Butterfly: Protecting Output Privacy in Stream Mining

Privacy preservation in data mining demands protecting both input and output privacy. The former refers to sanitizing the raw data itself before performing mining. The latter refers to preventing the mining output (model/pattern) from malicious pattern-based inference attacks. The preservation of input privacy does not necessarily lead to that of output privacy. This work studies the problem of protecting output privacy in the context of frequent pattern mining over data streams. After exposing the privacy breaches existing in current stream mining systems, the authors propose Butterfly, a light-weighted countermeasure that can effectively eliminate these breaches without explicitly detecting them, meanwhile minimizing the loss of the output accuracy.