July 26 10:50AMOutsourcing the training of support vector machines (SVM) to external service providers benefits the data owner who is not familiar with the techniques of the SVM or has limited computing resources. In outsourcing, the data privacy is a critical issue for some legal or commercial reasons since there may be sensitive information contained in the data. Existing privacy-preserving SVM works are either not applicable to outsourcing or weak in security. In this paper, we propose a scheme for privacy-preserving outsourcing the training of the SVM without disclosing the actual content of the data to the service provider. In the proposed scheme, the data sent to the service provider is perturbed by a random transformation, and the service provider trains the SVM for the data owner from the perturbed data. The proposed scheme is stronger in security than existing techniques, and incurs very little redundant communication and computation cost." Invited Talk Abstract
July 26 2:01PMFor any outsourcing service, privacy is a major concern. This paper focuses on outsourcing frequent itemset mining and examines the issue on how to protect privacy against the case where the attackers have precise knowledge on the supports of some items. We propose a new approach referred to as k-support anonymity to protect each sensitive item with k-1 other items of similar support. To achieve k-support anonymity, we introduce a pseudo taxonomy tree and have the third party mine the generalized frequent itemsets under the corresponding generalized association rules instead of association rules. The pseudo taxonomy is a construct to facilitate hiding of the original items, where each original item can map to either a leaf node or an internal node in the taxonomy tree. The rationale for this approach is that with a taxonomy tree, the k nodes to satisfy the k-support anonymity may be any k nodes in the taxonomy tree with the appropriate supports. So this approach can provide more candidates for k-support anonymity with limited fake items as only the leaf nodes, not the internal nodes, of the taxonomy tree need to appear in the transactions. Otherwise for the association rule mining, the k nodes to satisfy the k-support anonymity have to correspond to the leaf nodes in the taxonomy tree. This is far more restricted. The challenge is thus on how to generate the pseudo taxonomy tree to facilitate k-support anonymity and to ensure the conservation of original frequent itemsets. The experimental results showed that our methods of k-support anonymity can achieve very good privacy protection with moderate storage overhead.