274 research outputs found
Publishing Microdata with a Robust Privacy Guarantee
Today, the publication of microdata poses a privacy threat. Vast research has
striven to define the privacy condition that microdata should satisfy before it
is released, and devise algorithms to anonymize the data so as to achieve this
condition. Yet, no method proposed to date explicitly bounds the percentage of
information an adversary gains after seeing the published data for each
sensitive value therein. This paper introduces beta-likeness, an appropriately
robust privacy model for microdata anonymization, along with two anonymization
schemes designed therefor, the one based on generalization, and the other based
on perturbation. Our model postulates that an adversary's confidence on the
likelihood of a certain sensitive-attribute (SA) value should not increase, in
relative difference terms, by more than a predefined threshold. Our techniques
aim to satisfy a given beta threshold with little information loss. We
experimentally demonstrate that (i) our model provides an effective privacy
guarantee in a way that predecessor models cannot, (ii) our generalization
scheme is more effective and efficient in its task than methods adapting
algorithms for the k-anonymity model, and (iii) our perturbation method
outperforms a baseline approach. Moreover, we discuss in detail the resistance
of our model and methods to attacks proposed in previous research.Comment: VLDB201
Individual Privacy vs Population Privacy: Learning to Attack Anonymization
Over the last decade there have been great strides made in developing
techniques to compute functions privately. In particular, Differential Privacy
gives strong promises about conclusions that can be drawn about an individual.
In contrast, various syntactic methods for providing privacy (criteria such as
kanonymity and l-diversity) have been criticized for still allowing private
information of an individual to be inferred. In this report, we consider the
ability of an attacker to use data meeting privacy definitions to build an
accurate classifier. We demonstrate that even under Differential Privacy, such
classifiers can be used to accurately infer "private" attributes in realistic
data. We compare this to similar approaches for inferencebased attacks on other
forms of anonymized data. We place these attacks on the same scale, and observe
that the accuracy of inference of private attributes for Differentially Private
data and l-diverse data can be quite similar
Towards trajectory anonymization: a generalization-based approach
Trajectory datasets are becoming popular due to the massive usage of GPS and locationbased services. In this paper, we address privacy issues regarding the identification of individuals in static trajectory datasets. We first adopt the notion of k-anonymity to trajectories and propose a novel generalization-based approach for anonymization of trajectories. We further show that releasing
anonymized trajectories may still have some privacy leaks. Therefore we propose a randomization based reconstruction algorithm for releasing anonymized trajectory data and also present how the underlying techniques can be adapted to other anonymity standards. The experimental results on real and synthetic trajectory datasets show the effectiveness of the proposed techniques
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