Publicly verifiable database scheme with efficient keyword search

The primitive of verifiable database (VDB) enables a resource-limited client to securely outsource a large and dynamic database on an untrusted server. Meanwhile, any misbehavior that attempts to tamper with the database can be detected undoubtedly. However, it seems that all existing VDB constructions only satisfy the basic query and update operations for a certain index performed by the client. In this paper, we first attempt to address the challenge of keyword-based search on VDB scheme. Specifically, we propose a concrete VDB construction supporting efficient keyword search based on the enhanced vector commitment, where each position of vector commitment is tied to a distinct keyword. Furthermore, we show how to extend the basic construction to support conjunctive keyword search. Security and efficiency analysis demonstrate that the proposed VDB schemes can achieve the desired security goals with high efficiency.