Visualization of bitcoin transactions for forensic and security analysis

Abstract

“Time for PlanB” – the increasing dissatisfaction with centralized currencies and the enormous increase in value caused the cryptocurrency Bitcoin to gain in importance over the last few years. Bitcoin is a peer-to-peer system with a publicly available decentralized database, the so-called “Blockchain”, where all transactions are stored. The main goal of this thesis is to explore a new way to visualize this transaction information in an interactive form. Our visualization gives a better understanding of the (pseudo-)anonymity and security of Bitcoin and enables analysts to get insight into past and current transactions. A special emphasis is placed on the time component to better understand chronological correlations. This helps forensic and security analysts to understand cash flows. The prototype presented in this thesis (PlanB) combines visualization techniques, clustering algorithms and statistical probabilities to provide exact information. PlanB is a web-based application to extract security-related visual feedback of the Blockchain. To ensure a smooth interaction with the data, a GPGPU method implemented by Matthias Gusenbauer is used to load the information constantly in the background. Further, this thesis evaluates the prototype, highlights strengths and weaknesses and describes future work.