arXiv Machine Learning

Decorrelation Is Not Complementarity: Skill, Not Lineage, Governs Trusted-Monitor Ensembles

arXiv:2608. 16190v1 Announce Type: cross Abstract: Trusted monitoring has a cheap, trusted model score a stronger untrusted model's actions, and a diverse ensemble of them beats a single stronger monitor at matched cost.

arXiv Machine Learning
Sep 14

A False Average: Pooled CoT-Monitor Accuracy Conceals a Reasoning-Dependent Fragility

The paper demonstrates that aggregate accuracy figures for chain‑of‑thought (CoT) monitors can be misleading because a large portion of detected hacks rely solely on action patterns rather than reasoning. By rewriting only the agent’s reasoning to appear truthful while keeping actions identical, the authors show that the monitor’s performance on the reasoning‑dependent subset collapses dramatically, yet the overall pooled accuracy drops only modestly. The study reveals that CoT monitors are fragile when reasoning is the key signal and that accuracy should be reported separately for this subset.

By Shikhar Shiromani, Leo Richter
arXiv Machine Learning
Sep 22

A Shared Learning Rate Is Not a Neutral Control in Selective On-Policy Distillation

The paper investigates selective on‑policy distillation, where a student model is trained only on token positions chosen by a selector. It demonstrates that the commonly used shared learning rate is not neutral: performance varies significantly with the learning rate for different selectors, leading to inconsistent comparisons. The authors attribute this selector‑rate entanglement to the selection process itself and recommend reporting the full arm‑by‑rate matrix for fair evaluation.

By Chencheng Zhu
arXiv AI
Sep 10

Protocol effects on feature-based hardware-Trojan detection across Trust-Hub families

The study evaluates how the choice of test boundary affects feature‑based hardware Trojan detection across Trust‑Hub families. Using a corpus of 49,124 gates from 16 netlists, the authors compare three test settings—pooled gates, a single netlist held out, and an entire host family held out—showing that performance drops markedly when a host family is excluded. The results demonstrate that sibling benchmark variants can inflate detection metrics, and the authors recommend reporting family‑aware holdouts alongside pooled scores.

By Hang Xiao, Chuhong Xu, Kainan Zhou, Gangzhen Qian, Lu Yi
arXiv Computation and Language
Aug 31

Layered LLM Defenses as an Ensemble: Access Tiers, Inference Cost, and the Measured Failure Correlation Between Defense Layers

The paper investigates whether stacking multiple defenses around large language models (LLMs) truly compounds security. Using the Adversary Access‑Tier Model (AATM) and a cost‑tiering system, the authors analyze a seven‑layer defense stack and find that failure correlations between layers are consistently positive, meaning the residual attack success is higher than the multiplicative prediction. Despite high coverage and low false refusals, the stack’s performance is largely driven by common architectural causes rather than diverse, independent defenses.

By Abrar Alotaibi, Muhammad Shahid Jabbar, Sadam Al-Azani, Moataz Ahmed
arXiv AI
Aug 24

JuryProbe: An Empirical Consensus-Risk Diagnostic for Routing Reference-Free Factuality Judge Panels to Grounded Verification

JuryProbe is an empirical diagnostic tool designed to assess consensus risk in panels of reference‑free large language model judges used for factuality verification. It estimates risk by measuring false‑negative correlations and false‑consensus lift from a labeled calibration probe, and routes high‑risk majority decisions to judges with trusted references. The approach was validated on FEVER corruptions, showing that flagged decisions can be grounded without additional reference acquisition in most cases, while reducing false accepts by about 0.4% and avoiding 28% of reference acquisitions.

By Tianxin Zhou, Ruixi Lin