Abstract
We studied secure homomorphic as well as searchable encryption in this work. In ad hoc/sensor networks, quite often we need to gather data from those sensors to a fixed sink and process them, such as a group of sensor nodes responsible for gathering temperature data gathering. In order to ensure user's privacy, all gathered data must be encrypted to be sent to the sink. Each piece of data are to be summed up at the sink via homomorphic encryption. In this paper, we consider the scenario where a group of users share some encrypted group data stored at the sink. Each authorized user must be able to efficiently retrieve the group data so he/she can contribute his/her own piece to be merged with the group data via homomorphic encryption. Our proposed scheme is both provably secure and practical in both ad hoc/sensor networks as well as cloud computing. © 2013 IEEE.