Patent ID: 9699652
Date: 2017-07-04
CPC Classifications: H04L,H04W

Claim:
1. A method for generating a secret key, the method comprising: collecting, using a processor, with a first communication partner connected to a communication channel, a plurality of samples of a physical variable on the basis of a time-variable property of the communication channel; storing, using the processor, with the first communication partner, a first array of at least bivalent elements, each element in the first array corresponding to at least one sample and representing a first state when the sample is closer to a lower limit value than an upper limit value and representing a second state when the sample is closer to the upper limit value than the lower limit value; storing, using the processor, with the first communication partner, a second array of at least bivalent elements, each element in the second array corresponding to a remaining element in the first array and representing the first state when the sample, to which the remaining element in the first array corresponds, is outside a limit range defined by the lower limit value and the upper limit value and representing the second state when the sample is within the limit range; receiving, using the processor, with the first communication partner, a parity check bit from a second communication partner connected to the communication channel; subjecting, using the processor, with the first communication partner, predetermined elements in the first array to a parity check using the parity check bit; when the parity check fails: receiving, with the first communication partner, a selection message from the second communication partner, and rejecting, with the first communication partner, selected elements in the first array on the basis of the selection message.