical at both the first and second devices, the uncorrelated binary data being used to generate the digital secret, wherein said quantizing said decorrelated vector comprises: grouping said decorrelated vector into a plurality of bins; assigning a corresponding code sequence to each of said plurality of bins, said corresponding code sequence comprising a first part and a second part, wherein said second part is comprised of a first Gray code sequence and a second Gray code sequence; and for each element of said decorrelated vector, selecting one of said first Gray code sequence and said second Gray code sequence based on said first part.