A new efficient algorithm for executing queries over encrypted data

Outsourcing databases into cloud increases the need of data security. The user of cloud must be sure that his data will be safe and will not be stolen or reused even if the datacenters were attacked. The service provider is not trustworthy so the data must be invisible to him. Executing queries over encrypted data preserves a certain degree of confidentiality. In this paper, we propose an efficient algorithm to run computations on data encrypted for different principals. The proposed algorithm allows users to run queries over encrypted columns directly without decrypting all records.