arXiv Computation and Language

SecJev: Bringing Security Expertise to System One Decision Models

SecJev is a family of Jev-like decision models specialized for security, ranging from 0.8 B to 9 B parameters. Built on Kev’s single‑pass candidate scorer, it learns Boolean, choice, and ordered decisions from text, telemetry, and observation histories, and is trained on the SecJev‑Corpus that unifies source‑label prediction and explicit‑policy evaluation across 14 tasks and eight sources. The security specialization improves every model, with SecJev‑0.8B outperforming general Kev‑9B by 20.51 percentage points in task‑macro accuracy and matching generative fine‑tuning in accuracy and latency while using less peak inference memory.

arXiv AI
Sep 17

MiST: Mid-Training LLMs for Cybersecurity

MiST (Mid-trained Security Transformer) is a suite of 8B and 32B language models tailored for cybersecurity, achieving strong performance on public benchmarks. The approach uses a mid-training stage that adapts general pre-trained models to the domain by curating a compact, expert-vetted seed corpus and generating high-quality synthetic training data, rather than continual pre-training on large raw text. MiST checkpoints improve mean cybersecurity accuracy by +13.1 and +8.6 absolute percentage points over Qwen baselines for 8B and 32B models, respectively, and provide a stronger initialization for downstream task-specific fine-tuning and reinforcement learning.

By Oded Ovadia, Elad Ben Zaken, Elad Guttman, Orly Moreno Kadosh
arXiv Machine Learning
Oct 3

Benchmarking System One decision models against trained classifiers and language models for automated decision gates

The paper evaluates System One decision models—typed models that output probabilities for branching decisions—against supervised classifiers and generative language models on automated decision gate tasks. Eight checkpoints from six families, including the hosted model Jev, were benchmarked on workflow, intent, and social‑science items, showing that small trained classifiers match or slightly outperform decision models on intent and workflow when labels are available, while decision models outperform zero‑shot classifiers when labels are absent. The study also explores calibration, risk thresholds, and cost‑efficiency trade‑offs, providing condition‑dependent design guidelines for automated decision gates.

By Amir Rafe, Subasish Das
arXiv AI
2d ago

Lev-3B: A Data Recipe for Compact Probabilistic Log Decision Models

Lev‑3B is a 3‑billion‑parameter decision model built on Granite‑4.1‑3B‑Base that uses a two‑stage training recipe. First, it learns bounded natural‑language decisions without log data, then it trains on logs while mixing target tasks with 35 unrelated auxiliary log tasks. The shared checkpoint performs better on unseen sources than training on logs alone, and outperforms prompted frontier models on anomaly detection at lower serving cost, though it lags on attack‑technique classification and shows calibration issues on excluded logging systems.

By Leo Betthauser, Yingqi Liu, Uday Shah, Jishang Wei, Sainyam Galhotra, Liang Gou, Vedant Dharnidharka, Hao Yang
arXiv Machine Learning
Jul 31

Cybersecurity Detection Classification with Reasoning-enabled Language Models

arXiv:2607. 28460v1 Announce Type: new Abstract: A major issue in Security Operations Centers (SOCs) is alert fatigue, as the number of detections reported is more than staff can triage in a given day.

By Amol Khanna, Manu Nandan, Cristian Viorel Popa, Joan Pujol-Roig, Diana Bolocan, Laura Vasilie, Alexandru Apostu, Chase Helwig, Mihaela Gaman, Michael Brautbar, Edward Raff, Chase Midler, Sven Krasser
arXiv AI
Jul 2

Toward Cybersecurity-Expert Small Language Models

arXiv:2510. 14113v2 Announce Type: replace-cross Abstract: Large language models (LLMs) are transforming everyday applications, yet deployment in cybersecurity lags due to a lack of high-quality, domain-specific models and training datasets.

By Matan Levi, Daniel Ohayon, Ariel Blobstein, Ravid Sagi, Ian Molloy, Yair Allouche