CrossLink：通过跨协议链接设备标识符打破位置隐私

中文摘要 AI 辅助

智能手机同时通过LTE、WiFi和BLE传输临时标识符。现有的隐私防御措施按协议分析标识符随机化，隐含地假设这些保护措施在协议间是组合的。我们表明事实并非如此：即使每个协议仅泄露临时标识符且对手完全被动，不同步的标识符轮换也允许跨协议拼接设备轨迹。我们提出CrossLink，一种不确定性感知的追踪算法，在噪声定位和移动性下跨时间、空间和协议链接标识符。我们使用商用设备的受控实验室实验和大规模移动性模拟评估CrossLink。在大规模移动性模拟下，CrossLink为83%的用户重建完整轨迹，而最佳单协议基线仅为22%，表明位置隐私必须跨协议联合分析。我们进一步表明，CrossLink在部分覆盖下仍然有效：战略性地放置在LTE切换区域附近的嗅探器、移动嗅探器和有限的高覆盖子区域保留了足够的跨协议证据以弥合观测间隙，实现比随机部署显著更高的可链接性。

英文摘要

Smartphones simultaneously transmit temporary identifiers over LTE, WiFi, and BLE. Existing privacy defenses analyze identifier randomization per protocol, implicitly assuming that these protections compose across protocols. We show that they do not: Even when each protocol leaks only temporary identifiers and the adversary is fully passive, unsynchronized identifier rotations allow cross-protocol stitching of device traces. We present CrossLink, an uncertainty-aware tracing algorithm that links identifiers across time, space, and protocols under noisy localization and mobility. We evaluate CrossLink using controlled lab experiments with commodity devices and large-scale mobility simulation. Under large-scale mobility simulation, CrossLink reconstructs full traces for 83% of users, versus 22% for the best single-protocol baseline, showing that location privacy must be analyzed jointly across protocols. We further show that CrossLink remains effective under partial coverage: strategically placed sniffers near LTE handover regions, mobile sniffers, and limited high-coverage subregions retain sufficient cross-protocol evidence to bridge observation gaps, achieving substantially higher linkability than random deployments.

发表机构

• CISPA Helmholtz Center for Information Security（CISPA赫尔姆霍兹信息安全中心）
• Saarland University（萨尔兰州立大学）

机构由 AI 辅助整理，请以论文原文为准。