Using SSH on an iMac running Lion
Solution 1:
Easiest way in this case is to just
- create another user using the Preferences panel
- log into this user locally
- generate the appropriate SSH key pair
- transfer the public key to your friend over a secure channel
In addition you may want to tighten up your system a bit by preventing SSH logins without keys. Open /etc/sshd_config in any text editor and set
PasswordAuthentication no
PermitEmptyPasswords no
Afterwards restart SSH by disabling and enabling remote login in Preferences.