The following seems to be a common problem, but I have not found anything to resolve the problem in my case. I have 2 laptops ARTHUR and GALAHAD. ARTHUR is running ubuntu 16.04 (32 bit), GALAHAD is running ubuntu 18.04. I can SSH from GALAHAD to ARTHUR from a shell with no problems using Public Keys. If I try to connect to ARTHUR from GALAHAD using Remmina (via VNC) it works OK if I use password authentication in the SSH tunnelling, but this is not very secure. If I try to use Public key (automatic), after entering the SSH private key passphrase I get this message:
ssh automatic public key authentication failed: failed to read key: /home/stuart/.ssh/authorized_keys
If instead I try to use 'identity file' and select '~/.ssh/authorized_keys' I get the following message:
SSH public key authentication failed: Access denied.
I think this is not an SSH issue because I can connect using SSH from a shell, I think this is a Remmina issue. Any guidance would be much appreciated.