Kaichen Yang

dblp:157/9274 · DBLP profile ↗
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12ranked-venue papers
4as first author
9since 2021 · last 2026
0000-0003-1027-6708ORCID · corroborated

Domains — the database's venue-derived domains; a paper can count in several

Systems, architecture and hardware · 6 · 1 first-author · 6 since 2021Artificial intelligence and machine learning · 4 · 2 first-author · 2 since 2021Graphics, computer vision, multimedia, augmented reality and games · 4 · 2 first-author · 2 since 2021Security and privacy · 2 · 1 first-author · 1 since 2021
YearPublicationVenuePosition
2026 Dynamic Deep Prompt Optimization for Defending Against Jailbreak Attacks on LLMs
abstract
Large Language Models (LLMs) demonstrate impressive capabilities across many applications but remain vulnerable to jailbreak attacks, which elicit harmful or unintended content. While model fine-tuning is an option for safety alignment, it is costly and prone to catastrophic forgetting. Prompt optimization has emerged as a promising alternative, yet existing prompt-based defenses typically rely on static modifications (e.g., fixed prefixes or suffixes) that cannot adapt to diverse and evolving attacks. We propose Dynamic Deep Prompt Optimization (DDPO), the first jailbreak defense based on deep prompt optimization. DDPO uses the target LLM's own intermediate layers as feature extractors to dynamically generate defensive embeddings via a lightweight multilayer perceptron. These tailored embeddings are then injected into a subsequent intermediate layer, enabling an input-dependent defense without modifying the LLM's weights. This design ensures high adaptability with minimal computational overhead. Experiments on a diverse set of models and attacks demonstrate that DDPO significantly outperforms static prompt optimization methods, particularly on weakly aligned models and when handling semantically ambiguous benign prompts, successfully distinguishing them from genuinely harmful requests.
Doniyorkhon Obidov, Honggang Yu, Kaichen Yang
AAAI4
2025 PIAD: Pose and Illumination agnostic Anomaly Detection
abstract
We introduce the Pose and Illumination agnostic Anomaly Detection (PIAD) problem, a generalization of pose-agnostic anomaly detection (PAD). Being illumination agnostic is critical, as it relaxes the assumption that training data for an object has to be acquired in the same light configuration of the query images that we want to test. Moreover, even if the object is placed within the same capture environment, being illumination agnostic implies that we can relax the assumption that the relative pose between environment light and query object has to match the one in the training data. We introduce a new dataset to study this problem, containing both synthetic and real-world examples, propose a new baseline for PIAD, and demonstrate how our baseline provides state-of-the-art results in both PAD and PIAD, not only in the new proposed dataset, but also in existing datasets that were designed for the simpler PAD problem. Project page: https://kaichen-yang.github.io/piad/.
Kaichen Yang, Junjie Cao 0001, Zeyu Bai, Zhixun Su, Andrea Tagliasacchi
CVPR1
2025 Building Reasoning LLMs for Hardware Design Generation via Function-Aligned Differentiated Revision
abstract
Recent advances in large language models have significantly improved the capabilities of programming. While these models excel at generating valid software, applying them to the hardware domain remains challenging due to the intrinsic complexity and strict structural semantics required in hardware design. Current LLM approaches for hardware generation typically focus on direct generation. This often results in hardware implementations with functional errors or structural flaws. To overcome these limitations, we propose a reasoning-enhanced training framework explicitly tailored for hardware generation tasks. Our multi-stage methodology combines systematic dataset curation via compilation filtering (achieving a 100% pass rate compared to 27 − 44% in existing datasets), Function-Aligned Differentiated Revision for comparative annotation across five RTL-relevant dimensions, supervised fine-tuning using reasoning prompts, and reinforcement learning guided by Verilator Parser. Our experiments show that explicitly incorporating reasoning substantially enhances the structural integrity and functional correctness of generated hardware designs, improving pass@1 rates by up to 20% on VerilogEval Human benchmarks and reproducing the "Aha moment", where the model explicitly organizes ideas before generation. Our work demonstrates that smaller, specialized reasoning models (1.5B parameters) can effectively augment larger open-source language models through reasoning transfer.
Weimin Fu, Shijie Li 0009, Kaichen Yang, Xuan Silvia Zhang, Yier Jin, Xiaolong Guo 0001
ICCAD3
2025 Siamese: Stealing Fine-Tuned Visual Foundation Models via Diversified Prompting
abstract
Visual foundation models, characterized by their robust generalization and adaptability, serve as the basis for a wide array of downstream tasks. When fine-tuned for specific tasks, these models encapsulate confidential and valuable task-specific knowledge, making them prime targets for model stealing (MS) attacks. While recent efforts have exposed MS threats in practical scenarios such as data-free and hard-label contexts, these attacks predominantly target traditional victim models trained from scratch. Fine-tuned visual foundation models, pre-trained on vast and diverse datasets and then fine-tuned on downstream tasks, present significant challenges for traditional MS attacks to extract task-specific knowledge. In this paper, we introduce an innovative MS attack, named SIAMESE, to steal fine-tuned visual foundation models under black-box, data-free, and hard-label settings. The core approach of SIAMESE involves constructing a stolen model using a foundation model that is efficiently and concurrently fine-tuned with multiple diversified soft prompts. To integrate the knowledge derived from these prompts, we propose a novel and tractable loss function that analyzes the output distributions while enforcing orthogonality among the prompts to minimize interference. Additionally, a unique alignment module enhances SIAMESE by synchronizing interpretations between the victim and stolen models. Extensive experiments validate that SIAMESE outperforms state-of-the-art baseline attacks over 10% in accuracy, exposing the heightened vulnerability of fine-tuned visual foundation models to MS threats.
Madhureeta Das, Gaurav Bagwe, Miao Pan, Kaichen Yang, Xiaoyong Yuan, Lan Zhang 0005
SEC4
2025 A Generalize Hardware Debugging Approach for Large Language Models Semi-Synthetic, Datasets
abstract
Large Language Models (LLMs) have precipitated emerging trends towards intelligent automation. However, integrating LLMs into the hardware debug domain encounters challenges: the datasets for LLMs for hardware are often plagued by a dual dilemma – scarcity and subpar quality. Traditional hardware debug approaches that rely on experienced labor to generate detailed prompts are not cheaply scalable. Similarly, strategies that depend on existing LLMs and randomly generated prompts fail to achieve sufficient reliability. We propose a directed, semi-synthetic data synthetic method that leverages version control information and journalistic event descriptions. To produce high-quality data, this approach utilizes version control data from hardware projects combined with the 5W1H (Who, What, When, Where, Why, How) journalistic principles. It facilitates the linear scaling of dataset volumes without depending on skilled labor. We have implemented this method on a collected dataset of open-source hardware designs and fine-tuned fifteen general-purpose LLMs to enable their capability in hardware debugging tasks, thereby validating the efficacy of our approach.
Weimin Fu, Shijie Li 0009, Yifang Zhao, Kaichen Yang, Xuan Zhang 0001, Yier Jin, Xiaolong Guo 0001
IEEE Trans. Circuits Syst. I Regul. Pap.4
2024 Hardware Phi-1.5B: A Large Language Model Encodes Hardware Domain Specific Knowledge
abstract
In the rapidly evolving semiconductor industry, where research, design, verification, and manufacturing are intricately linked, the potential of Large Language Models to revolutionize hardware design and security verification is immense. The primary challenge, however, lies in the complexity of hardware-specific issues that are not adequately addressed by the natural language or software code knowledge typically acquired during the pretraining stage. Additionally, the scarcity of datasets specific to the hardware domain poses a significant hurdle in developing a foundational model. Addressing these challenges, this paper introduces Hardware Phi-1.5B, an innovative large language model specifically tailored for the hardware domain of the semiconductor industry. We have developed a specialized, tiered dataset—comprising small, medium, and large subsets—and focused our efforts on pretraining using the medium dataset. This approach harnesses the compact yet efficient architecture of the Phi-1.5B model. The creation of this first pre-trained, hardware domain-specific large language model marks a significant advancement, offering improved performance in hardware design and verification tasks and illustrating a promising path forward for AI applications in the semiconductor sector.
Weimin Fu, Shijie Li 0009, Yifang Zhao, Haocheng Ma, Raj Gautam Dutta, Xuan Zhang 0001, Kaichen Yang, Yier Jin, Xiaolong Guo 0001
ASPDAC7
2022 Graph Neural Network based Hardware Trojan Detection at Intermediate Representative for SoC Platforms
abstract
The rapid growth of the Internet of Things (IoT) industry has increased the demand for intellectual property (IP) cores. Increasing numbers of third-party vendors have raised security concerns for System-on-Chip (SoC) designers. With the growing complexity of SoC design, the workload is overwhelming for SoC designers to diagnose security vulnerabilities manually. Almost all existing SoC platforms are developed using SystemVerilog. However, there is a lack of reliable security static analysis tools for directly processing the SystemVerilog program. Due to its open-source, flexibility and extendability, RISC-V CPU has become an ideal platform for the IoT applications such as wearable devices, entertainment, smart thermostats, etc. As a result, assuring the trustworthiness of a given RISC-V system is highly desired. This paper proposes a graph neural network-based Trojan detection framework to protect the RISC-V SoC platform written in SystemVerilog from intruding malicious logic. The study is under-construction and planned to be validated on the Ariane RISC-V CPU with several peripheral IPs in the experimental section.
Weimin Fu, Honggang Yu, Orlando Arias, Kaichen Yang, Yier Jin, Tuba Yavuz, Xiaolong Guo 0001
ACM Great Lakes Symposium on VLSI4
2021 Robust Roadside Physical Adversarial Attack Against Deep Learning in Lidar Perception Modules
abstract
As Autonomous Vehicles (AVs) mature into viable transportation solutions, mitigating potential vehicle control security risks becomes increasingly important. Perception modules in AVs combine multiple sensors to perceive the surrounding environment. As such, they have been the focus of efforts to exploit the aforementioned risks due to their critical role in controlling autonomous driving technology. Despite extensive and thorough research into the vulnerability of camera-based sensors, vulnerabilities originating from Lidar sensors and their corresponding deep learning models in AVs remain comparatively untouched. Being aware that small roadside objects can be occasionally incorrectly identified as vehicles through on-board deep learning models, we propose a novel adversarial attack inspired by this phenomenon in both white-box and black-box scenarios. The adversarial attacks proposed in this paper are launched against deep learning models that perform object detection tasks through raw 3D points collected by a Lidar sensor in an autonomous driving scenario. In comparison to existing works, our attack creates not only adversarial point clouds in simulated environments, but also robust adversarial objects that can cause behavioral reactions in state of the art autonomous driving systems. Defense methods are then proposed and evaluated against this type of adversarial objects.
Kaichen Yang, Tzungyu Tsai, Honggang Yu, Max Panoff, Tsung-Yi Ho, Yier Jin
AsiaCCS1
2021 3D-Adv: Black-Box Adversarial Attacks against Deep Learning Models through 3D Sensors
abstract
The combination of deep learning techniques and commercial 3D sensors reveal a bright future as they provide a low cost and convenient method to collect and analyze depth information from the environment for various applications ranging from industrial modeling to mobile face recognition. Despite the abundant research devoted to the development of more accurate, flexible and efficient machine learning schemes as well as 3D sensors, security concerns related to these techniques remain largely untouched. In this paper, we propose a novel adversarial attack against this combination by showing that deep learning models with popular 3D sensors may misclassify real objects in the physical environment. Comparing to the existing attack algorithms against deep learning models developed for 3D data analysis that only consider digital point cloud data and single deep learning model, our attacks target popular commercial 3D sensors combined with various deep learning schemes in the black-box setting. Experimental results demonstrate that our 3D printed adversarial objects stay effective after scanned by a 3D sensor.
Kaichen Yang, Xuan-Yi Lin, Tsung-Yi Ho, Yier Jin
DAC1
2020 Robust Adversarial Objects against Deep Learning Models
abstract
Previous work has shown that Deep Neural Networks (DNNs), including those currently in use in many fields, are extremely vulnerable to maliciously crafted inputs, known as adversarial examples. Despite extensive and thorough research of adversarial examples in many areas, adversarial 3D data, such as point clouds, remain comparatively unexplored. The study of adversarial 3D data is crucial considering its impact in real-life, high-stakes scenarios including autonomous driving. In this paper, we propose a novel adversarial attack against PointNet++, a deep neural network that performs classification and segmentation tasks using features learned directly from raw 3D points. In comparison to existing works, our attack generates not only adversarial point clouds, but also robust adversarial objects that in turn generate adversarial point clouds when sampled both in simulation and after construction in real world. We also demonstrate that our objects can bypass existing defense mechanisms designed especially against adversarial 3D data.
Tzungyu Tsai, Kaichen Yang, Tsung-Yi Ho, Yier Jin
AAAI2
2020 Beyond Digital Domain: Fooling Deep Learning Based Recognition System in Physical World
abstract
Adversarial examples that can fool deep neural network (DNN) models in computer vision present a growing threat. The current methods of launching adversarial attacks concentrate on attacking image classifiers by adding noise to digital inputs. The problem of attacking object detection models and adversarial attacks in physical world are rarely touched. Some prior works are proposed to launch physical adversarial attack against object detection models, but limited by certain aspects. In this paper, we propose a novel physical adversarial attack targeting object detection models. Instead of simply printing images, we manufacture real metal objects that could achieve the adversarial effect. In both indoor and outdoor experiments we show our physical adversarial objects can fool widely applied object detection models including SSD, YOLO and Faster R-CNN in various environments. We also test our attack in a variety of commercial platforms for object detection and demonstrate that our attack is still valid on these platforms. Consider the potential defense mechanisms our adversarial objects may encounter, we conduct a series of experiments to evaluate the effect of existing defense methods on our physical attack.
Kaichen Yang, Tzungyu Tsai, Honggang Yu, Tsung-Yi Ho, Yier Jin
AAAI1
2020 CloudLeak: Large-Scale Deep Learning Models Stealing Through Adversarial Examples
Honggang Yu, Kaichen Yang, Teng Zhang 0002, Yun-Yun Tsai, Tsung-Yi Ho, Yier Jin
NDSS2