DeletedUser88 Do you know if both Work Profile and Private Space have separate encryption keys
Private space has separate encryption key and separate weaver slot just like secondary users, as long as you select to use separate credentials when setting up the private space.
For work profiles, it is the device management app that creates the work profile that decides. It can choose to not have any credentials at all if it wants.
DeletedUser88 but cannot communicate with them through IPC.
If the device admin app that created the work profile allows app to communicate cross-profile, they can communicate cross-profile.
Private space prevents all such cross-profile communication. Except for telephony, as @Carlos-Anso described.