A novel method for designing indexes to support efficient substring queries on encrypted databases.

Recently, the queries techniques on encrypted character data in database have been interested which concentrate to searching keywords. In this paper, we propose Double Indexes Query - Searchable Symmetric Encryption (DIQ-SSE) schema which is performed in Proxy model. This schema allows effectively querying any substring on encrypted character field on outsource databases. The idea of this schema is that each plaintext A s at the safety zone of Proxy is encrypted with traditional encryption algorithms. In this time, two special index sets of Index1 and Index2 are built for supporting search. The tuple of (cipher, Index1, and Index2) that corresponding A s are stored on outsource database. To perform the queries, 4 phases are used. Firstly, the query command is transformed. Secondly, the query is performed on Index1. Then, the task is continued of querying on Index2 for data taken from phase 2. In the last phase, data is decrypted, and query on plaintext is performed. Beside of proposing algorithm of building indexes and queries on 4 phases, the paper also focuses on the protection analysis as well as experimental evaluations. [ABSTRACT FROM AUTHOR]