[Tails-dev] new features coming in to be aware of

Hi Tails devs,

So the legacy tor daemon recently got two new features in alpha you should be
aware of, proof-of-work and conflux circuits:

- proof-of-work: Onion service providers will be able to opt-in to a
proof-of-work requirement for connecting clients as a ddos counter-measure.
Legacy clients which do not support this feature will not be able to connect to
onion services making use of it. This feature will be transparent to the user,
though in Tor Browser we may surface custom ui notifying the user if they failed
to complete the pow in-time (or other pow-specific errors). The details are
still tbd, but any error would be surfaced to applications via a custom SOCKS5
error code (similar to how the tor daemon notifies applications that client auth
is required to access an onion service)
- conflux circuits: the network team has developed a multiple-circuit selection
routing system whereby clients will open multiple circuits to an endpoint, and
divide traffic between the circuits to increase network performance. Any ux that
shows a user's circuit will need to be updated to account for this new conflux
circuit reality. For the initial stable release, conflux circuits will only work
with clearnet endpoints so onion services are unaffected. The browser team will
be working with ux on any required ui changes during the next release cycle, so
if Tails has an analogous thing outside of Tor Browser you can probably follow
our lead there.

These feature are expected to hit stable around the end of this summer (so in a
few months).

best,
-Richard