Acceleration of Anomaly Detection in Blockchain Using In-GPU Cache

Abstract

Blockchain is a distributed ledger system composed of a P2P network and is used for a wide range of applications, such as international remittance, inter-individual transactions, and asset conservation. In Blockchain systems, tamper resistance is enhanced by the property of transaction that cannot be changed or deleted by everyone including the creator of the transaction. However, this property also becomes a problem that unintended transaction created by miss operation or secret key theft cannot be corrected later. Due to this problem, once an illegal transaction such as theft occurs, the damage will expand. To suppress the damage, we need countermeasures, such as detecting illegal transaction at high speed and correcting the transaction before approval. However, abnormality detection in the Blockchain at high speed is computationally heavy, because we need to repeat the detection process using various feature quantities and the feature extractions become overhead. In this paper, to accelerate abnormality detection, we propose to cache transaction information necessary for extracting feature in GPU device memory and perform both feature extraction and abnormality detection in the GPU. We employ abnormality detection using K-means algorithm based on the conditional features. When the number of users is one million and the number of transactions is 100 millions, our proposed method achieves 37.1 times faster than CPU processing method and 16.1 times faster than GPU processing method that does not perform feature extraction on the GPU.