Combining Fragmentation and Encryption to Protect Data Privacy

Abstract

Traditional solutions for granting data privacy rely on encryption. However, dealing with encrypted data makes query processing expensive. In this chapter, we propose a solution to enforce privacy over data collections combining data fragmentation with encryption.We model privacy requirements as confidentiality constraints expressing the sensitivity of the content of single attributes and of their associations. We then use encryption as an underlying (conveniently available) measure for making data unintelligible, while exploiting fragmentation to break sensitive associations among attributes. We introduce both exact and heuristic algorithms computing a fragmentation that tries to minimize the impact of fragmentation on query efficiency

Part of this chapter appeared under V. Ciriani, S. De Capitani di Vimercati, S. Jajodia, S. Foresti, S. Paraboschi, P. Samarati, “Fragmentation and Encryption to Enforce Privacy in Data Storage,” in ACM Transactions on Information and System Security (TISSEC), Vol. 13:3, July, 2010 [29] ©2010 ACM, Inc. Reprinted by permission http://doi.acm.org/10.1145/1805974.1805978; and under ©2009 IEEE, reprinted, with permission, from V. Ciriani, S. De Capitani di Vimercati, S. Foresti, S. Jajodia, S. Paraboschi, P. Samarati, “Fragmentation Design for Efficient Query Execution over Sensitive Distributed Databases,” in Proc. of the 29th International Conference on Distributed Computing Systems (ICDCS 2009), Montreal, Canada, June 2009 [28].