- Detecting and Understanding censorship
- Challenges: Coverage(ipv4 scan w/global ip_id), Continuity(augur), Ethics(use infra machines)
- Side channels techniques
- DNS Layer: Satellite (2017): institutional open resolvers
- TCP/IP Layer: Spooky (2014), Augur(2017): Global IP_ID routers
- Application Layer: Quack (2018), HyperQuack(2020): services that reflect data (echo, http, ...)
- Spooky: uses TCP/IP side channels to detect whether a client and server can communicate![[Screenshot 2022-12-12 at 11.16.14 PM.png]]
- Augur: Repeat runs and use Sequential Hypothesis Testing to gradually build confidence
- Investigating Commercial VPNs
- key challenge: rigor, scale, automation