You have a set up ssh keys to access all URI HPC clusters. This issue usually pops up if your keys are not set up correctly.
You must generate an ssh key and send the public half ( never send the private key) to hpc@etal.uri.edu when you first sign up. With the command line ssh, you should also have a command called ssh-keygen to create a key if you do not already have one ( When prompted, press Enter to use the default file name ). Please set a passphrase on this key. You will be prompted for this passphrase when you connect. This will generate two files: the private key ~/.ssh/id_rsa and the public key ~/.ssh/id_rsa.pub. Only send the id_rsa.pub file in the email. If you are using putty, you can use the Putty Key Generator (puttygen) utility to generate the ssh2 key (email only the text in the box at the top beginning with ssh-rsa). You can then either use the Putty Agent (pageant) to store the key, or configure it directly in Putty under Connections/SSH/Auth/Private Key file.
NOTE: On MacOS you can either use the command cat ~/.ssh/id_rsa.pub | pbcopy to copy the contents to the clipboard, or attach the file. You may need to use ⌘-Shift-Period to toggle being able to see files/directories starting with a “.”.