sequence_diagram.txt

# Sequence diagram for the README
# To regenerate, use https://bramp.github.io/js-sequence-diagrams/

Title: Choir usage example

participant example.com as dest [color="red"]
participant User as user [color="blue"]
participant Recursive resolver as resolver
participant Metrics server as metrics [color="green"]

# DNS lookup
user->resolver: dns:example.com?
resolver->user: {IP of example.com}

# Connection attempt
user->dest: Connection attempt
dest-->>user: Connection reset [color="red"]

# Choir report
user->resolver: dns:rst.q.us.20200202.\nexample.com.metrics.example?
Note left of resolver: The resolver already knows\nthat the user accessed\nexample.com, so this\nquery does not disclose\nadditional sensitive\ninformation.
resolver->metrics: dns:rst.q.us.20200202.\nexample.com.metrics.example?
Note left of metrics: Report is recorded here.\nThe metrics server only\nobserves the resolver's\nIP address, not the user's. [color="green"]
metrics->resolver: NXDOMAIN
resolver->user: NXDOMAIN
Note left of user: Response is ignored [color="blue"]