SSH & Login

To access any ACCESS resource you'll need an SSH client and a public/private key pair. This page covers connecting via SSH, generating keys, and registering them with your target resources.

Logging In via SSH

Watch Video: SSH Videos

Connect to any ACCESS resource using a standard SSH client. Your login node hostname is listed on each resource's documentation page.

# General form
$ ssh username@login.resource.access-ci.org

# Example: Expanse at SDSC
$ ssh jsmith123@login.expanse.sdsc.edu

SSH key authentication recommended

Many resources require or strongly recommend SSH key-based authentication. Generate a key pair on your local machine and upload the public key through your ACCESS account settings.

SSH Key Registry to share SSH public keys across resources

Managing SSH Keys

SSH uses a public/private key pair for secure authentication. Your public key can be shared freely with any resource you log in to. Your private key must stay securely stored on your computer and never be shared.

Before logging in to an ACCESS resource for the first time, complete two steps:

  1. Generate a key pair on your computer
  2. Upload your public key to the Resource Providers you use

You only need to do this once per computer. If you work from multiple machines, repeat both steps on each one.

Generating SSH Keys

On Linux, macOS, Windows PowerShell, or WSL, run ssh-keygen in a terminal. The ed25519 algorithm is recommended for ACCESS users:

$ ssh-keygen -t ed25519

Accept the default filename. Enter a strong passphrase you can remember. Your keys are saved in ~/.ssh/ — id_ed25519 (private) and id_ed25519.pub (public).

On Windows, graphical SSH clients can also generate keys:

  • Bitvise — SSH terminal and file transfer. Client Key Manager → Generate New → Ed25519
  • MobaXterm — includes an X-server for remote GUI apps. Tools → MobaKeyGen → EdDSA
  • PuTTY — lightweight terminal. Run puttygen → EdDSA → Generate

Uploading Your Public SSH Key

Upload your public key (id_ed25519.pub) to each RP you plan to use. Resource Providers support several approaches:

  1. Via the RP's ACCESS OnDemand server — log in with your ACCESS ID, open a browser terminal, and paste your public key into ~/.ssh/authorized_keys
  2. Via the ACCESS ID Management system — upload at account.access-ci.org; ACCESS stores the key and RPs pull it when activating your account
  3. Via the RP's web portal (ACCESS ID) — some RPs have their own portal where you log in with ACCESS credentials and upload your key
  4. Via the RP's web portal (RP ID) — some RPs issue a separate RP-specific login for their key upload service
  5. Via email — a small number of RPs ask you to email your public key to their support team

The ACCESS SSH Key Registry lets you register one public key and share it across multiple resources. Register at operations.access-ci.org