FlowTransformer: A Transformer Framework for Flow-based Network Intrusion Detection Systems

Abstract

This paper presents the FlowTransformer framework, a novel approach for implementing transformer-based Network Intrusion Detection Systems (NIDSs). FlowTransformer leverages the strengths of transformer models in identifying the long-term behaviour and characteristics of networks, which are often overlooked by most existing NIDSs. By capturing these complex patterns in network traffic, FlowTransformer offers a flexible and efficient tool for researchers and practitioners in the cybersecurity community who are seeking to implement NIDSs using transformer-based models. FlowTransformer allows the direct substitution of various transformer components, including the input encoding, transformer, classification head, and the evaluation of these across any flow-based network dataset. To demonstrate the effectiveness and efficiency of the FlowTransformer framework, we utilise it to provide an extensive evaluation of various common transformer architectures, such as GPT 2.0 and BERT, on three commonly used public NIDS benchmark datasets. We provide results for accuracy, model size and speed. A key finding of our evaluation is that the choice of classification head has the most significant impact on the model performance. Surprisingly, Global Average Pooling, which is commonly used in text classification, performs very poorly in the context of NIDS. In addition, we show that model size can be reduced by over 50\%, and inference and training times improved, with no loss of accuracy, by making specific choices of input encoding and classification head instead of other commonly used alternatives.

References in corpus (7)

• Graph Transformer Networks
• A survey of dimensionality reduction techniques
• TabTransformer: Tabular Data Modeling Using Contextual Embeddings
• DI-NIDS: Domain Invariant Network Intrusion Detection System
• On Generalisability of Machine Learning-based Network Intrusion Detection Systems
• Flow-based Network Intrusion Detection Based on BERT Masked Language Model
• Group Generalized Mean Pooling for Vision Transformer

Cited by in corpus (5)

• Transformers and Large Language Models for Efficient Intrusion Detection Systems: A Comprehensive Survey
• Towards Explainable Network Intrusion Detection using Large Language Models
• Optimized detection of cyber-attacks on IoT networks via hybrid deep learning models
• Mapping the Landscape of Generative AI in Network Monitoring and Management
• Moderating New Waves of Online Hate with Chain-of-Thought Reasoning in Large Language Models