Description
Extended Triple DH[1], the key-exchange of the Signal protocol, it depends on XEDDSA since it uses the peers long-term identity keys to both sign and DH in this protocol.
The Double Ratchet[2] also part of the Signal protocol, this derives keys at every send/receiving of messages, providing self-healing and forward secrecy.
i guess i also have to add the footnotes from table 10, to the attributes of the double ratchet secret key attribute table. but i'm a bit unsure about all this.
[1] https://signal.org/docs/specifications/x3dh/
[2] https://signal.org/docs/specifications/doubleratchet/