he wanted a solution that doesn't require authentication.
If you absolutely have to do this, look at rsh http://linux.die.net/man/1/rsh
using /etc/hosts.equiv http://linux.die.net/man/5/hosts.equiv
or same syntax inside a user's home dir in a file called '.rhosts' eg https://akamal.wordpress.com/2007/01...-remote-shell/
Absolutely INSIST on getting this in writing, because when it's cracked, you will be the fall guy if you haven't CYA'd
Actually, ssh+suth keys would be transparent/invisible to the user once you've set it up; that still sounds like the best idea to me.
Have you got a reason from your mgr why he thinks he doesn't want auth?