Fully homomorphic encryption: Searching over encrypted cloud data

Searching over encrypted data is a very important property that can offer some encryption schemes. It means performing queries on encrypted data in the absence of purpose to decryption, which permits to preserve confidentiality of sensitive data. Private Information Retrieval (PIR) is an essential protocol when selected information from remote databases is wanted to be done in secrecy. Fully homomorphic encryption is a revolutionary domain of cryptography that allows processing encrypted data without the need of any prior decryption, thus generating an encrypted result that corresponds the result of operations performed on the plaintext. In this paper we will exploit the important property that can offer the powerful fully homomorphic encryption to show how to realize a PIR protocol and how to search over encrypted data in a cloud context. © 2017 Association for Computing Machinery.