Tor is one of the most popular darknets, which is known for its high levels of anonymity. Even though Tor’s protocol and its relay security have been thoroughly studied, there is currently no detailed analysis of the framework and privacy of hidden web services on this widely used darknet.
To address this, a group of researchers formulated a specialized analysis platform that they used to crawl and analyze more than 1.5 million URLs of hidden web services hosted on 7257 onion domains. For each studied web page, its resources, backlinks and its redirection graphs were thoroughly analyzed, along with the category and language distribution. As per the experiments done by the researchers, Tor hidden web services are grouped within a sparse, yet highly connected graph, throughout which approximately 10% of all onion sites are technically completely isolated.
As connections between various web pages represent an innate feature of the surface web, websites on the dark web are more isolated and ephemeral. Accordingly, crawling the dark web represents a rather daunting task.
Results of the Comprehensive Privacy Analysis:
For the first time in literature, this study measures the tight connection that is present between Tor’s hidden web services and websites of the surface web. More specifically, over 20% of the onion domains analyzed throughout the study, imported resources from websites on the surface web. Moreover, backlinks to websites on the surface web, were much more prevalent than backlinks to onion domains.