An enhanced wildcard-based fuzzy searching scheme in encrypted databases

Under the overwhelming trend in Cloud Computing, Cloud Databases possessing high scalability / high availability / high parallel performance have become a prevalent paradigm of data outsourcing. In consideration of security and privacy, both individuals and enterprises prefer to outsource service data in encrypted form. Unfortunately, most encrypted databases cannot support such complicated queries as wildcard-based fuzzy searching, which, to some extent, limits the practicability in real applications. To explore more business logic in encrypted databases, an enhanced wildcard-based fuzzy searching scheme (enWFS) is proposed in this paper, which integrates specialized Adjacent Character Matrix/Tensor into proxy middleware, appends two types of ancillary columns into data tables, as well as designs an advanced adaptive overwriting method to revise query expressions with wildcards (‘%’ and ‘_’). Meanwhile, some security enhancements and TupleRank are added to enWFS scheme so as to achieve superior fuzzy searching experiences. Extensive experiments based on real datasets demonstrate effectiveness, feasibility of our proposal.