You can sign commits locally using GPG or S/MIME.

Note: GitHub Desktop does not support commit signing.

Tips:

To configure your Git client to sign commits by default for a local repository, in Git versions 2.0.0 and above, run git config commit.gpgsign true. To sign all commits by default in any local repository on your computer, run git config --global commit.gpgsign true.

To store your GPG key passphrase so you don't have to enter it every time you sign a commit, we recommend using the following tools:

  • For Mac users, the GPG Suite allows you to store your GPG key passphrase in the Mac OS Keychain.
  • For Windows users, the Gpg4win integrates with other Windows tools.

You can also manually configure gpg-agent to save your GPG key passphrase, but this doesn't integrate with Mac OS Keychain like ssh-agent and requires more setup.

If you have multiple keys or are attempting to sign commits or tags with a key that doesn't match your committer identity, you should tell Git about your signing key.

  1. When committing changes in your local branch, add the -S flag to the git commit command:

    git commit -S -m your commit message
    # Creates a signed commit
    
  2. If you're using GPG, after you create your commit, provide the passphrase you set up when you generated your GPG key.

  3. When you've finished creating commits locally, push them to your remote repository on GitHub:

    git push
    # Pushes your local commits to the remote repository
    
  4. On GitHub, navigate to your pull request.

  5. On the pull request, click Commits. Commits tab on a pull request

  6. To view more detailed information about the verified signature, click Verified. Signed commit

Further reading