You have two machines on networks you don't know/control and no established identities/accounts. You want to pipe some data between them without setting up a more permanent network like ZeroTier with SSH or other access.
> Normally things like transit don’t have encryption because it occurs at a higher level.
OpenVPN, IPsec, nebula, ZeroTier, Hamachi, and many others would disagree.
Wireguard:
+ Can tunnel arbitrary IP traffic
~ Has stricter encryption, with full asymmetric keys (and optionally adding a symmetric key)
- requires permissions to load a kernel module and configure the network stack
Hyperbeam:
+ Only needs userland UDP sockets, not a kernel module
~ Derives its keys from a passphrase, so does not require transferring a full cryptographic key between devices
- is a single application-layer pipe, applicable in shell workflows but not transparently tunneling arbitrary applications