A cluster based multi-keyword search on outsourced encrypted cloud data

Cloud provides an illusion of infinite storage to the user at limited setup and usage cost. Due to the availability of resources at low initial investment cost and fast internet speed, the organizations are motivated to outsource their data on cloud. But storing secure and confidential data on cloud introduces many security risks, namely data leakage, data theft and reduced control on data. In order to maintain confidentiality, the data is encrypted before outsourcing it to cloud. But this introduces the problem of efficient searching on the cloud. Several approaches exist for searching on this encrypted data stored on cloud but require large number of comparisons and time to search the desired documents. In this paper, we propose a cluster based privacy preserving multi-keyword search scheme over encrypted cloud data. The proposed search scheme retains the security requirements as proposed in the existing approaches in literature but provides results efficiently. Experimental results demonstrate the effectiveness of the proposed search scheme as it reduces the number of comparisons required to search the desired document by 80% for dataset with 6000 documents. Also, the time required to search the desired documents is also reduced by 70% for the same dataset as compared to the existing efficient search schemes in literature.