Field-restricted search over outsourced and encrypted data

Searchable encryption (SE) technique enables the users to search for the encrypted documents by keywords. As an implicit assumption, the documents are always treated as unstructured texts. However, in the real world, there are many structured documents such as metadata, XML etc. To further utilize the internal structure to supply more advanced query, we propose a novel field-restricted searchable encryption scheme based on a new proposed anti-statistic bloom filter structure and bi-word indexing technique. The new scheme enables the users to specify the search field without leaking any information about the document structure, and experiments show that it is both efficient and privacy-preserving. In overall, the new scheme extends the application of the previous schemes and greatly improves the user experience.