Isn’t “_perfect_” forward secrecy a misnomer in this context? One of the big innovations of the signal protocol, (called axolotl at the time) was that perfect

Isn’t “_perfect_” forward secrecy a misnomer in this context? One of the big innovations of the signal protocol, (called axolotl at the time) was that perfect forward secrecy, requires a handshake between participants before _each_ message, which is not compatible with the nature of async messaging, where the recipient might be (probably is) offline at the time of sending. Instead Signal protocol does an eventual key ratcheting as soon as messages are round tripped between participants by essentially attaching half a handshake to each outgoing message.