A Survey of Privacy-Preserving Methods Across Horizontally Partitioned Data

Data mining can extract important knowledge from large data collections, but sometimes these collections are split among various parties. Data warehousing, bringing data from multiple sources under a single authority, increases risk of privacy violations. Furthermore, privacy concerns may prevent the parties from directly sharing even some meta-data. Distributed data mining and processing provide a means to address this issue, particularly if queries are processed in a way that avoids the disclosure of any information beyond the final result. This chapter describes methods to mine horizontally partitioned data without violating privacy and discusses how to use the data mining results in a privacy-preserving way. The methods described here incorporate cryptographic techniques to minimize the information shared, while adding as little as possible overhead to the mining and processing task.