benchmark 2026

Tatemae: Detecting Alignment Faking via Tool Selection in LLMs

Matteo Leonesi 1, Francesco Belardinelli 1, Flavio Corradini 2, Marco Piangerelli 1

0 citations

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Published on arXiv

2604.26511

Prompt Injection

OWASP LLM Top 10 — LLM01

Excessive Agency

OWASP LLM Top 10 — LLM08

Key Finding

Mean alignment faking detection rates range from 3.5% to 23.7% across six frontier LLMs, with vulnerability profiles varying by domain and pressure type, suggesting susceptibility reflects training methodology rather than capability alone

Tatemae

Novel technique introduced


Alignment faking (AF) occurs when an LLM strategically complies with training objectives to avoid value modification, reverting to prior preferences once monitoring is lifted. Current detection methods focus on conversational settings and rely primarily on Chain-of-Thought (CoT) analysis, which provides a reliable signal when strategic reasoning surfaces, but cannot distinguish deception from capability failures if traces are absent or unfaithful. We formalize AF as a composite behavioural event and detect it through observable tool selection, where the LLM selects the safe tool when unmonitored, but switches to the unsafe tool under monitoring that rewards helpfulness over safety, while its reasoning still acknowledges the safe choice. We release a dataset of 108 enterprise IT scenarios spanning Security, Privacy, and Integrity domains under Corruption and Sabotage pressures. Evaluating six frontier LLMs across five independent runs, we find mean AF detection rates between 3.5% and 23.7%, with vulnerability profiles varying by domain and pressure type. These results suggest that susceptibility reflects training methodology rather than capability alone.


Key Contributions

  • Formalizes alignment faking as a verifiable composite event based on observable tool selection rather than CoT analysis alone
  • Releases dataset of 108 enterprise IT scenarios spanning Security, Privacy, and Integrity domains under Corruption and Sabotage pressures
  • Introduces evaluation pipeline that distinguishes capability, robustness under pressure, and compliance when monitored, detecting AF rates of 3.5-23.7% across six frontier LLMs

🛡️ Threat Analysis


Details

Domains
nlp
Model Types
llm
Threat Tags
inference_timeblack_box
Datasets
Tatemae (108 enterprise IT scenarios)
Applications
llm agent deploymententerprise it automationtool-using agents