Tor Browser's default bridges

Tor Browser ships with a number of default bridges. These bridges are hard-coded in the file bridge_prefs.js. The following table is meant to be an authoritative list of our default bridges plus the people who operate these bridges. Whenever we add, remove, or change any of our default bridges, make sure to commit this change to the following repositories:

Also, use the tbb-bridges trac keyword for new tickets related to default bridges.

Type IP:port Fingerprint Parameters Contact URL Status
obfs4 C8CBDB2464FC9804A69531437BCF2BE31FDD2EE4 cert=Hmyfd2ev46gGY7NoVxA9ngrPF2zCZtzskRTzoWXbxNkzeVnGFPWmrTtILRyqCTjHR+s9dg iat-mode=1 Sina Rabbani <srabbani@…> Mailing list
obfs4 0BAC39417268B96B9F514E7F63FA6FBA1A788955 cert=VwEFpk9F/UN9JED7XpG1XOjm/O8ZCXK80oPecgWnNDZDv5pdkhq1OpbAH0wNqOT6H6BmRQ iat-mode=1 Sina Rabbani <srabbani@…> Mailing list
obfs4 CDF2E852BF539B82BD10E27E9115A31734E378C2 cert=qUVQ0srL1JI/vO6V6m/24anYXiJD3QP2HgzUKQtQ7GRqqUvs7P+tG43RtAqdhLOALP7DJQ iat-mode=1 David Goulet <dgoulet@…> #22429 Metrics
obfs4 88CD36D45A35271963EF82E511C8827A24730913 cert=eGXYfWODcgqIdPJ+rRupg4GGvVGfh25FWaIXZkit206OSngsp7GAIiGIXOJJROMxEqFKJg iat-mode=1 Mart van Santen <mart@…> #22468 Metrics
obfs4 D9A82D2F9C2F65A18407B1D2B764F130847F8B5D cert=bjRaMrr1BRiAW8IE9U5z27fQaYgOhX1UCmOpg2pFpoMvo6ZgQMzLsaTzzQNTlm7hNcb+Sg iat-mode=0 Mart van Santen <mart@…> #22468 Metrics
obfs4 011F2599C0E9B27EE74B353155E244813763C3E5 cert=ayq0XzCwhpdysn5o0EyDUbmSOx3X/oTEbzDMvczHOdBJKlvIdHHLJGkZARtT4dcBFArPPg iat-mode=0 Felix <zwiebel@…> #23166 Metrics
obfs4 91A6354697E6B02A386312F68D82CF86824D3606 cert=PBwr+S8JTVZo6MPdHnkTwXJPILWADLqfMGoVvhZClMq/Urndyd42BwX9YFJHZnBB3H0XCw iat-mode=0 Felix <zwiebel@…> #23166 Metrics
obfs4 0DB8799466902192B6C7576D58D4F7F714EC87C1 cert=XPUwcQPxEXExHfJYX58gZXN7mYpos7VNAHbkgERNFg+FCVNzuYo1Wp+uMscl3aR9hO2DRQ iat-mode=0 Noisebridge #24756 Metrics
obfs4 FB70B257C162BF1038CA669D568D76F5B7F0BABB cert=vYIV5MgrghGQvZPIi1tJwnzorMgqgmlKaB77Y3Z9Q/v94wZBOAXkW+fdx4aSxLVnKO+xNw iat-mode=0 Louis-Philippe Véronneau <pollo@…> #28185 Metrics
obfs4 2D82C2E354D531A68469ADF7F878FA6060C6BACA cert=4TLQPJrTSaDffMK7Nbao6LC7G9OW/NHkUwIdjLSS3KYf0Nv4/nQiiI8dY2TcsQx01NniOg iat-mode=0 Tobias Pulls <tobias.pulls@…> #31164 Metrics
obfs4 86AC7B8D430DAC4117E9F42C9EAED18133863AAF cert=0LDeJH4JzMDtkJJrFphJCiPqKx7loozKN7VNfuukMGfHO0Z8OGdzHVkhVAOfo1mUdv9cMg iat-mode=0 Tobias Pulls <tobias.pulls@…> #31164 Metrics
obfs4 1AE2C08904527FEA90C4C4F8C1083EA59FBC6FAF cert=ItvYZzW5tn6v3G4UnQa6Qz04Npro6e81AP70YujmK/KXwDFPTs3aHXcHp4n8Vt6w/bv8cA iat-mode=0 Tobias Pulls <tobias.pulls@…> #31164 Metrics
obfs4 74FAD13168806246602538555B5521A0383A1875 cert=ssH+9rP8dG2NLDN2XuFw63hIO/9MNNinLmxQDpVa+7kTOa9/m+tGWT1SmSYpQ9uTBGa6Hw iat-mode=0 Micah Sherr <msherr@…> #32606 Metrics
meek 97700DFE9F483596DDA6264C4D7DF7641E1E39CE url= Sina Rabbani <srabbani@…> #21342 Metrics
snowflake 2B280B23E1107BB62ABFC40DDCC8824814F80A72 N/A David Fifield <david@…> N/A Metrics

Adding new default bridges

The following is an informal list of requirements that we have for default bridges:

  • A reliable network link that can handle at least a sustained 100 Mbit/s of traffic.
    • Any modern CPU can sustain at least 100 MBit/s. A CPU with the AES-NI extension is particularly helpful because it allows Tor to offload its AES operations to the CPU.
    • We recommend 4 GB of RAM for 100 MBit/s.
    • For more than 100 MBit/s, a second core may be necessary and more than 4 GB of RAM.
  • We would like to personally know you (or somebody who is involved in the bridge's operation).
    • You should also have a sustainable plan for running the bridge, so it doesn't get abandoned.
  • It's useful (but not necessary) for the bridge to have a dedicated IP address because this IP address will get blocked by China and other places.
    • If you don't have a dedicated IP address, don't host any services on the bridge that you don't want to see blocked in some countries or networks.
  • You shouldn't also be running an exit relay.
  • You should give us at least a one month notice before they shut down their bridge.

Tickets related to default bridges

Ticket Summary Status Owner Keywords Priority
#13727 BridgeDB should not distribute Tor Browser's default bridges assigned bridgedb-dist, tbb-bridges, anti-censorship-roadmap-september, s30-o23a1 Medium
#18113 Dynamically allocate clients to default Tor Browser bridges of a certain type needs_information brade tbb-bridges Medium
#29275 Get default bridges checked for reachability by OONI new tbb-bridges, ex-sponsor-19 Medium
#29277 Look into getting default Tor bridges scanned by external reachability tests assigned phw augur, measurement, anti-censorship-roadmap-november, s30-o21a1, tbb-bridges Medium
#30121 Create authoritative, parseable list of Tor Browser's default bridges assigned phw tbb-bridges Medium
#30794 Create lightweight censorship analyser for users assigned phw tbb-bridges Medium
#31523 Recruit potential default bridges from set of long-running bridges new tbb-bridges Medium
#32547 Set up default bridge at the University of Minnesota assigned phw tbb-bridges Medium

Last modified 11 days ago Last modified on Dec 2, 2019, 4:51:29 PM