collaborators

5 papers

cs.CR2026

Your Privacy Depends on Others: Collusion Vulnerabilities in Individual Differential Privacy

Johannes Kaiser, Alexander Ziller, Eleni Triantafillou +2

Individual Differential Privacy (iDP) promises users control over their privacy, but this promise can be broken in practice. We reveal a previously overlooked vulnerability in samp…

cs.LG2025

From Mean to Extreme: Formal Differential Privacy Bounds on the Success of Real-World Data Reconstruction Attacks

Anneliese Riess, Kristian Schwethelm, Johannes Kaiser +4

The gold standard for privacy in machine learning, Differential Privacy (DP), is often interpreted through its guarantees against membership inference. However, translating DP budg…

cs.LG2025

Laplace Sample Information: Data Informativeness Through a Bayesian Lens

Johannes Kaiser, Kristian Schwethelm, Daniel Rueckert +1

Accurately estimating the informativeness of individual samples in a dataset is an important objective in deep learning, as it can guide sample selection, which can improve model e…

cs.LG2025

Visual Privacy Auditing with Diffusion Models

Kristian Schwethelm, Johannes Kaiser, Moritz Knolle +3

Data reconstruction attacks on machine learning models pose a substantial threat to privacy, potentially leaking sensitive information. Although defending against such attacks usin…

cs.LG2025

Differentially Private Active Learning: Balancing Effective Data Selection and Privacy

Kristian Schwethelm, Johannes Kaiser, Jonas Kuntzer +3

Active learning (AL) is a widely used technique for optimizing data labeling in machine learning by iteratively selecting, labeling, and training on the most informative data. Howe…