Enhancements to ODXT SSE Scheme: Algorithm Optimization and Leakage Suppression

A Dynamic SSE (Searchable symmetric encryption) scheme should support updates and keyword searches with outsourced symmetrically encrypted data while minimizing the amount of data revealed to the untrusted server. For this purpose, literature in this field has identified two critical security properties, i.e. forward and backward privacy.In this work, we build upon the previously developed "Oblivious Dynamic Cross Tags" (ODXT) scheme for conjunctive keyword searches, featuring forward and backward privacy. The objective is to improve flexibility in the update operation of the given scheme, solve the open problem of s-term leakage, and perform leakage analysis of the improved scheme. We propose flexODXT, to reduce the time required for individual keyword update operations to a constant instead of linear complexity, and we propose suppODXT, to reduce the s-term leakage, an open problem found in ODXT.