CheolJun Park

LTE sniffers are important for security and performance analysis because they can passively capture the wireless traffic of users in LTE network. However, existing open-source LTE sniffers have only limited functionality and cannot decode data traffic. This paper introduces LTESNIFFER, the first open-source LTE sniffer that can passively decode both uplink and downlink data traffic. Implementing a sniffer is not trivial because one needs to understand detailed configurations and parameters to su

Cellular basebands play a crucial role in mobile communication. However, it is significantly challenging to assess their security for several reasons. Manual analysis is inevitable because of the obscurity and complexity of baseband firmware; however, such analysis requires repetitive efforts to cover diverse models or versions. Automating the analysis is also non-trivial because the firmware is significantly large and contains numerous functions associated with complex cellular protocols. There

This paper presents a miniature electromagnetic (EM) sensor node for wireless surgical navigation systems. The sensor node measures the intensity of the EM field originated from the EM field generator placed at the predefined position and determines the position and orientation of the object where the sensor node is attached. The wireless electromagnetic sensor node performs analog and digital signal processing as well as wireless communication. The EM field signal from the generator is detected

As the air quality becomes one of important factors in human life, interest in the development of good gas sensor systems is steadily increasing. Accordingly, the importance of the interface integrated circuit (IC) for metal-oxide gas sensors also increases. For the implementation of smart gas sensor systems, circuit designers need to consider several factors such as power consumption, detection range, size, and selectivity, simultaneously. In this paper, we review the operation principle and sy

The electromagnetic (EM) sensor system is one of most widely-used sensor systems for object localization. A distinct advantage of providing position and orientation information without line-of-sight configuration makes the EM sensor system applicable to various fields such as motion detection, object tracking, and sports posture analysis. The sensor measures the intensity of electromagnetic field from the field generator, which can be converted into the position and orientation information after

A variety of neurological therapeutic devices and brain machine interface applications have increased the need of closed-loop neuromodulation systems. The closed-loop system requires a bidirectional neural interface which can perform both recording and stimulation functions. In such a system, large artifacts caused by high-voltage stimulation strongly interfere the recording operation, which needs to acquire very weak neural signals. As a result, the dynamic range, or the span of the signal magn

Cellular baseband processors represent critical security components in modern mobile devices, yet they remain challenging to analyze due to their complexity and restricted access. Recent advances in baseband research introduced FirmWire, the state-of-the-art emulator enabling full-system baseband emulation with extensive features debugging capabilities. However, it lacks protocol state awareness, significantly limiting its coverage and fidenlity. While implementing such support demands substanti

Baseband processors (BPs) in cellular devices implement complex radio protocols, and memory corruption vulnerabilities in these implementations can lead to critical security breaches, including remote code execution. Traditional approaches to detecting such vulnerabilities rely on reverse engineering or emulation. However, these methods face significant scalability challenges due to proprietary firmware and architectural complexities. Over-the-air (OTA) testing offers broader applicability but p

Cellular networks increasingly support critical infrastructure, yet their security remains an ongoing concern. While prior research has focused mainly on downlink vulnerabilities, uplink security—how user equipment (UE) affects the core network—has received limited attention. We study a class of uplink vulnerabilities, which we define as context integrity violations (CIVs), where an unauthenticated or improperly authenticated UE modifies the internal state of other subscribers. Prior work identi