Multi-Client Dynamic Searchable Symmetric Encryption Scheme with Supporting Conjunction Query

The separation of data storage and usage in cloud environments usually causes some new convenience and security problems. Searchable encryption is constructed to solve these problems. Compared to searchable asymmetric encryption schemes, Searchable Symmetric Encryption (SSE) receives widespread attention due to its higher search efficiency. However, most of these schemes only support a single client for search operations, which is considered inconvenient in reality. By adding an authorized data set (ASet) and extending the oblivious dynamic cross tags (ODXT) scheme, which supports conjunction query, a new dynamic searchable symmetric encryption with supporting conjunction query and multi-client is constructed. Using the digital envelope and existing cloud storage servers to achieve authorization params transfer securely between data owner client and authorized searching client, without the need for new hardware and without keeping the data owner always "online", which gets better adaptability to reality. The implementation results indicate that the scheme can meet the application requirements of multi-client scenarios and has less storage and computational overhead.