The application of digital tracking mechanism introduces a series of leakage problems of users' personal sensitive information related to the trajectory. Therefore, we propose a secure storage scheme for trajectory data. Firstly, four-dimensional spatiotemporal clustering of the trajectory data is performed to reduce the spatiotemporal complexity of data storage. Secondly, the privacy level of the trajectory data in the clusters is measured individually, which ensures the needs for personalized privacy protection are met. Finally, a noise trajectory (NTR) tree based on differential privacy is constructed, and the allocation of privacy budget and noise addition are optimized. Extensive simulations show that our scheme improves in terms of time efficiency, and achieves a flexible and effective balance between data accuracy and privacy.

中文翻译：

---

数字跟踪机构轨迹数据安全存储方案

数字化追踪机制的应用引入了用户与轨迹相关的个人敏感信息的一系列泄露问题。因此，我们提出了一种轨迹数据的安全存储方案。首先，对轨迹数据进行四维时空聚类，降低数据存储的时空复杂度。其次，对集群内轨迹数据的隐私级别进行了单独度量，保证了个性化隐私保护的需求。最后，构建了基于差分隐私的噪声轨迹（NTR）树，并对隐私预算分配和噪声添加进行了优化。大量仿真表明，我们的方案在时间效率方面有所提高，并在数据准确性和隐私之间实现了灵活有效的平衡。