A Remark on the AAA Method for Secret-Key Generation in Mobile Networks

A broadly applicable method for secret-key generation is named for its accumulative, adaptable and additive (AAA) properties. This paper first shows a robustness of its performance. Namely, even if there is an inter correlation or a leakage caused intra correlation among the superimposed packets, provided there is a nonzero probability for each packet to be missed in full or in part by Eve, then the equivocation of the key generated by the AAA method always becomes perfect as the number of superpositions becomes infinite. Also shown in this paper is a comparison between the AAA method and an ideal method based on reciprocal channel estimation, which reveals several advantages of the AAA method.