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On efficient key pre-distribution in large scale wireless sensor networks

In a wireless sensor network, pre-distribution of secret keys is possibly the most practical approach to protect network communications. To meet the stringent resource constraints of the sensor nodes, such as limited storage capability, low computation capability, and limited battery life, key pre-distribution schemes should be highly efficient, namely requiring as little storage space as possible, and at the same time, maintain a strong security strength, i.e., high resilience against node capture. In this paper, a new approach for random key pre-distribution is proposed to achieve both efficiency and security goals. The novelty of this approach lies in that, instead of using a key pool consisting of random keys, a random key generation technique is carefully designed such that a large number of random keys can be represented by a small number of key-generation keys. Then, instead of storing a big number of random keys, each sensor node stores a small number of key-generation keys while computes the shared secret key during the bootstrapping phase on-the-fly using efficient hash operations. The proposed scheme outperforms the previous random key pre-distribution schemes by significantly reducing the storage requirement while holding the same security strength as shown by the detailed analysis