Abstract
Recently, concealed data aggregation schemes have been proposed to reduce the transmission cost under maintaining data privacy. Those schemes enhanced security of conventional aggregation through utilizing privacy homomorphic encryption. The privacy homomorphic encryption provides algebraic computations on ciphertexts directly, e.g., without decryption ciphertexts.Unfortunately, it does not support extreme value selections, such as median, minimum, or maximum. Hence, we construct a novel sorting scheme on ciphertexts without decryption where ciphertexts are generated by Elliptic Curve ElGamal encryption. Moreover, the proposed scheme could be preserve additive homomorphic property of the Elliptic Curve ElGamal encryption. Deployed aggregator can execute sorting according to different cases. To the end of this paper, the proposed scheme has been evaluated on physical sensor system. Comprehensive analyses and comparisons are shown to prove that the proposed scheme is practical and efficient. ©2010 IEEE.