An Analysis of Anonymity in the Bitcoin System
Anonymity is not a prominent design goal of Bitcoin. However, Bitcoin is often referred to as being anonymous. We have performed a passive analysis of anonymity in the Bitcoin system using publicly available data and tools from network analysis. The results show that the actions of many users are far from anonymous. We note that several centralized services, e.g. exchanges, mixers and wallet services, have access to even more information should they wish to piece together users' activity. We also point out that an active analysis, using say marked Bitcoins and collaborating users, could reveal even more details.
The technical details are contained in a preprint on arXiv. We welcome any feedback or corrections regarding the paper. To illustrate our findings, we have chosen a case study involving a user who has many reasons to stay anonymous. He is the alleged thief of 25,000 Bitcoins. This is a summary of the victim's postings to the Bitcoin forums and an analysis of the relevant transactions.
