论文标题
实用隐私保护POI建议
Practical Privacy Preserving POI Recommendation
论文作者
论文摘要
最近已经对利益点(POI)的建议进行了广泛的研究并成功地应用于行业。但是,大多数现有方法基于收集用户数据建立集中模型。私人数据和模型均由推荐人持有,这引起了严重的隐私问题。在本文中,我们提出了一个新颖的隐私保护POI建议(PRIREC)框架。首先,为了保护数据隐私,用户的私人数据(功能和操作)保持在自己的一边,例如手机或垫子。同时,建议将所有用户保留所有用户需要访问公共数据,以降低用户设备的存储成本。这些公共数据包括:(1)仅与POI状态有关的静态数据,例如POI类别,(2)动态数据取决于用户POI操作,例如访问的计数。动态数据可能很敏感,我们开发了当地的差异隐私技术,以通过隐私保证将此类数据发布给公众。其次,PRIREC遵循由线性模型和特征相互作用模型组成的分解机(FM)的表示。为了保护模型隐私,线性模型保存在用户方面,我们提出了一个安全的分散梯度下降协议,供用户协作学习。由于没有隐私风险,因此推荐人保留了功能交互模型,并且我们在联合学习范式中采用安全的聚合策略来学习它。为此,PRIREC将用户的私人原始数据和模型保留在用户自己的手中,并在很大程度上保护用户隐私。我们将PRIREC应用于现实世界数据集中,全面的实验表明,与FM相比,PRIREC可以达到可比甚至更好的建议准确性。
Point-of-Interest (POI) recommendation has been extensively studied and successfully applied in industry recently. However, most existing approaches build centralized models on the basis of collecting users' data. Both private data and models are held by the recommender, which causes serious privacy concerns. In this paper, we propose a novel Privacy preserving POI Recommendation (PriRec) framework. First, to protect data privacy, users' private data (features and actions) are kept on their own side, e.g., Cellphone or Pad. Meanwhile, the public data need to be accessed by all the users are kept by the recommender to reduce the storage costs of users' devices. Those public data include: (1) static data only related to the status of POI, such as POI categories, and (2) dynamic data depend on user-POI actions such as visited counts. The dynamic data could be sensitive, and we develop local differential privacy techniques to release such data to public with privacy guarantees. Second, PriRec follows the representations of Factorization Machine (FM) that consists of linear model and the feature interaction model. To protect the model privacy, the linear models are saved on users' side, and we propose a secure decentralized gradient descent protocol for users to learn it collaboratively. The feature interaction model is kept by the recommender since there is no privacy risk, and we adopt secure aggregation strategy in federated learning paradigm to learn it. To this end, PriRec keeps users' private raw data and models in users' own hands, and protects user privacy to a large extent. We apply PriRec in real-world datasets, and comprehensive experiments demonstrate that, compared with FM, PriRec achieves comparable or even better recommendation accuracy.