Forward-Secure Key Evolution in Wireless Sensor Networks

The authors consider a key distribution scheme for securing node-to-node communication in sensor networks. While most schemes in use are based on random predistribution, the authors consider a system of dynamic pairwise keys based on design due to Ren, Tanmoy and Zhou. The authors design and analyze a variation of this scheme, in which capturing a node does not lead to security threats for the past communication. Instead of bit-flipping, this paper uses a cryptographic one-way function. While this immediately guarantees forward-security, it is not clear whether the pseudorandom transformation of the keys does not lead to subtle security risks due to a specific distribution of reachable keys, such as existence of small attractor subspaces.