Evaluating Onion Address Collection Methods

This work investigates and evaluates multiple methods of collecting Tor onion addresses to be used in further research.
Some of those methods have been used frequently in the past, while others have not been used in research so far.
The resulting dataset represents the largest known collection of unique v3 onion addresses with a total of 482.614 unique entries.
In order to verify the existence of the collected addresses, several hidden service directory nodes were deployed to harvest blinded public keys.
Correlating these keys with the collected onion addresses reveals how many of the discovered onion addresses were active, how much usage they received and what fraction of overall onions they represent.
The collected onion addresses were used to unblind more than 25\% of the collected blinded public keys which were responsible for 66\% of all successful service descriptor downloads.