Semisol on Nostr: Post-compromise security refers to recovery from a total leakage of internal state. ...
Post-compromise security refers to recovery from a total leakage of internal state.
The DH ratchet uses continuous key exchanges to update itself in a non deterministic way.
In your case, this is not actually a DH ratchet, but a symmetric ratchet without any data mixed in (the root) being used to feed the sender and receiver ratchets. This makes the system state determinstic and gets rid of post-compromise guarantees, and has equivalent security guarantees as using a single ratchet for send and one for receive.
I also do not see how the “active participant changing” would be defined in contexts where there’s concurrent events being sent.
The DH ratchet uses continuous key exchanges to update itself in a non deterministic way.
In your case, this is not actually a DH ratchet, but a symmetric ratchet without any data mixed in (the root) being used to feed the sender and receiver ratchets. This makes the system state determinstic and gets rid of post-compromise guarantees, and has equivalent security guarantees as using a single ratchet for send and one for receive.
I also do not see how the “active participant changing” would be defined in contexts where there’s concurrent events being sent.