Towards forward secure verifiable data streaming with support for keyword query

Verifiable data streaming (VDS) allows users to continuously upload their encrypted data items to untrusted cloud servers to reduce the burden of local storage. Meanwhile, it enables users to update outsourced data and initiate queries to verify data integrity. However, most previous works focus on queries for a certain index and are not compatible with general keyword queries. To this end, we propose a VDS protocol that supports keyword queries. Specifically, we first present an efficient dynamic symmetric searchable encryption (DSSE) with range query, which can represent multiple queried keywords within a range as the concise query token, thereby achieving communication-optimized keyword queries while achieving unbounded data appending. Furthermore, we construct a new VDS protocol supporting keyword queries by integrating the proposed range DSSE. Specifically, suppose the user searches for multiple keywords within a certain range. In that case, cloud servers can match the corresponding data items based on the user's query token, and users can verify the integrity of these data items. Security analysis demonstrates that our VDS protocol achieves forward security. Experimental results show that it sacrifices acceptable costs in exchange for keyword retrieval capability.