A Cloud Access Security Broker based approach for encrypted data search and sharing

Encryption will play a more important role as more computation and storage are outsourced. Achieving good balance between strong security and application functionality preservation becomes a cutting-edge research problem. SE algorithms are well studied, which delegate search capabilities to the cloud provider without decrypting the documents. But this approach imposes extra constraints on cloud API and loses search query expressiveness. This paper proposes a CASB based framework for encrypted search and data sharing, which builds the search index locally and only points the identifiers of ciphertext into cloud, promisingly expresses full set search functionalities while using keys that the user can control. Experimental results are taken to quantitatively analyze the performance overhead and throughput of the broker.