collaborators

5 papers

cs.LG2026

Eigenvalue Calibration for Semantic Embeddings of Large Language Models

Sebastian G. Gruber, Nassim Walha, Francis Bach +1

Uncertainty quantification is central to the reliable deployment of large language models (LLMs), and eigenvalues of semantic embeddings have recently emerged as a key tool in stat…

cs.LG2026

From Entropy to Calibrated Uncertainty: Training Language Models to Reason About Uncertainty

Azza Jenane, Nassim Walha, Lukas Kuhn +1

Large Language Models (LLMs) that can express interpretable and calibrated uncertainty are crucial in high-stakes domains. While methods to compute uncertainty post-hoc exist, they…

cs.LG2025

Fine-Grained Uncertainty Decomposition in Large Language Models: A Spectral Approach

Nassim Walha, Sebastian G. Gruber, Thomas Decker +4

As Large Language Models (LLMs) are increasingly integrated in diverse applications, obtaining reliable measures of their predictive uncertainty has become critically important. A…

cs.CR2025

IncogniText: Privacy-enhancing Conditional Text Anonymization via LLM-based Private Attribute Randomization

Ahmed Frikha, Nassim Walha, Krishna Kanth Nakka +3

In this work, we address the problem of text anonymization where the goal is to prevent adversaries from correctly inferring private attributes of the author, while keeping the tex…

cs.CR2025

ObfuscaTune: Obfuscated Offsite Fine-tuning and Inference of Proprietary LLMs on Private Datasets

Ahmed Frikha, Nassim Walha, Ricardo Mendes +3

This work addresses the timely yet underexplored problem of performing inference and finetuning of a proprietary LLM owned by a model provider entity on the confidential/private da…