When you set up SSH, you will need to generate a new SSH key and add it to the ssh-agent. You must add the SSH key to your account on GitHub AE before you use the key to authenticate. For more information, see "Generating a new SSH key and adding it to the ssh-agent" and "Adding a new SSH key to your GitHub account."
You can further secure your SSH key by using a hardware security key, which requires the physical hardware security key to be attached to your computer when the key pair is used to authenticate with SSH. You can also secure your SSH key by adding your key to the ssh-agent and using a passphrase. 詳しい情報についてはSSH キーのパスフレーズを使うを参照してください。
To maintain account security, you can regularly review your SSH keys list and revoke any keys that are invalid or have been compromised. 詳細は「SSH キーをレビューする」を参照してください。
If you're a member of an organization that provides SSH certificates, you can use your certificate to access that organization's repositories without adding the certificate to your account on GitHub AE. You cannot use your certificate to access forks of the organization's repositories that are owned by your user account. 詳しい情報については、「SSH 認証局について」を参照してください。