Tor-powered Decentralized DNS for Tor Onion Services

Tor onion services, also known as hidden services, are anonymous servers of unknown location and ownership that can be accessed through any Torenabled client. They have gained popularity over the years, but since their introduction in 2002 still suffer from major usability challenges primarily due to their cryptographically-generated non-memorable addresses. In response to this difficulty, in this work we introduce the Onion Name System (OnioNS), a privacy-enhanced decentralized name resolution service. OnioNS allows Tor users to reference an onion service by a meaningful globally-unique verifiable domain name chosen by the onion service administrator. We construct OnioNS as an optional backwards-compatible plugin for Tor, simplify our design and threat model by embedding OnioNS within the Tor network, and provide mechanisms for authenticated denial-of-existence with minimal networking costs. We introduce a lottery-like system to reduce the threat of land rushes and domain squatting. Finally, we provide a security analysis, integrate our software with the Tor Browser, and conduct performance tests of our prototype. DOI 10.1515/popets-2017-0003 Received 2016-05-31; revised 2016-09-01; accepted 2016-09-02.