2025/07/23 Created
*The contents of this page will be valid for the new server (csgs3). The start date of the new server has not yet been decided. The current server (csgs2) will be available until at least August 24th.
Private Key (id_ed25519): Must be protected with a passphrase and never shared.
Public Key (id_ed25519.pub): Safe to share. Please give it to the server administrator for registration from UTOL.
Open Windows Terminal. You can search it with word "terminal" from start menu.
Run the following command:
ssh-keygen -t ed25519
Answer the prompts:
File location (press Enter to accept default. C:\users\USERNAME\.ssh\id_ed25519 is private key file. C:\users\USERNAME\.ssh\id_ed25519.pub is public key file.)
Passphrase (set a secure passphrase to protect your private key)
After your public key is registered on the server, connect using:
ssh xxxxxxxxxx@csgs3.e..u-toko.ac.jp
*xxxxxxxxxx is your common ID(10 digits).
On first connection, you’ll see:
The authenticity of host 'csgs3.e.u-tokyo.ac.jp (xxx.xxx.xxx.xxx)' can't be established.
ED25519 key fingerprint is SHA256:xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.
Are you sure you want to continue connecting (yes/no/[fingerprint])?
→ Type yes to add the host to your known_hosts file. You won’t be asked again next time.
Open Terminal.
Run the following command:
ssh-keygen -t ed25519
Answer the prompts:
File location (press Enter to accept default. ~/.ssh/id_ed25519 is private key file. ~/.ssh/id_ed25519.pub is public key file.)
Passphrase (set a secure passphrase to protect your private key)
After your public key is registered, connect using:
ssh username@csgs3.e.u-tokyo.ac.jp
On first connection, you’ll see:
The authenticity of host 'csgs3.e.u-tokyo.ac.jp (xxx.xxx.xxx.xxx)' can't be established.
ED25519 key fingerprint is SHA256:xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.
Are you sure you want to continue connecting (yes/no/[fingerprint])?
→ Type yes to add the host to your known_hosts file. You won’t be prompted again.
If you have any questions, please contact the csgs2 manager (Email: csgs-info [at] e.u-tokyo.ac.jp).