COKE Crypto-Less Over-the-Air Key Establishment

In this paper, we present a novel probabilistic protocol (COKE) to allow two wireless communicating parties to commit over-the-air (OTA) on a shared secret, even in the presence of a globally eavesdropping adversary. The proposed solution leverages no crypto but just plaintext messages exchange. Indeed, the security of the solution relies on the difficulty for the adversary to correctly identify, for each one-bit transmission, the sender of that bit-not its value, which is indeed exchanged in cleartext. Due to the low requirements of COKE (essentially, the capability to send a few wireless messages), it is particularly suited for resource constrained wireless devices (e.g., WNSs, wireless embedded systems), as well as for those scenarios where just energy saving is at premium, such as smartphones.