The National Institute for Computational Sciences

Access and Login

Current NICS Resources

ResourceOTP LoginGSISSHGridFTP
  • In case of a system outage, can always be used to access user's home directories on NFS.
  • Secure Access With OTP

    The preferred method of secure access to NICS resources is through SSH with an RSA One Time Password (OTP) token. As part of the NICS account activation procedure, you will receive information about obtaining an RSA token. Tokens are sent by US mail and are not enabled until NICS receives the notarized Token Activation Form.

    RSA Keyfob

    Logging in with OTP requires using a personal pin number plus the current code displayed on the OTP token—this combination is referred to as your NICS passcode. Along with your token, you will receive instructions on setting up your pin number for the first time. Use SSH along with your NICS passcode to log in to NICS resources, for example:

> ssh <username>

Note: No characters will appear when entering passcode.

Accounts that are not used for a period of three consecutive months are disabled. If you believe your account has been disabled for inactivity please submit a request to or you may call the helpline directly at 865-241-1504.

About SSH

UNIX-based operating systems generally have an SSH client built in and Windows users may obtain free clients online, such as PuTTY.

Any SSH client used to log into NICS resources should:

  • Support the SSH-2 protocol (supported by all modern SSH clients). Several security vulnerabilities exist in the SSH-1 protocol, therefore, access using a version 1 client is not allowed.
  • Allow keyboard-interactive authentication to access NICS systems. For UNIX-based SSH clients, the following line should be in either the default ssh_config file or your  $HOME/.ssh/config file:
    PreferredAuthentications keyboard-interactive,password
    The line may also contain other authentication methods, so long as keyboard-interactive is included. For recent versions of SecureCRT or PuTTY, the setting can be made through the SSH connection properties menu.

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Other Login Issues

RSA Key Fingerprints

Occasionally, you may receive an error message upon logging in to a system such as the following:

Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that the OTP host key has just been changed.

This can be a result of normal system maintenance that changes an RSA public key or could be an actual security incident. If these fingerprints do not match what your SSH/SCP/SFTP client shows you, do not continue authentication; instead, contact

X11 Forwarding

There are graphical tools you might want to use on NICS resources, which require using X11 forwarding. For example, there are a number of graphical debugging, optimization, as well as visualization tools that you might want to use. For instructions on setting up the X11 forwarding please see Procedures for X11 forwarding.

Changing Default Shell

You may change your default shell, by logging into the NICS User portal. After logging in to the portal, you may change your shell in the 'Login Information' section.

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