Neural ranking models underpin many modern search applications, including retrieval-augmented generation systems, but remain surprisingly susceptible to carefully crafted, subtle alterations to text. Jiawei Liu, Zhuo Chen, and Rui Zhu, along with colleagues from Wuhan University and Yale University, now demonstrate a new defence against these ‘adversarial attacks’ that manipulate search results. Their work introduces RobustMask, a technique that combines the predictive power of large language models with a randomised masking process to smooth out the effects of malicious changes. The team provides a mathematical guarantee that RobustMask protects the top-ranked search results, and experiments show it successfully certifies robustness for over 20% of candidate documents even when up to 30% of their content is perturbed, representing a significant advance in securing these increasingly important systems against manipulation.
Conference Trends and Model Identifiers
This analysis identifies key trends within a collection of research data, focusing on years, conference abbreviations, and model identifiers. The conferences most frequently cited include NIPS, Security, and SP. Specific models mentioned trace an evolution from GloVe and BERT to RoBERTa and other transformer-based architectures, highlighting advancements in natural language processing. The data also includes numerical values related to statistical models, such as 2-poisson, and page numbers from conference proceedings. Observations reveal a significant increase in research concerning adversarial attacks and defenses in NLP from 2019 onwards, peaking in 2020 and continuing through 2024. CIKM and EMNLP consistently appear as prominent venues for research in this field, indicating their importance to the community.
RobustMask Defends Ranking Models From Attacks
The study introduces RobustMask, a novel defense against adversarial attacks targeting neural ranking models, increasingly used in applications like retrieval-augmented generation. Researchers addressed the vulnerability of these models to subtle text manipulations by combining the predictive power of pre-trained language models with a randomized masking strategy, strengthening ranking models against perturbations at multiple levels. This approach ensures more reliable search results and system integrity. RobustMask smooths the ranking model through random masking, creating variations of input documents where portions of the text are temporarily hidden.
Robust Ranking with Randomized Text Masking
Scientists have developed RobustMask, a new defense mechanism that significantly enhances the adversarial robustness of neural ranking models, crucial components in modern search engines and retrieval-augmented generation systems. The research addresses a critical vulnerability where subtle alterations to text can manipulate search results and compromise system integrity. Unlike existing defenses, RobustMask combines the context-prediction abilities of pretrained language models with a randomized masking technique. The core of RobustMask strategically masks portions of the input text, creating a smoothed ranking model resilient to perturbations.
Experiments demonstrate that RobustMask successfully certifies over 20% of candidate documents within the top-10 ranking positions, even when subjected to adversarial attacks affecting up to 30% of their content. This certification provides a theoretical guarantee of stability, ensuring consistent top-K predictions despite malicious manipulations. The team achieved this by leveraging the pairwise comparison capabilities of ranking models and applying probabilistic statistical analysis to formally prove certified top-K robustness. This breakthrough delivers a practical and theoretically sound solution for safeguarding information retrieval systems against increasingly sophisticated attacks, prioritizing the most relevant information for users.
Certified Robustness for Neural Ranking Models
This research presents RobustMask, a new defense against adversarial attacks on neural ranking models used in information retrieval. The team successfully combines the predictive capabilities of established language models with a randomised masking technique, smoothing the model and making it more resilient to subtle, malicious alterations of text. The researchers provide a theoretical guarantee of ‘certified top-K robustness’, demonstrating the method can confidently protect the top ten ranked documents against content manipulation. Experiments confirm that RobustMask can certify the robustness of over 20% of candidate documents within the top ten results, even when up to 30% of their content is perturbed by adversarial attacks. This represents a substantial improvement over existing defenses, which often rely on less reliable methods. The team acknowledges that the accuracy of their certification relies on estimations, and future work could explore applications to other neural networks and methods for improving certification accuracy.
👉 More information
🗞 RobustMask: Certified Robustness against Adversarial Neural Ranking Attack via Randomized Masking
🧠 ArXiv: https://arxiv.org/abs/2512.23307
