TorDNS: A Novel Correlated Onion Address Generation Approach and Application

Abstract

The onion service is the most important mechanism of the Tor network which enables service providers to publish anonymously various TCP services, such as web services. To access the target onion services, clients first know the 56-byte onion addresses. However, randomly generated onion addresses are difficult to memorize and can be easily used by attackers to generate phishing sites with similar onion addresses. In this paper, we propose a correlated onion address generation approach which is capable of generating a unique onion address via a customized string and a root onion address. This approach enables the generated onion addresses to be computed by clients using a human-memorable string, resulting in easier access to onion services. Based on this approach, we design and implement a Tor Domain Name System (TorDNS) that allows different service providers to register anonymously and clients to access anonymous services quickly through human-memorable pseudo-onion addresses. TorDNS is compatible with existing onion service mechanism and does not introduce additional privacy and security issues. In addition, similarity detection of pseudo-onion addresses can effectively reduce the risk of phishing sites on the Tor network.