标题： SIM模拟器：在（皮克）预算上的SIM跟踪 显示英文标题

标题： SIMulator: SIM Tracing on a (Pico-)Budget

摘要： SIM追踪——能够检查、修改和中继SIM卡和调制解调器之间的通信——已成为蜂窝网络研究中的重要技术。 它使诸如模糊通信接口、提取会话密钥、监控隐藏的SIM活动（例如，主动SIM命令或空中更新）以及通过SIM复用促进可扩展的分布式测量平台等关键的安全性和开发相关应用成为可能。 传统上，实现这些功能依赖于专用硬件，这可能会给研究人员，尤其是该领域的新人带来财务和后勤负担。 在本工作中，我们表明，仅使用简单且广泛可用的组件，如UART接口和GPIO端口，就可以实现完整的SIM追踪功能。 我们将这些功能移植到低成本的微控制器上，例如Raspberry Pi Pico（4美元）。 与其他方法不同，它通过电气隔离SIM和调制解调器并仅在APDU级别传输数据，显著降低了硬件复杂性。 通过大幅降低硬件要求和相关成本，我们的目标是使SIM追踪技术对更广泛的科研人员和爱好者群体更加可及，从而促进蜂窝网络研究中的更广泛探索和实验。 显示英文摘要

摘要： SIM tracing -- the ability to inspect, modify, and relay communication between a SIM card and modem -- has become a significant technique in cellular network research. It enables essential security- and development-related applications such as fuzzing communication interfaces, extracting session keys, monitoring hidden SIM activity (e.g., proactive SIM commands or over-the-air updates), and facilitating scalable, distributed measurement platforms through SIM reuse. Traditionally, achieving these capabilities has relied on specialized hardware, which can pose financial and logistical burdens for researchers, particularly those new to the field. In this work, we show that full SIM tracing functionality can be achieved using only simple, widely available components, such as UART interfaces and GPIO ports. We port these capabilities to low-cost microcontrollers, exemplified by the Raspberry Pi Pico (4~USD). Unlike other approaches, it dramatically reduces hardware complexity by electrically decoupling the SIM and the modem and only transferring on APDU level. By significantly reducing hardware requirements and associated costs, we aim to make SIM tracing techniques accessible to a broader community of researchers and hobbyists, fostering wider exploration and experimentation in cellular network research.