Authors:
Jan Lehnhardt
1
;
Tobias Rho
1
;
Adrian Spalka
1
and
Armin B. Cremers
2
Affiliations:
1
CGM AG and University of Bonn, Germany
;
2
University of Bonn, Germany
Keyword(s):
Databases, Indexes, Cryptography, Cloud-based Information Systems.
Related
Ontology
Subjects/Areas/Topics:
Information and Systems Security
;
Privacy Enhancing Technologies
Abstract:
For information systems in which the server must operate on encrypted data (which may be necessary
because the service provider cannot be trusted) solutions need to be found that enable fast searches on
that data. In this paper we present an approach for encrypted database indexes that enable fast inequality,
i.e., range searches, such that also prefix searches on lexicographically ordered but encrypted data are
possible. Unlike common techniques that address this issue as well, like hardware-based solutions or order-preserving
encryption schemes, our indexes do not require specialized, expensive hardware and use only
well-accredited software components; they also do not reveal any information about the encrypted data
besides their order. Moreover, when implementing the indexing approach in a commercial software product,
multiple application-centric optimization opportunities of the index’s performance did emerge, which are
also presented in this paper. They include basic pe
rformance-increasing measures, pipelined index scans and
updates and caching strategies. We further present performance test results proving that our indexing
approach shows good performance on substantial amounts of data.
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