Providing privacy without encryption in multichannel systems

We introduce a new randomized distributed protocol designed to detect unauthorized reads in multichannel-communication systems, such as wavelength division multiplexed optical networks. We describe a method for modifying any available scheduling protocol for channel sharing, so that the new protocol does not use cryptography, yet it prevents eavesdropping by third parties. Our approach uses the tunability delay of optical transmitters and receivers as well as a special challenge-response scheme to guarantee privacy of communication. We provide two solutions to deal with different levels of attacks: (1) eavesdroppers working alone, and (2) eavesdroppers working in collaboration