collaborators

5 papers

cs.CL2026

Where Does Authorship Signal Emerge in Encoder-Based Language Models?

Francis Kulumba, Guillaume Vimont, Laurent Romary +1

Authorship attribution models fine-tuned with the same pretrained encoder, data, and loss can differ four-fold in performance depending only on their scoring mechanism. We use mech…

cs.CL2026

Language-Switching Triggers Take a Latent Detour Through Language Models

Francis Kulumba, Wissam Antoun, Théo Lasnier +2

Backdoor attacks on language models pose a growing security concern, yet the internal mechanisms by which a trigger sequence hijacks model computations remain poorly understood. We…

cs.DL2026

HALvest-Contrastive: Retrieval-Like Authorship Attribution with Patch-Level Late Interaction

Francis Kulumba, Wissam Antoun, Guillaume Vimont +2

Authorship attribution asks whether two pieces of text share a writer, but topical confound makes the task deceptively easy: two authors covering the same topic may look more alike…

cs.CL2026

Language Triggers Hijack Language Circuits: A Mechanistic Analysis of Backdoor Behaviors in Large Language Models

Théo Lasnier, Wissam Antoun, Francis Kulumba +2

Backdoor attacks pose significant security risks for Large Language Models (LLMs), yet the internal mechanisms by which triggers operate remain poorly understood. We present the fi…

cs.CL2024

CamemBERT 2.0: A Smarter French Language Model Aged to Perfection

Wissam Antoun, Francis Kulumba, Rian Touchent +3

French language models, such as CamemBERT, have been widely adopted across industries for natural language processing (NLP) tasks, with models like CamemBERT seeing over 4 million…