Enabling verifiable multiple keywords search over encrypted cloud data

Abstract

Searchable Encryption (SE) enables a user to search over encrypted data, such as data stored in a remote cloud server. Existing certificate-, identity-, and attribute-based SE schemes suffer from certificate management or key escrow limitations. Furthermore, the semi-honest-but-curious cloud may conduct partial search operations and return a fraction of the search results (i.e., incomplete results) in order to reduce costs. In this paper, we present a secure cryptographic primitive, Verifiable Multiple Keywords Search (VMKS) over ciphertexts, which leverages the Identity-Based Encryption (IBE) and certificateless signature techniques. The VMKS scheme allows the user to verify the correctness of search results and avoids both certificate management or key escrow limitations. We then demonstrate the security of proposed VMKS scheme (i.e., the scheme achieves both ciphertext indistinguishability and signature unforgeability). We also use a real-world dataset to evaluate its feasibility and efficiency.