Filename: 235-kill-named-flag.txt
Title: Stop assigning (and eventually supporting) the Named flag
Authors: Sebastian Hahn
Created: 10 April 2014
Implemented-In: 0.2.6, 0.2.7
Status: Closed
1. Intro and motivation
Currently, Tor supports the concept of linking a Tor relay's nickname
to its identity key. This happens automatically as a new relay joins
the network with a unique nickname, and keeps it for a while. To
indicate that a nickname is linked to the presented identity, the
directory authorities vote on a Named flag for all relays where they
have such a link. Not all directory authorities are currently doing
this - in fact, there are only two, gabelmoo and tor26.
For a long time, we've been telling everyone to not rely on relay
nicknames, even if the Named flag is assigned. This has two reasons:
First off, it adds another trust requirement on the directory
authorities, and secondly naming may change over time as relays go
offline for substantial amounts of time.
Now that a significant portion of the network is required to rotate
their identity keys, few relays will keep their Named flag. We should
use this chance to stop assigning Named flags.
2. Design
None so far, but we should review older-but-still-supported Tor
versions (down to 0.2.2.x) for potential issues. In theory, Tor
clients already support consensuses without Named flags, and testing
in private Tor networks has never revealed any issues in this regard,
but we're unsure if there might be some functionality that isn't
typically tested with private networks and could get broken now.
3. Implementation
The gabelmoo and tor26 directory authorities can simply remove the
NamingAuthoritativeDirectory configuration option to stop giving out
Named flags. This will mean the consensus won't include Named and
Unnamed flags any longer. The code collecting naming statistics is
independent of Tor, so it can run a while longer to ensure Naming can
be switched on if unforeseen issues arise.
Once this has been shown to not cause any issues, support for the
Named flag can be removed from the Tor client implementation, and
support for the NamingAuthoritativeDirectory can be removed from the
Tor directory authority implementation.
4. Open questions
None.