KVM (keyboard-video-mouse) sharing is useful when using two computers at a single desk.
For a virtual KVM, Barrier is a good virtual option.
To enable SSL between server/client machines, run the following (for macOS, for others, see this Github issue).
$ cd /Users/<user>/Library/Application Support/barrier/SSL
$ openssl req -x509 -nodes -days 365 -subj /CN=Barrier -newkey rsa:4096 -keyout Barrier.pem -out Barrier.pem
$ # restart barrier application