Secure detection in wireless sensor networks using a simple encryption method

The problem of binary hypothesis testing in a wireless sensor network is considered where observation of the sensors are quantized using identical binary quantizers and encrypted before transmission using a simple probabilistic cipher. The authorized or ally fusion center (AFC) is aware of the encryption process and the encryption parameters, whereas the unauthorized or third party fusion centers (TPFC) are unaware of the encryption parameters. The optimal threshold is evaluated for fixed values of the encryption parameters and numerical results are presented on the error probabilities of the two fusion centers. It is shown that by appropriate selection of the encryption parameters it is possible to degrade the performance of the TPFC significantly compared to that of AFC.