SSH keys enable secure authentication to an SSH or SFTP service.
Generating a private/public key under Windows
Get the latest version of PuttyGen on your computer via the official website :
(click on Download Putty to go to https://www.chiark.greenend.org.uk/~sgtatham/putty/latest.html, then find "puttygen.exe" to download)
Check that "RSA" 2048 is selected, or for a shorter public key with equivalent security, you can choose EdDSA (recommended).

Move your mouse randomly in the middle of the window to generate the randomness used to generate the key.

You are now in this screen.

- In the "Key Comment" section, add a relevant comment, so that we know who owns the key, for example your first name.
- Click on "Save public key", and give it a relevant name, e.g. "prenom.pub.key", and save it in a valuable folder.
- Click on "Save private key", validate the warning and give it a relevant name, e.g. "firstname.priv.ppk" and save it in a valuable folder.
NB: If you lose your private key, you lose your access. If you lose your public key, we can't authorize new accesses.
Using an RSA key for SFTP (FileZilla Windows)
Click on the first FileZilla icon ("Site Manager") or on "File" and then "Site Manager".)

- Add a site and name it.
- Select SFTP protocol (default port is 22, not shown by default)
- Choose the "Key File" login type
- Enter the desired user (root or other)
- In "Key File", find your private key