Journal of Current Research in Blockchain
Vol. 3 No. 2 (2026): Regular Issue June 2026

Anomaly Detection in Blockchain Transactions Using Isolation Forest and Autoencoder Deep Learning Models

Heru Supriyanto (Magister of Computer Sciences, Amikom Purwokerto University, Indonesia)
Murtiyoso (Magister of Computer Sciences, Amikom Purwokerto University, Indonesia)
Nilasari (Magister of Computer Sciences, Amikom Purwokerto University, Indonesia)



Article Info

Publish Date
25 May 2026

Abstract

Blockchain technology enables decentralized and transparent digital transactions, yet its open architecture also increases vulnerability to fraudulent and irregular activities. This study evaluates the effectiveness of the Isolation Forest method for detecting anomalous patterns within blockchain transaction data. A simulated dataset consisting of 10,130 transactions was constructed, including 62 injected anomalies that represent realistic irregular behaviours such as unusually large transaction values, extreme gas price spikes, and rapid consecutive transfers by a single sender. After applying feature engineering to capture temporal frequency, transaction dynamics, sender and receiver behaviour, and gas-related attributes, the Isolation Forest model was trained and evaluated using the embedded anomaly labels. The model achieved a precision of 0.4516, a recall of 0.4516, and an F1 score of 0.4516, indicating moderate detection capability. Analysis of the confusion matrix and anomaly score distribution further revealed overlapping characteristics between rare but legitimate transactions and true anomalies, which contributed to misclassification. Overall, the findings suggest that Isolation Forest can serve as an early anomaly filtering mechanism, although additional contextual information or hybrid detection strategies are needed to enhance performance in real blockchain environments.

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Journal Info

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Journal

Publisher

Subject

Computer Science & IT Decision Sciences, Operations Research & Management Economics, Econometrics & Finance

Description

The Journal of Current Research in Blockchain publishes high-quality research on: Blockchain technology Smart Contract Data Privacy Decentralization Data Distributed Ledger Technology Decentralized Applications Our goal is to provide a platform for researchers, practitioners, and policymakers to ...