Who Are the Money Launderers? Money Laundering Detection on Blockchain via Mutual Learning-Based Graph Neural Network

With the development of blockchain technology, security concerns have become increasingly prominent in recent years. Money laundering through blockchain has been found to generate a significant amount of money and has become a serious threat. Towards money laundering detection in Bitcoin, conventional methods heavily rely on fixed expert rules, leading to low accuracy and poor scalability. Graph convolutional network approaches have improved this issue, but they fail to distinguish the importance of surrounding transactions and the structural information of different transactions. To solve above problems, we propose an approach to detect money laundering on blockchain by mining its transaction records, named AEtransGAT. First, we use a novel approach called transGAT as an encoder to determine the significance of surrounding transactions by considering the transaction amount values of transaction flows. The original features and the features after graph embedding are combined to address the issue of feature distortion. Second, we deploy the graph autoencoder as the decoder to learn the overall structural information of different transactions, and the concatenated embedding is used to output the classification results as the detector. Finally, we propose our model based on mutual learning in this task which takes the advantages of both transactions classification loss and structure reconstruction loss. We validate the performance of our model on the Elliptic dataset which is the only large open source dataset in Bitcoin anti-money laundering. The results show that our method outperforms current state-of-the-art methods and is linearly scalable.