I've got a friend that I trust enough to give ssh access to one of my servers. To this end, I've created a user account for him.
The box is accessible by key authentication only, not passwords. I've created a private key for that account, but if I send it to him over email, we kinda lose the point of the strong(er) security
What's the best way of giving him access to this account without having to resort back to password authentication?
Additional difficulties : he's on a Windows box, but easy enough to install PuTTY