Scope

This report mainly focuses on

• problems with deploying ECH and how to adress these,
• sources of misconfigurations
• implications of deploying ECH (assessing subsequent risks)
• attacks against ECH enabled servers
• possibilities for censorship or denial of service
• the interface layers between protocols which play together to make ECH possible

None-scope

The report does NOT try to

• analyse if the used cryptographic libraries, primitives or algorithms are safe (or quantum resistant)
• prove the security of individual implementations (or the lack of, by breaking or analysing concrete implementations)