arXiv Machine Learning

CALLIOPE: Private Insights into AI Use, Without Embeddings

CALLIOPE is a new top‑down framework designed to uncover topic hierarchies in large unstructured datasets, such as LLM conversations, while ensuring differential privacy. Unlike conventional methods that depend on clustering vector embeddings, CALLIOPE directly employs LLM capabilities throughout its pipeline. Experiments show that CALLIOPE delivers higher utility than embedding‑based approaches, particularly in high‑privacy scenarios, and its outputs are evaluated using both standard clustering metrics and newly introduced utility metrics.

arXiv Machine Learning
Oct 16

SHIP: Structured and Hierarchical Insight with Privacy

The paper introduces SHIP, a method that generates differentially private insights from textual data by mapping queries to attributes, constructing a hierarchical hybrid taxonomy, and releasing a DP synthetic table for analysis. It treats these insights as reusable representations to answer analytical queries, enabling a common basis for utility assessment. Experiments show SHIP outperforms existing private insight baselines in QA performance and structured fidelity, while highlighting remaining challenges for structured representations.

By Kai Chen, Guisi Ni, Albert Cheu, Kassem Fawaz, Yuzheng Hu, Ryan McKenna, Peter Kairouz
arXiv Machine Learning
Sep 16

Differentially Private Semantic Plans for Aggregate Insight Generation

The paper introduces ‘DP-SPIN’, a trusted‑curator framework that generates differentially private semantic plans for aggregate insight generation. ‘DP-SPIN’ maps each record to a bounded sparse nonnegative vector over pre‑defined semantic concepts, sums these vectors into a semantic sketch, and releases a noisy plan containing admitted concepts and their masses. The framework provides user‑level privacy by clipping each user’s contribution and ensures that the final summary is differentially private through post‑processing, with guarantees established under both add/drop and replacement adjacency.

By Behrooz Razeghi
arXiv AI
Oct 16

Private Retrieval Augmented Generation via Random Projection

The paper introduces a lightweight privacy-preserving technique for Retrieval-Augmented Generation (RAG) systems that uses random projection to transform both datastore and query embeddings. This approach maintains semantic similarity for effective retrieval while significantly reducing the risk of data extraction attacks. Experiments across various RAG architectures and datasets demonstrate that the method outperforms prior differential privacy-based techniques in both retrieval and generation performance while offering comparable empirical privacy.

By Dixi Yao, Tahseen Rabbani, Tian Li
arXiv Machine Learning
Jul 23

Differentially Private Neural Network Training Under the Hidden State Assumption

arXiv:2407. 08233v3 Announce Type: replace Abstract: Current differentially private learning paradigms face a severe utility bottleneck: DP-SGD degrades performance through noise accumulation over training steps, while aggregation-based approaches such as PATE suffer from data inefficiency due to disjoint data partitioning.

By Ding Chen, Haochen Luo, Xiaofei Wang, Chen Liu