papers

Publications (13)

cs.CR2025

Detecting Benchmark Contamination Through Watermarking

Tom Sander, Pierre Fernandez, Saeed Mahloujifar +2

Benchmark contamination poses a significant challenge to the reliability of Large Language Models (LLMs) evaluations, as it is difficult to assert whether a model has been trained…

cs.CR2026

How Good is Post-Hoc Watermarking With Language Model Rephrasing?

Pierre Fernandez, Tom Sander, Hady Elsahar +6

Generation-time text watermarking embeds statistical signals into text for traceability of AI-generated content. We explore *post-hoc watermarking* where an LLM rewrites existing t…

cs.CV2025

Pixel Seal: Adversarial-only training for invisible image and video watermarking

Tomáš Souček, Pierre Fernandez, Hady Elsahar +5

Invisible watermarking is essential for tracing the provenance of digital content. However, training state-of-the-art models remains notoriously difficult, with current approaches…

cs.CV2025

Watermark Anything with Localized Messages

Tom Sander, Pierre Fernandez, Alain Durmus +2

Image watermarking methods are not tailored to handle small watermarked areas. This restricts applications in real-world scenarios where parts of the image may come from different…

cs.CV2026

Learning to Watermark in the Latent Space of Generative Models

Sylvestre-Alvise Rebuffi, Tuan Tran, Valeriu Lacatusu +6

Existing approaches for watermarking AI-generated images often rely on post-hoc methods applied in pixel space, introducing computational overhead and potential visual artifacts. I…

stat.ML2024

Implicit Bias in Noisy-SGD: With Applications to Differentially Private Training

Tom Sander, Maxime Sylvestre, Alain Durmus

Training Deep Neural Networks (DNNs) with small batches using Stochastic Gradient Descent (SGD) yields superior test performance compared to larger batches. The specific noise stru…

cs.CR2024

Watermarking Makes Language Models Radioactive

Tom Sander, Pierre Fernandez, Alain Durmus +2

We investigate the radioactivity of text generated by large language models (LLM), i.e. whether it is possible to detect that such synthetic input was used to train a subsequent LL…

cs.CV2024

Differentially Private Representation Learning via Image Captioning

Tom Sander, Yaodong Yu, Maziar Sanjabi +4

Differentially private (DP) machine learning is considered the gold-standard solution for training a model from sensitive data while still preserving privacy. However, a major barr…

cs.LG2023

TAN Without a Burn: Scaling Laws of DP-SGD

Tom Sander, Pierre Stock, Alexandre Sablayrolles

Differentially Private methods for training Deep Neural Networks (DNNs) have progressed recently, in particular with the use of massive batches and aggregated data augmentations fo…

cs.CV2025

The Moon's Many Faces: A Single Unified Transformer for Multimodal Lunar Reconstruction

Tom Sander, Moritz Tenthoff, Kay Wohlfarth +1

Multimodal learning is an emerging research topic across multiple disciplines but has rarely been applied to planetary science. In this contribution, we propose a single, unified t…

cs.CR2026

TextSeal: A Localized LLM Watermark for Provenance & Distillation Protection

Tom Sander, Hongyan Chang, Tomáš Souček +10

We introduce TextSeal, a state-of-the-art watermark for large language models. Building on Gumbel-max sampling, TextSeal introduces dual-key generation to restore output diversity,…

cs.AI2024

Log-normal Mutations and their Use in Detecting Surreptitious Fake Images

Ismail Labiad, Thomas Bäck, Pierre Fernandez +5

In many cases, adversarial attacks are based on specialized algorithms specifically dedicated to attacking automatic image classifiers. These algorithms perform well, thanks to an…

cs.CL2026

Verifiably grounded machine interpretation of lunar geology

Tom Sander, Kay Wohlfarth, Christian Wöhler

Planetary geology relies on historical, interpretive reasoning to reconstruct past events from diverse observations. Here, we present a step toward an automated "machine intelligen…