Deanonymization of bitcoin cryptocurrency users

The aim of this article is to show how one can deanonymize users of cryptocurrencies. To this end the most popular of the cryptocurrencies, i.e. bitcoin is used as an example. At the beginning, the basic concepts about cryptocurrencies are presented. Afterwards, our approach to systematize the types of transactions existing in the blockchain is proposed. This part is enriched with the graphs showing their quantitative occurrence in the blockchain. The main part of this article presents the heuristics use to deanonymize users. A few practical pieces of advice for implementation of the presented heuristics in the real deanonymizing system are included. Then the real case studies are introduced. They are supported with comments based on the experience from court trials carried out by the authors. The final part contains legal regulations and existing tools supporting the deanonymizing process. Keywords: deanonymization, cryptocurrency, bitcoin.