arXiv AI

PrivacyGuard: Source-Linked Sanitization and Locally Resolvable PII References for Cloud GUI Agents

arXiv Computer Vision
Sep 14

BodhiPromptShield: Pre-Inference Prompt Mediation for Surface-Form Privacy Propagation in LLM Agent Pipelines

BodhiPromptShield is a policy‑aware mediation layer for LLM agent pipelines that detects sensitive text spans before they propagate, replacing them with typed placeholders, semantic abstractions, or secure tokens and restoring them only at authorized execution boundaries. In evaluations on AI4Privacy, PrivacyLens, and AgentDojo datasets, the system reduces identifier exposure to 7.4% and 1.8% respectively, and limits exact identifier leakage in final actions to 2.1–3.1%. While mediation preserves factual content according to automated metrics, human annotations show a significant drop in inferability from 100% to 24–53%, indicating the need for human validation of semantic‑leakage measures.

By Bo Ma, Jinsong Wu, Weiqi Yan
arXiv AI
Oct 26

MCPHunt: An Evaluation Framework for Cross-Boundary Data Propagation in Multi-Server MCP Agents

MCPHunt is a benchmark framework that isolates non‑adversarial credential propagation across multi‑server MCP trust boundaries. It uses canary‑based taint tracking, a controlled coverage design with risky, benign, and hard‑negative conditions, and completion‑requires‑secret stratification to separate faithful from policy‑violating propagation. Across 3,615 traces from 5 models, policy‑violating propagation rates range from 11.5 % to 41.3 %, with mitigation via prompting reducing rates to 0.3 % while retaining 80.5 % utility.

By Haonan Li, Tianjun Sun, Yongqing Wang, Qisheng Zhang
arXiv AI
Oct 31

Judging Before Propagation: Task-Graph Contextual Integrity for Multi-Agent Privacy

The paper introduces Task-Graph Contextual Integrity (TG‑CI), a formalism that extends traditional Contextual Integrity to multi‑agent systems by modeling workflows as Multi‑Agent Task Graphs (MATGs). TG‑CI evaluates privacy not just at individual disclosures but across the entire downstream propagation, offering two enforcement policies—Full‑Scope and Auto‑Region—that balance privacy protection with task performance. A new benchmark, MAPLE‑Bench, demonstrates that TG‑CI can cut unauthorized disclosures by up to 94% while preserving over 94% of task accuracy compared to existing local‑history CI methods.

By Hengyu Wu, Blaise Delattre, Yang Cao
arXiv Machine Learning
5d ago

PrivacyFlow: Privacy in AI Agents through Information Flow Analysis and Consequence-Aware Risk Management

PrivacyFlow introduces a new benchmark, PrivacyBench, and a defense system that separates privacy planning from task execution in autonomous LLM agents. The system traces data provenance, models recipient knowledge, and simulates inference attacks to weigh disclosure risk against task utility, allowing it to minimize or block data sharing. Experiments show that PrivacyFlow reduces privacy failures and increases completed task sequences by 22–55 percentage points, while revealing a tradeoff between privacy, utility, and user autonomy.

By Robin Staab, Tom Wollschl\"ager, Vahab Mirrokni, Reza Shokri
arXiv AI
2d ago

Signed, Sealed, Leaked: Trust Beyond Signature for MCP Toolchains

The paper exposes a vulnerability in AI toolchains where signed Model Context Protocol (MCP) tools can hide malicious code that leaks data, even when protected by state‑of‑the‑art runtime defenses. It introduces germline execution, which runs each tool invocation in an isolated, data‑free copy, limiting information disclosure to only what is authorized for the destination. Experiments on 153 attack runs show that germline execution prevents unauthorized disclosure in all cases, outperforming baseline defenses and ablations, while maintaining efficient performance (10‑49 ms per invocation).

By Yichiet Aun (Universiti Tunku Abdul Rahman), Mohammed A. Alhartomi (University of Tabuk), Jing Jie Tan (National University of Singapore), Waqas Nadeem (Universiti Tunku Abdul Rahman), Adeb Salh (Universiti Tunku Abdul Rahman), Shankar Karuppayah (Bitranger, CYRES, Universiti Sains Malaysia), Sin Chee Tan (ABLEs)