Information Technology Education Journal
Vol. 5, No. 3, August (2026)

XGBoost Hyperparameter Optimization Using Optuna TPE for Multiclass Classification of Intrusion Detection in Internet of Things Networks

Maulana Akmal Ibrahim (Universitas Negeri Semarang)
Subhan (Universitas Negeri Semarang)



Article Info

Publish Date
02 Aug 2026

Abstract

Purpose – The majority of research on intrusion detection systems (IDS) still uses outdated datasets that don't accurately reflect contemporary IoT threats, ignoring issues with class imbalance and effective hyperparameter tuning. Using the CICIoT2023 dataset, this work builds a machine learning-based intrusion detection pipeline that can classify 27 IoT attack classes in a multiclass environment. Design/Methods/Approach – The pipeline includes data preprocessing, Random Forest Feature Importance to select the top 20 features from 40 numerical features, MinMaxScaler normalization, SMOTE to handle class imbalance, and Optuna Tree-structured Parzen Estimator (TPE) to optimize XGBoost hyperparameters over 50 trials with three-fold stratified cross-validation. Findings – On 9,992 test samples, XGBoost optimized with Optuna outperformed default XGBoost (F1: 98.97%), Random Forest (F1: 98.98%), and KNN (F1: 94.81%), achieving 99.07% accuracy and F1-Score. With a Best Cross-Validation F1 of 99.88%, Optuna determined the ideal configuration. SMOTE was shown to have the most F1 contribution (0.27%) in the ablation study. Research Implications/Limitations – This study is constrained to a 50,000-sample subset from the full 46 million CICIoT2023 records and has not been validated on other IoT datasets. The pipeline was evaluated solely in a modeling environment and has not been deployed on physical IoT devices, meaning performance under actual hardware constraints remains to be verified. Originality/Value – This study proposes an integrated pipeline with a leakage-free final test set combining XGBoost, Optuna TPE, Random Forest Importance-based feature selection, and SMOTE on CICIoT2023, contributing a potentially more computationally efficient IDS alternative compared to deep learning architectures with multiclass classification across 27 contemporary IoT attack types.

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Journal Info

Abbrev

INTEC

Publisher

Subject

Computer Science & IT Education

Description

INTEC Journal is published by the Informatics and Computer Engineering Education Study Program at Makassar State University. INTEC Journal is published periodically three times a year, containing articles on research results and / or critical studies in the field of Informatics and Computer ...