Read the link I provided. Apple documents the security mechanisms of how a lot of their services work. Universal Clipboard (and handoff) does not use iMessage.
I've read a lot of their whitepapery security stuff but my understanding and differentiation of terms like "Continuity", "Handoff", "Universal ______", "Airplay" vs "Screen Mirroring" etc needs revision and reconsolidation.
Read the link I provided. Apple documents the security mechanisms of how a lot of their services work. Universal Clipboard (and handoff) does not use iMessage.
You may find additional things documented here:
https://support.apple.com/guide/security/welcome/web
This whole area of their support site is well worth the read if you are concerned about security and privacy.
I've read a lot of their whitepapery security stuff but my understanding and differentiation of terms like "Continuity", "Handoff", "Universal ______", "Airplay" vs "Screen Mirroring" etc needs revision and reconsolidation.