COKE Crypto-Less Over-the-Air Key Establishment

ESC: An efficient, scalable, and crypto-less solution to secure wireless networks

“…ESC is inspired by COKE [1]: ESC leverages channel anonymity to build up a peer-to-peer key establishment protocol and provides security at a network level, even in presence of multiple adversaries. In particular, we derive a theoretical lower bound for the security provided by our solution and support our findings with extensive simulation results.…”

“…Another solution comes from asymmetric cryptographic primitives, such as [16], nevertheless, asymmetric crypto is computationally expensive, and therefore, not suitable for massive devices deployment such as wireless sensor networks or devices that, once deployed, will be substantially unattendedoperating life being at premium. On-line key establishment without leveraging asymmetric crypto is a challenging issue that can be solved in mainly two ways: RSS based key establishment [7] or by means of anonymous channels [1,11,12]. The former solves the key establishment issue by transforming the observation of the RSS values in a shared secret: it has been proved that the received signal power estimated at both the peers of a communication link can be "transformed" on a shared secret between the two peers.…”

“…However, these solutions are exposed to recently introduced attacks [17]. Other solutions leverage anonymous channels [1]: the sender is anonymous, and the secret key is established as a function of the sender identity (ID) by a sequence of anonymous transmissions. The adversary easily eavesdrops the transmitted bits but cannot (deterministically) infer on the source identity, and therefore the key is (probabilistically) secure.…”

“…Asymmetric crypto techniques allow to establish secret keys without relying on pre-deployment procedures: after the deployment, nodes cooperate in order to share pairwise secrets among their neighbors. Asymmetric cryptographic schemes, such as [8], turn out to be particularly expensive from the energy perspective due to their high computational overhead [1,9]. Cyber-physical solutions provide real-time key establishment leveraging physical phenomena such as the received signal strength and the multipath fading.…”

“…The main idea relies on establishing a secret key between two peers without using crypto functions but leveraging source indistinguishability of an anonymous channel [9]. Recently, authors in [1] presented COKE: a crypto-less over-the-air key establishment protocol. COKE allows just two wireless communicating parties to commit on a shared secret, even in the presence of a globally eavesdropping adversary.…”