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Xuandong Zhao

36 accepted papers

2026

AgentSynth: Scalable Task Generation for Generalist Computer-Use Agents

ICLR 2026poster

We introduce AgentSynth, a scalable and cost-efficient pipeline for automatically synthesizing high-quality tasks and trajectory datasets for generalist computer-use agents. Leveraging information asymmetry, AgentSynth constructs subtasks that are simple during generation but significantly more chal…

Cited by 0SourcecodeScholar
2026

In-Context Watermarks for Large Language Models

ICLR 2026poster

The growing use of large language models (LLMs) for sensitive applications has highlighted the need for effective watermarking techniques to ensure the provenance and accountability of AI-generated text. However, most existing watermarking methods require access to the decoding process, limiting the…

Cited by 0SourcecodeScholar
2026

Position: Invisible Tokens, Visible Bills: The Urgent Need to Audit Hidden Operations in Opaque LLM Services

ICML 2026poster

Modern large language model (LLM) services increasingly rely on complex, often abstract operations, such as multi-step reasoning and multi-agent collaboration, to generate high-quality outputs. While users are billed based on token consumption and API usage, these internal steps are typically not vi…

Cited by 0SourceScholar
2026

Terminal-Bench: Benchmarking Agents on Hard, Realistic Tasks in Command Line Interfaces

ICLR 2026poster

AI agents may soon become capable of autonomously completing valuable, long-horizon tasks in diverse domains. Current benchmarks either do not measure real-world tasks, or are not sufficiently difficult to meaningfully measure frontier models. To this end, we present Terminal-Bench 1.5: a carefully…

Cited by 0SourcecodeScholar
2025

A Practical Examination of AI-Generated Text Detectors for Large Language Models

NAACL 2025findings

The proliferation of large language models has raised growing concerns about their misuse, particularly in cases where AI-generated text is falsely attributed to human authors. Machine-generated content detectors claim to effectively identify such text under various conditions and from any language…

Cited by 1SourcePDFScholar
2025

A Technical Report on “Erasing the Invisible”: The 2024 NeurIPS Competition on Stress Testing Image Watermarks

NeurIPS 2025poster

AI-generated images have become pervasive, raising critical concerns around content authenticity, intellectual property, and the spread of misinformation. Invisible watermarks offer a promising solution for identifying AI-generated images, preserving content provenance without degrading visual quali…

Cited by 0SourceScholar
2025

AGENTVIGIL: Automatic Black-Box Red-teaming for Indirect Prompt Injection against LLM Agents

EMNLP 2025

There emerges a critical security risk of LLM agents: indirect prompt injection, a sophisticated attack vector that compromises thecore of these agents, the LLM, by manipulating contextual information rather than direct user prompts. In this work, we propose a generic black-box optimization framewor

Cited by 0SourcePDFScholar
2025

CodeHalu: Investigating Code Hallucinations in LLMs via Execution-based Verification

AAAI 2025technical

Large Language Models (LLMs) have made significant progress in code generation, offering developers groundbreaking automated programming support. However, LLMs often generate code that is syntactically correct and even semantically plausible, but may not execute as expected or fulfill specified requ…

2025

DIS-CO: Discovering Copyrighted Content in VLMs Training Data

ICML 2025poster

*How can we verify whether copyrighted content was used to train a large vision-language model (VLM) without direct access to its training data?* Motivated by the hypothesis that a VLM is able to recognize images from its training corpus, we propose DIS-CO, a novel approach to infer the inclusion of…

2025

Efficiently Identifying Watermarked Segments in Mixed-Source Texts

ACL 2025long

Text watermarks in large language models (LLMs) are increasingly used to detect synthetic text, mitigating misuse cases like fake news and academic dishonesty. While existing watermarking detection techniques primarily focus on classifying entire documents as watermarked or not, they often neglect t…

2025

Improving LLM Safety Alignment with Dual-Objective Optimization

ICML 2025poster

Existing training-time safety alignment techniques for large language models (LLMs) remain vulnerable to jailbreak attacks. Direct preference optimization (DPO), a widely deployed alignment method, exhibits limitations in both experimental and theoretical contexts as its loss function proves subopti…

2025

MMDT: Decoding the Trustworthiness and Safety of Multimodal Foundation Models

ICLR 2025poster

Multimodal foundation models (MMFMs) play a crucial role in various applications, including autonomous driving, healthcare, and virtual assistants. However, several studies have revealed vulnerabilities in these models, such as generating unsafe content by text-to-image models. Existing benchmarks o…

2025

Multimodal Situational Safety

ICLR 2025poster

Multimodal Large Language Models (MLLMs) are rapidly evolving, demonstrating impressive capabilities as multimodal assistants that interact with both humans and their environments. However, this increased sophistication introduces significant safety concerns. In this paper, we present the first eval…

Cited by 5SourcePDFScholar
2025

OVERT: A Benchmark for Over-Refusal Evaluation on Text-to-Image Models

NeurIPS 2025poster

Text-to-Image (T2I) models have achieved remarkable success in generating visual content from text inputs. Although multiple safety alignment strategies have been proposed to prevent harmful outputs, they often lead to overly cautious behavior ---rejecting even benign prompts---a phenomenon known as…

Cited by 0SourcecodeScholar
2025

Permute-and-Flip: An optimally stable and watermarkable decoder for LLMs

ICLR 2025poster

In this paper, we propose a new decoding method called Permute-and-Flip (PF) decoder. It enjoys stability properties similar to the standard sampling decoder, but is provably up to 2x better in its quality-stability tradeoff than sampling and never worse than any other decoder. We also design a cryp…

2025

SafeKey: Amplifying Aha-Moment Insights for Safety Reasoning

EMNLP 2025

Large Reasoning Models (LRMs) introduce a new generation paradigm of explicitly reasoning before answering, leading to remarkable improvements in complex tasks. However, they pose great safety risks against harmful queries and adversarial attacks. While recent mainstream safety efforts on LRMs, supe

2025

Scalable Best-of-N Selection for Large Language Models via Self-Certainty

NeurIPS 2025poster

Best-of-N selection is a key technique for improving the reasoning performance of Large Language Models (LLMs) through increased test-time computation. Current state-of-the-art methods often employ computationally intensive reward models for response evaluation and selection. Reward-free alternative…

Cited by 0SourcecodeScholar
2025

Weak-to-Strong Jailbreaking on Large Language Models

ICML 2025poster

Large language models (LLMs) are vulnerable to jailbreak attacks -- resulting in harmful, unethical, or biased text generations. However, existing jailbreaking methods are computationally costly. In this paper, we propose the **weak-to-strong** jailbreaking attack, an efficient inference time attack…

2024

A Survey on Detection of LLMs-Generated Content

EMNLP 2024finding

The burgeoning capabilities of advanced large language models (LLMs) such as ChatGPT have led to an increase in synthetic content generation with implications across a variety of sectors, including media, cybersecurity, public discourse, and education. As such, the ability to detect LLMs-generated c…

2024

Bileve: Securing Text Provenance in Large Language Models Against Spoofing with Bi-level Signature

NeurIPS 2024poster

Text watermarks for large language models (LLMs) have been commonly used to identify the origins of machine-generated content, which is promising for assessing liability when combating deepfake or harmful content. While existing watermarking techniques typically prioritize robustness against removal…

2024

DE-COP: Detecting Copyrighted Content in Language Models Training Data

ICML 2024poster

*How can we detect if copyrighted content was used in the training process of a language model, considering that the training data is typically undisclosed?* We are motivated by the premise that a language model is likely to identify verbatim excerpts from its training text. We propose DE-COP, a met…

2024

GumbelSoft: Diversified Language Model Watermarking via the GumbelMax-trick

ACL 2024long

Large language models (LLMs) excellently generate human-like text, but also raise concerns about misuse in fake news and academic dishonesty. Decoding-based watermark, particularly the watermark based on the GumbelMax trick (GM watermark), is a standout solution for safeguarding machine-generated te…

2024

Invisible Image Watermarks Are Provably Removable Using Generative AI

NeurIPS 2024poster

Invisible watermarks safeguard images' copyrights by embedding hidden messages only detectable by owners. They also prevent people from misusing images, especially those generated by AI models. We propose a family of regeneration attacks to remove these invisible watermarks. The proposed attack met…

2024

MarkLLM: An Open-Source Toolkit for LLM Watermarking

EMNLP 2024system demonstrations

Watermarking for Large Language Models (LLMs), which embeds imperceptible yet algorithmically detectable signals in model outputs to identify LLM-generated text, has become crucial in mitigating the potential misuse of LLMs. However, the abundance of LLM watermarking algorithms, their intricate mech…

2024

Monitoring AI-Modified Content at Scale: A Case Study on the Impact of ChatGPT on AI Conference Peer Reviews

ICML 2024oral

We present an approach for estimating the fraction of text in a large corpus which is likely to be substantially modified or produced by a large language model (LLM). Our maximum likelihood model leverages expert-written and AI-generated reference texts to accurately and efficiently examine real-wor…

2024

Pride and Prejudice: LLM Amplifies Self-Bias in Self-Refinement

ACL 2024long

Recent studies show that large language models (LLMs) improve their performance through self-feedback on certain tasks while degrade on others. We discovered that such a contrary is due to LLM’s bias in evaluating their own output. In this paper, we formally define LLM’s self-bias – the tendency to…

2024

Provable Robust Watermarking for AI-Generated Text

ICLR 2024poster

We study the problem of watermarking large language models (LLMs) generated text — one of the most promising approaches for addressing the safety challenges of LLM usage. In this paper, we propose a rigorous theoretical framework to quantify the effectiveness and robustness of LLM watermarks. We pro…

Cited by 166SourcePDFScholar
2023

Pre-trained Language Models Can be Fully Zero-Shot Learners

ACL 2023long

How can we extend a pre-trained model to many language understanding tasks, without labeled or additional unlabeled data? Pre-trained language models (PLMs) have been effective for a wide range of NLP tasks. However, existing approaches either require fine-tuning on downstream labeled datasets or ma…

2022

Compressing Sentence Representation for Semantic Retrieval via Homomorphic Projective Distillation

ACL 2022findings

How to learn highly compact yet effective sentence representation? Pre-trained language models have been effective in many NLP tasks. However, these models are often huge and produce large sentence embeddings. Moreover, there is a big performance gap between large and small models. In this paper, we…