On the privacy offered by (k, δ)-anonymity

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摘要

The widespread deployment of technologies with tracking capabilities, like GPS, GSM, RFID and on-line social networks, allows mass collection of spatio-temporal data about their users. As a consequence, several methods aimed at anonymizing spatio-temporal data before their publication have been proposed in recent years. Such methods are based on a number of underlying privacy models. Among these models, (k,δ)-anonymity claims to extend the widely used k-anonymity concept by exploiting the spatial uncertainty δ≥0 in the trajectory recording process. In this paper, we prove that, for any δ>0 (that is, whenever there is actual uncertainty), (k,δ)-anonymity does not offer trajectory k-anonymity, that is, it does not hide an original trajectory in a set of k indistinguishable anonymized trajectories. Hence, the methods based on (k,δ)-anonymity, like Never Walk Alone (NWA) and Wait For Me (W4M) can offer trajectory k-anonymity only when δ=0 (no uncertainty). Thus, the idea of exploiting the recording uncertainty δ to achieve trajectory k-anonymity with information loss inversely proportional to δ turns out to be flawed.

论文关键词:Spatio-temporal data,Trajectory,Data privacy,Anonymity,Uncertainty

论文评审过程:Received 30 November 2012, Accepted 4 December 2012, Available online 20 December 2012.

论文官网地址:https://doi.org/10.1016/j.is.2012.12.003