Wireless-Assisted Key Establishment Leveraging Channel Manipulation

Abstract

Wireless communication is easily eavesdropped due to the broadcast nature of the wireless medium. This has spurred extensive research into secret key establishment using physical layer characteristics of wireless channels. In all these schemes, the secret keys directly originate from the physical features of the real wireless channel, which is highly dependent on the communication environment nearby. Also, previous schemes require performing information reconciliation, which increases both the costs and the risk of key leakage. In this paper, we exhibit a novel wireless key establishment method allowing the transmitter to specify arbitrary content as the key and cause the receiver to obtain the same key leveraging a channel manipulation technique. We furthermore enable the transmitter to apply error-correction code to the key, so that the receiver can automatically correct any mismatched bits without sending key-related information back to the transmitter over the public channel. Experimental results demonstrate that our key establishment method reaches a success rate as high as 91.0 percent for establishing a 168-bit key between the transmitter and the receiver, and meanwhile the chance that the eavesdropper can infer the key in meter-order range of the receiver is subdued into the range of 0~0.10 percent.