| 摘要 |
<p>A key agreement method for secure communication in a multiple access system is provided. A key agreement method for secure communication in a multiple access system, the key agreement method includes the steps of (a) a first system, modulating signals from a source by a bit sequence and transmitting the modulated signal, (b) a second system, a legitimate counterpart of the first system, decoding , making decision for each bit of the signal with a detector affected by noise and recording the measured values, (c) the second system, deciding a threshold value of measurement with consideration of other factors such as a transmission rate, tolerable error rates, and a degree of security, (d) the second system adopting as a key string only bits having values beyond the threshold value and ignoring bits falling the erroneous region below the threshold, (e) the second system informing the first system that the n-th bit is adopted , not telling the value of the bit, and (f) the users, the first system and the second system, taking as a key string the values of the n-th bits adopted in (e) , and discarding the values of the other bits. <IMAGE></p> |
