Texas A&M University

Keith Crabb

Ph.D. Student, Computer Science & Engineering Graduate Researcher, Texas A&M Cybersecurity Center

I study how AI systems fail under attack, and how to measure those failures honestly. My current work red-teams the defenses placed in front of large language models: prompt-injection detectors, and the LLM judges they hand uncertain inputs to. I also study how far LLM judges and the uncertainty signals in retrieval-augmented generation can be trusted. Before that I worked on industrial control system security, building digital-twin testbeds for intrusion-detection research and machine-learning detectors for threats in operational-technology networks.

I am advised by Dr. J. A. “Drew” Hamilton at the Texas A&M Cybersecurity Center.

Portrait of Keith Crabb

Research

Most of my current work is on the security and evaluation of LLM systems. It grew out of earlier work on cyber-physical systems, where the question was also how a detector holds up once an adversary knows it is there.

01

Adversarial Evaluation of LLM Defenses

Prompt-injection defenses are usually evaluated against attacks that were never aimed at them. I build the defenses and then attack them with white-box gradient search, black-box query search, and paraphrase attacks. The target is not only the detector but the whole pipeline around it, including the gates that decide when an expensive LLM judge is consulted.

FAT-CHUD

02

Reliability of LLM Evaluation

LLM judges and uncertainty scores are increasingly the instruments that other results are measured with. I study when those instruments can be trusted: how judges behave when the evidence is buried in ordinary text, and whether disagreement among retrieved sources predicts a wrong answer in retrieval-augmented generation. That work runs on frozen protocols, paired controls, and blinded human review.

03

Cyber-Physical & Space Systems

Attack traffic cannot be injected into a running plant, so I built digital-twin software that reproduces SCADA networks faithfully enough to test intrusion detection on. I have evaluated learned and similarity-based detectors for advanced persistent threats in industrial control networks, and contributed to a post-quantum protocol for satellite links that must also survive radiation-induced faults.

[C1] [C2] [C3] [C4]

Publications

Peer-reviewed conference papers. A current list is also on Google Scholar.

2026

  • [C4]

    RRPQ-SCP: Radiation-Resilient Post-Quantum Satellite Communication Protocol

    E. Johnson, K. Crabb, J. Leiden, D. Hamilton

    AIAA AVIATION 2026 Forum · 2026

  • [C3]

    Evaluation of GBDTs in APT Identification Tasks within ICS Networks

    K. A. Crabb II, E. Johnson IV, J. A. Hamilton Jr.

    Advances in Computer Science Applications and Research (Springer) · 2026 · pp. 158–170

2025

  • [C2]

    Development of a Digital Twin Software for SCADA Focused Anomaly and Intrusion Detection Systems Research

    K. A. Crabb, H. Coleman, D. Hamilton

    39th ACM SIGSIM Conference on Principles of Advanced Discrete Simulation (SIGSIM-PADS) · 2025 · pp. 83–87

2024

  • [C1]

    Anomaly Detection in ICS Networks with Fuzzy Hashing

    W. Tatum, N. Gariani, K. A. Crabb, G. De Conto, J. A. Hamilton

    2024 Cyber Awareness and Research Symposium (CARS) · 2024 · pp. 1–5

Software

Research code and tooling. Code for papers in preparation is released alongside them.

Teaching

Notes

Occasional writing on methodology, tooling, and results that do not belong in a paper: negative results, testbed notes, and reproducibility details.

All notes

Contact

Email
lampsdad@tamu.edu
Affiliation
Texas A&M Cybersecurity Center
Department of Computer Science & Engineering
Texas A&M University, College Station, TX
Elsewhere
Google Scholar
GitHub
X / Twitter (@KCrabbII)