Understanding the Usage of Anonymous Onion Services: Empirical Experiments to Study Criminal Activities in the Tor Network

Research output: Book/ReportDoctoral thesisCollection of Articles

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Technology is the new host of life, and with each passing year, developments in digitalization make it easier to destroy our understanding of authenticity. A man is more than his distorted shadow on Facebook wall. Another essential shadow dwells under anonymity.

The aim of this thesis is to understand the usage of onion services in the Tor anonymity network. To be more precise the aim is to discover and measure human activities on Tor and on anonymous onion websites. We establish novel facts in the anonymous online environment. We solve technical problems, such as web-crawling and scraping to gather data. We represent new findings on how onion services hide illegal activities. The results are merged with wider range of anonymous onion services usage.

We selected to cast light to the criminal dark side of the Tor network, mainly black marketplaces and hacking. This is a somewhat factitious selection from the wide range of Tor use. However, an archetype villain is found in nearly every story so naturally, for the sake of being interesting, we selected criminal phenomenon to study. To be clear, the Tor network is developed and utilised for legal online privacy and several other essential ways.

The first finding is that as the Tor network becomes more popular also illegal activities become wide spread. Tor and virtual currencies are already transforming drug trade. Anonymous high-class marketplaces are difficult for the law enforcement to interrupt.

On the other hand, now illegal activities are paradoxically more public than ever: everyone can access these onion sites and browse the product listings. The illegal trade is transparent to be followed. For example, by the means of web-crawling and scraping, we produced nearly real-time picture of the trade in Finland following one of the marketplaces on Tor. As a result, statistics shed light on substance consumption habits: the second study estimates that sales totalled over two million euros between Finnish buyers and sellers.

Due to the network’s anonymity and nature of illegal sales, reputation systems have replaced the rule of law: a buyer trusts the seller’s reputation because the law is not guaranteeing the delivery. The only available information is the seller’s reputation and capacity which were both associated with drug sales as we prove.

Finally, we will identify the limits of online anonymity ranging from technical limitations to operation security dangers. Technology is merely a communication channel and major criminal activities still happen in the physical world. For instance, a drug trade requires that the seller sends the products using post service to the buyer’s address. Before that the seller has acquired enormous amounts of illegal drugs. The buyer has to give away his address to the seller who could later be placed under arrest with a list of customers addresses. Furthermore, we show case by case how criminals reveal and leak their critical identity information. The law enforcement agencies are experienced to investigate all of these aspects even if the Tor network itself is secure.
Original languageEnglish
PublisherTampere University
Number of pages98
ISBN (Electronic)978-952-03-1091-2
ISBN (Print)978-952-03-1090-5
Publication statusPublished - 24 May 2019
Publication typeG5 Doctoral dissertation (articles)

Publication series

NameTampere University Dissertations
ISSN (Print)2489-9860
ISSN (Electronic)2490-0028


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