Measurement action bounds

We determine a set of action bounds to use during our Tor measurements. As described by Jansen and Johnson [0], these describe the maximum amount of network activity that our privacy techniques will protect (i.e. the amount of activity to which our differential privacy guarantee will apply). These bounds apply to users of the Tor network, which include both Tor clients and onion services.

1. Exit-circuit domains

2. Loading webpage (intermediate action)

3. Exit data

4. IP Addresses

5. TCP connections

6. Entry circuits

7. Entry data

8a. Descriptor upload (v2)

8b. Descriptor upload (v3 - unused)

8c. Unique-address descriptor upload

9a. Descriptor lookup (v2)

9b. Descriptor lookup (v3 - unused)

9c. Unique-address descriptor lookup

10. Introduction Point (IP) connections

11. Rendezvous Point (RP) connection

12. Rendezvous data

[0] Rob Jansen and Aaron Johnson, "Safely Measuring Tor", ACM CCS 2016.