Abstrait

Enabling Search and Retrieval over Encrypted Data Using Homomorphic Encryption

Jiss Varghese, Lisha Varghese , Fabeela Ali Rawther

Outsourcing of data has become an advanced data service to store information into a global storage space. Data owners can upload their private data onto these space, and do many operations on them. Performing information retrieval tasks while preserving data confidentiality is a big challenge when data is stored on a global space maintained by a third-party service provider. To avoid confidentiality problem, the sensitive data have to be encrypted before uploading onto servers. This leads to a problem to perform efficient keyword based search and retrieval over the encrypted data. Several searchable symmetric encryption schemes are available but they support only Boolean keyword based search. i.e., a file is retrieved based upon whether the queried keyword is present or not without considering the relevance. This paper proposes a novel scheme called homomorphic encryption which allows different computations to be applied on encrypted data. This property enables scoring and ranking computations which gives sufficient search accuracy and enables users to involve in ranking by doing computations only on ciphertext. Since search operation is performed over encrypted data, information leakage can be eliminated and data can be searched and retrieved efficiently.