arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 2008.01665cs.CR
收藏

寻找失去的效用:私人位置数据

In Search of Lost Utility: Private Location Data

Szilvia Lestyán, Gergely Ács, Gergely Biczók

摘要:

训练数据的不可用是研究中许多挫折的永久来源,特别是当它是由于隐私问题时。这对于位置数据尤其如此,因为先前的技术都遭受位置轨迹的固有稀疏性和高维性,这使得大多数技术不切实际,导致不切实际的轨迹和不可扩展的方法。此外,位置访问的时间信息通常被丢弃,或者其分辨率急剧降低。在本文中,我们提出了一种新的技术,用于私下发布复合生成模型和具有详细时间信息的整个高维位置数据集。为了生成高保真度的合成数据,我们利用了车辆移动性的几个特性,例如其类似语言的特性(“你应该通过它的公司知道一个位置”)或人类如何计划从一个点到另一个点的行程。我们首先构建一个变分自编码器来生成源和目的地位置,以及相应的轨迹定时,从而对数据集的生成器分布进行建模。接下来,我们使用前馈网络计算位置之间的转移概率,并根据该模型的输出构建转移图,该图近似于源和目的地之间的所有路径的分布(在给定时间)。最后,用马尔可夫链蒙特卡罗方法从该分布中采样出一条路径。生成的合成数据集是高度真实的,可扩展的,提供了良好的实用性,但可证明是私有的。我们评估我们的模型对两个国家的最先进的方法和三个现实生活中的数据集证明我们的方法的好处。

英文摘要:

The unavailability of training data is a permanent source of much frustration in research, especially when it is due to privacy concerns. This is particularly true for location data since previous techniques all suffer from the inherent sparseness and high dimensionality of location trajectories which render most techniques impractical, resulting in unrealistic traces and unscalable methods. Moreover, time information of location visits is usually dropped, or its resolution is drastically reduced. In this paper we present a novel technique for privately releasing a composite generative model and whole high-dimensional location datasets with detailed time information. To generate high-fidelity synthetic data, we leverage several peculiarities of vehicular mobility such as its language-like characteristics ("you should know a location by the company it keeps") or how humans plan their trips from one point to the other. We model the generator distribution of the dataset by first constructing a variational autoencoder to generate the source and destination locations, and the corresponding timing of trajectories. Next, we compute transition probabilities between locations with a feed forward network, and build a transition graph from the output of this model, which approximates the distribution of all paths between the source and destination (at a given time). Finally, a path is sampled from this distribution with a Markov Chain Monte Carlo method. The generated synthetic dataset is highly realistic, scalable, provides good utility and, nonetheless, provably private. We evaluate our model against two state-of-the-art methods and three real-life datasets demonstrating the benefits of our approach.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑