Patent ID: 7664955

Claim:
A method for establishing shared information, the method comprising: estimating characteristics of a communication channel between two nodes based on signals transmitted between the nodes; generating a first data sequence at the first node, the first data sequence being independent of any information shared with the second node; generating a second data sequence at the second node, the second data sequence being independent of any information shared with the first node; transmitting a signal from the first node to the second node, at least a portion of the signal being modulated with the first data sequence according to a first estimated characteristic; transmitting a signal from the second node to the first node, at least a portion of the signal being modulated with the second data sequence according to a second estimated characteristic; and forming shared information at each of the first and second nodes based on at least a portion of the first data sequence and at least a portion of the second data sequence, wherein forming the shared information at each of the first and second nodes comprises, at each node: combining the portion of the first data sequence and the portion of the second data sequence to form a combined sequence; and performing a predetermined function on the combined sequence to form the shared information.