arXiv subjects

Chuxiong Wu

Publications and source records attributed to Chuxiong Wu.

4 recordsLinked to original sources

arXiv2025

Touch to Pair: Secure and Usable IoT Pairing without Information Loss

Secure pairing is essential for trustworthy deployment and operation of Internet of Things (IoT) devices. However, traditional pairing methods are unsuitable due to the lack of user interfaces such as keyboards. Proximity-based approaches are usable but vulnerable to nearby attackers, while methods relying on physical operations (e.g., shaking) offer higher security but require inertial sensors that most IoT devices lack. We introduceUniversal Operation Sensing, which enables IoT devices to detect user operations without inertial sensors. With this technique, users can complete pairing within seconds through simple actions, such as pressing a button or twisting a knob, using either a smartphone or a smartwatch. We further identify an accuracy issue caused by information loss in the commonly used fuzzy-commitment protocol. To address this issue, we propose TimeWall, an accurate pairing protocol that avoids fuzzy commitment and incurs zero information loss. A comprehensive evaluation shows that it is secure, usable, and efficient.

cs.CR↗

arXiv2025

Impact of Fine-Tuning Methods on Memorization in Large Language Models

As the capabilities of pre-trained large language models (LLMs) continue to advance, the "pre-train and fine-tune" paradigm has become increasingly mainstream, leading to the development of various fine-tuning methods. However, the privacy risks arising from memorization during fine-tuning have received relatively little attention. To address this gap, we categorize popular fine-tuning approaches and assess their impact on memorization through the lens of membership inference attacks (MIAs). Our results show that, compared to parameter-based fine-tuning, prompt-based fine-tuning achieves competitive performance while exhibiting lower vulnerability to MIAs. Furthermore, prompt-based methods maintain low memorization regardless of model scale. These findings suggest that parameter-based fine-tuning is more prone to leaking private information, whereas prompt-based fine-tuning serves as a more privacy-preserving option.

cs.CL↗

arXiv2025

StealthInk: A Multi-bit and Stealthy Watermark for Large Language Models

Watermarking for large language models (LLMs) offers a promising approach to identifying AI-generated text. Existing approaches, however, either compromise the distribution of original generated text by LLMs or are limited to embedding zero-bit information that only allows for watermark detection but ignores identification. We present StealthInk, a stealthy multi-bit watermarking scheme that preserves the original text distribution while enabling the embedding of provenance data, such as userID, TimeStamp, and modelID, within LLM-generated text. This enhances fast traceability without requiring access to the language model's API or prompts. We derive a lower bound on the number of tokens necessary for watermark detection at a fixed equal error rate, which provides insights on how to enhance the capacity. Comprehensive empirical evaluations across diverse tasks highlight the stealthiness, detectability, and resilience of StealthInk, establishing it as an effective solution for LLM watermarking applications.

cs.CR↗

arXiv2024

Turning Noises to Fingerprint-Free "Credentials": Secure and Usable Drone Authentication

Drones have been widely used in various services, such as delivery and surveillance. Authentication forms the foundation of the security of these services. However, drones are expensive and may carry important payloads. To avoid being captured by attackers, drones should keep a safe distance from the verifier before authentication succeeds. This makes authentication methods that only work in very close proximity not applicable. Our work leverages drone noises for authentication. While using sounds for authentication is highly usable, how to handle various attacks that manipulate sounds is an \emph{unresolved challenge}. It is also unclear how to ensure robustness under various environmental sounds. Being the first in the literature, we address the two major challenges by exploiting unique characteristics of drone noises. We thereby build an authentication system that does \emph{not} rely on any drone sound fingerprints, keeps resilient to attacks, and is robust under environmental sounds. An extensive evaluation demonstrates its security and usability.

cs.CR↗