Forward-secure Key Evolution Protocol
in Wireless Sensor Networks **
M.Klonowski, M.Kutylowski,
(Wroclaw University of Technology)
M.Ren, K.Rybarczyk
(Adam Mickiewicz University, Poznan)
We consider a key distribution scheme for
securing node-to-node communication in sensor networks.
While most schemes in use are based on random predistribution, we
consider a system of dynamic pairwise keys based on design due to Ren, Tanmoy and Zhou.
We 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, we use a pseudorandom one-way function.
While this immediately guarantees forward-security, it is not clear
whether the pseudorandom transformation of the keys does not lead to security problems
through a potentially reduced size of the keyspace or nonuniform probability
distribution of the keys. We show, in a rigid mathematical way, that this is not the case: after a relatively small number of transformations,
with high probability each key can be reached and no key has probability significantly
higher than for the uniform distribution.
*The 6th International Conference on Cryptology and Network Security (CANS) 2007
To appear in LNCS, Springer-Verlag