Add user "Joe":
# adduser --gecos "" joe
Allow Joe execute administrative commands (with root priveleges):
# usermod -a -G sudo joe
Allow Joe connect remotelly:
# usermod -a -G ssh-clients joe
Use PUTTYGEN.EXE to generate public and private keys. Protect private key with password. Put the private key to the folder with sensitive data. Copy the content of the "Public key for pasting into OpenSSH authorized_keys file:" field and create authorized_keys on the server as follows:
# su joe $ cd ~ $ mkdir .ssh $ chmod 700 .ssh $ vi .ssh/authorized_keys ... paste copied public key ... $ chmod 600 .ssh/*
Run PAGEANT.EXE and add the private key. Create shortcut for pageant.exe with the private key parameter. You can add it into the Startup program group in the Start menu to start pageant automatically.
Test the connection by creating new session with putty. Set "Auto-login user name" to "joe" and put the path to the private key into the "Private key file for authentication" field.