Method and Apparatus for Generating a Secret Key

摘要

A first partner connected to a channel collects samples of a physical variable on the basis of a time-variable property of the channel; stores a first array of at least bivalent elements; stores 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 a first state if the sample, to which the remaining element in the first array corresponds, is outside a limit range and representing a second state if the sample is within the limit range; receives a parity check bit from the second partner; subjects elements in the first array to a parity check using the parity check bit; and, if the parity check fails, determines a checked element in the first array whose corresponding element in the second array represents the second state, and inverts the determined element in the first array.

主权项

1. A method for generating a secret key, the method comprising:
collecting, 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, 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 if the sample is closer to a lower limit value than an upper limit value and representing a second state if the sample is closer to the upper limit value than the lower limit value; storing, 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 if 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 if the sample is within the limit range; receiving, with the first communication partner, a parity check bit from a second communication partner connected to the communication channel; subjecting, with the first communication partner, predetermined elements in the first array to a parity check using the parity check bit; and if the parity check fails:
determining, with the first communication partner, a checked element in the first array whose corresponding element in the second array represents the second state; andinverting, with the first communication partner, the checked element in the first array.