Searchable encryption : A survey

We explore the field of searchable encryption (SE) and present a comprehensive survey of relevant literature. Since the existing survey articles are primarily written for the security experts, we present the discussion to assist the general practitioners (not from security background) in identifying an appropriate SE scheme for their application of interest. We initiate with the brief overview of SE along with its application-oriented criteria. By analyzing various SE schemes, we derive five significant characteristics – key structure, search structure, search functionality, support to reader/writers, and reader's capability. Based on these characteristics, we categorize the existing SE schemes and showcase the significant features offered by each scheme. We explore numerous schemes based on symmetric/asymmetric key structures, simple/inverted search structure, single/multi-keyword search functionality, single/multiple reader/writer support, and verification functionality owned by data reader. A most promising part of the survey is the comparative analysis of the existing schemes under specific category in terms of tables showing efficiency and security. We hope that this survey is indeed beneficial for the general practitioners to pick an appropriate SE scheme better suited to the selected application.