Throughout 2020 and 2021, the Tor anonymity network has undergone significant changes, with the Tor software team releasing new versions of its software that update the way .onion domains look and work.
More specifically, the Tor Project has done away with the 16-character-long .onion domain, also known as a v2 address, and replaced it with a 56-character-long domain, known as v3. The most obvious difference between the v2 and v3 onion services is the different address formats. v3 onion addresses have 56 characters instead of 16 (because they contain the full ed25519 public key, not just the hash of the public key), which means that migrating from v2 to v3 requires all users to learn/remember/save the new onion addresses.
This move is intended to improve the privacy, security, and resilience of the Tor network against anonymization attacks, a move announced several years in advance and a process that took over a year to complete: the
September 2020-The Tor Project releases v0.4.4 of the Tor anonymization software, warning server operators that v2 domains are about to be phased out.
July 2020-Tor developers release Tor v0.4.6, which prevents server owners from registering v2 onion domains.
October 2021 - All Tor branches release stable versions, removing support for v2 domains.
November 2021 - The Tor Project releases Tor Browser 11, which removes support for v2 domains.
But despite the Tor team's best efforts to announce the move ahead of time, new data compiled and released by DarkOwl, a dark web monitoring company, shows that the Tor network still consists of a large percentage of servers running the old v2 domains.
"Over the past six weeks, DarkOwl's Vision platform has observed a total of 104,095 active .onion services in both address schemes, of which: 62 percent are v2 addresses and 38 percent are v3 addresses." The company said.
DarkOwl said it detected a spike in new v3 domains in July 2021, which coincided with the Tor team adding a full-screen warning before accessing v2 domains in preparation for the browser's v11 release this fall.
This resulted in over 2,900 v3 domains being registered in the last two weeks of July alone. As the Tor team noted in its own v2 to v3 analysis in September, the number of v3 domains is trending upward.
Currently, new v2 domains can no longer be registered on the Tor network, and users can only access existing sites using older versions of the Tor browser, but old v2 domains can still be loaded.
However, while the number of v3 sites is still below 50%, everyone expects v2 sites to disappear completely within the next year. The reason for this is that since most Tor node operators will update their servers to versions that do not support v2 domains, there will be no Tor relays capable of routing traffic to these older domains in the future.