Manipulatable wireless key establishment

摘要

Due to the broadcast nature of the wireless medium, private communications are easily eavesdropped. This has spurred extensive research into secret key establishment using physical layer characteristics of wireless channels. In all these schemes, the shared 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 of key establishment and the risk of key leakage over the not yet secured channel. In this paper, we exhibit a novel wireless key establishment method allowing the transmitter to specify arbitrary content as the secret key and cause the receiver to obtain the same key by using a channel manipulation technique. At the same time, eavesdroppers are prevented from deriving the secret key. We furthermore exploit the transmitter's ability to specify any content as the key by enabling the transmitter to apply error-correction code to the key. This means the receiver can automatically detect and correct any mismatched bits without sending key-related information back to the transmitter over the public channel. Experimental results demonstrate that the our key establishment method reaches a success rate as high as 91.0% 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%.