wkrp
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10 months ago This paper was presented at FOCI 2023. There's a PDF and an HTML version. There should be a presentation video at some point, but not yet.
Running a high-performance pluggable transports Tor bridge David Fifield, Linus Nordberg https://www.petsymposium.org/foci/2023/foci-2023-0011.php https://www.bamsoftware.com/papers/pt-bridge-hiperf/
The pluggable transports model in Tor separates the concerns of anonymity and circumvention by running circumvention code in a separate process, which exchanges information with the main Tor process over local interprocess communication. This model leads to problems with scaling, especially for transports, like meek and Snowflake, whose blocking resistance does not rely on there being numerous, independently administered bridges, but which rather forward all traffic to one or a few centralized bridges. We identify what bottlenecks arise as a bridge scales from 500 to 10,000 simultaneous users, and then from 10,000 to 50,000, and show ways of overcoming them, based on our experience running a Snowflake bridge. The key idea is running multiple Tor processes in parallel on the bridge host, with externally synchronized identity keys.
Linus Nordberg and I are preparing a short paper for submission to the next FOCI. It's about a special way of running a Tor bridge, running multiple copies of the tor process to permit better scaling—kind of an extended version of what is posted at #103 and the Snowflake bridge installation guide.
I am posting the draft here to see if there are any comments before we submit. Our deadline is 2023-03-15.
pt-bridge-hiperf.20230307.pdf