Can I have encryption without authentication or authentication without encryption?
Yes, authentication and encryption on a Canopy system are inter-related, but can be separately enabled and disabled. That is, an operator can enable/disable authentication and encryption independently for a PtP link or a PtMP set of links.
Encryption protects the link, but doesn't ensure who you are linked to.
Authentication ensures you are linked to a module with the user-specified or factory-installed authentication key, but doesn't protect the link.