benw8888 / stegllm

StegLLM

Large Language Models and Beyond Class Project

Our goal is to understand whether language models will learn to hide information in plain sight given reward pressure in a reinforcement learning environment.

Abstract:

Steganography, the art of conveying a secret message while concealing its existence in plain sight, is a capability that would be concerning to see in language models. Language models capable of steganography would be able to communicate and plan without our supervision, posing a safety concern. Therefore, we investigate to what extent current language models can perform steganography in an end-to-end reinforcement learning setting. We compare the performance of LLaMA (Touvron et al., 2023), a language model with 6 billion parameters, with GPT-2 (small) (Radford et al., 2018), a 124 million parameter model. We train the models in a multi-agent setting using Proximal Policy Optimization (Schulman et al., 2017), a popular reinforcement learning technique, and employ optimizations for training large language models including ZeRO (Rajbhandari et al., 2020) and LoRA (Hu et al., 2021). We show that while GPT-2 (small) fails at the steganography task, LLaMA is able to succesfully en- code and decode secret messages, although the steganography scheme employed is limited in complexity. Our work lays the foundation for steganographic capability evaluations for future language models and paints a concerning trend regarding our ability to supervise scaled up models.