Signal Strength Seeded Frequency Hopping

Abstract

One approach to securing radio signals in wireless sensor networks is frequency hopping in which transmitters and receivers change frequencies at a predetermined interval using a pattern of frequencies that is programmed a priori or calculated dynamically via ashared seeding mechanism. For these systems, if an adversary can physically capture a node in the network and steal the seed or hopping set, it can compromise the network. To protect against this weakness, we propose Signal Strength Seed Frequency Hopping, a hopping set selection scheme in which the seed used to calculate a dynamic hopping set is generated using signal strength measurements collected after the network has been deployed. We show our scheme has sufficient stochasticity to produce hopping sets that cannot be easily reproduced by an adversary.