arXiv AI

Backdoor Sentinel: Detecting and Detoxifying Backdoors in Diffusion Models via Temporal Noise Consistency

Backdoor Sentinel introduces Temporal Noise Consistency (TNC), a new phenomenon where backdoor activation disrupts noise prediction consistency across adjacent diffusion timesteps, while clean inputs remain stable. Leveraging TNC, the authors propose TNC-Defense, a closed‑loop gray‑box framework that includes TNC‑Detect for auditors to identify and localize anomalous timesteps without accessing model weights, and TNC‑Detox for service providers to perform trigger‑agnostic, timestep‑aware corrections that suppress backdoor behavior. Experiments on five backdoor attacks show an 11% improvement in detection accuracy and a 98.5% invalidation rate of triggered samples with minimal impact on generation quality.

arXiv Machine Learning
Jun 3

Backdooring Masked Diffusion Language Models

arXiv:2605. 19262v2 Announce Type: replace Abstract: Masked diffusion language models (MDLMs) are emerging as a compelling new paradigm for text generation, but their training-time security remains largely unexplored.

By Daniel Yiming Cao, Chengzhong Wang, Sheng-Yen Chou, Chengyu Huang, Pin-Yu Chen, Shengwei An
Hugging Face Trending Papers
Jul 29

ToxScreen: Detecting Whether an LLM Has Been Poisoned

As large language models (LLMs) are deployed in high-stakes domains, adversaries may poison training data to implant backdoors: hidden triggers that covertly manipulate model behavior at inference time. We ask whether a defender can recover such a trigger under realistic affordances, namely white-box access to the weights and knowledge of the behavior of concern, but no training data, no trusted reference model, no knowledge of the trigger, and no certainty that the model is poisoned.

arXiv Machine Learning
Jul 30

ToxScreen: Detecting Whether an LLM Has Been Poisoned

arXiv:2607. 26849v1 Announce Type: cross Abstract: As large language models (LLMs) are deployed in high-stakes domains, adversaries may poison training data to implant backdoors: hidden triggers that covertly manipulate model behavior at inference time.

By Anthony Hughes, Nicole Xing, Collin Francel, Andy Kim, Andrew Draganov
Hugging Face Trending Papers
Jul 7

Two Sides of the Same Coin: Learning the Backdoor to Remove the Backdoor

The community has recently developed various training-time defenses to counter neural backdoors introduced through data poisoning. In light of the observation that a model learns poisonous samples responsible for the backdoor easier than benign samples, these approaches either use a fixed threshold of the training loss for splitting or iteratively learn a reference model as an oracle for identifying benign samples.