Verifiable Ranked Search over dynamic encrypted data in cloud computing

Big data has become a hot topic in many areas where the volume and growth rate of data require cloud-based platforms for processing and analysis. Due to open cloud environments with very limited user-side control, existing research suggests encrypting data before outsourcing and adopting Searchable Symmetric Encryption (SSE) to facilitate keyword-based searches on the ciphertexts. However, no prior SSE constructions can simultaneously achieve sublinear search time, efficient update and verification, and on-demand file retrieval, which are all essential to the development of big data. To address this, we propose a Verifiable Ranked Searchable Symmetric Encryption (VRSSE) scheme that allows a user to perform top-K searches on a dynamic file collection while efficiently verifying the correctness of the search results. VRSSE is constructed based on the ranked inverted index, which contains multiple inverted lists that link sets of file nodes relating a specific keyword. For verifiable ranked searches, file nodes are ordered according to their ranks for such a keyword, and information about a node's prior/following neighbor will be encoded with the RSA accumulator. Extensive experiments on real data sets demonstrate the efficiency and effectiveness of our proposed scheme.