If you don't have an existing GPG key, you can generate a new GPG key to use for signing commits and tags.

Supported GPG key algorithms

GitHub supports several GPG key algorithms. If you try to add a key generated with an unsupported algorithm, you may encounter an error.

  • RSA
  • ElGamal
  • DSA
  • ECDH
  • ECDSA
  • EdDSA

Generating a GPG key

Note: Before generating a new GPG key, make sure you've verified your email address. If you haven't verified your email address, you won't be able to sign commits and tags with GPG. For more information, see "Verifying your email address."

  1. Download and install the GPG command line tools for your operating system. We generally recommend installing the latest version for your operating system.
  2. Open TerminalTerminalGit Bash.

  3. Generate a GPG key pair. Since there are multiple versions of GPG, you many need to consult the relevant man page to find the appropriate key generation command. Your GPG key must use RSA with a key size of 4096 bits.

    • If you are on version 2.1.17 or greater, paste the text below to generate a GPG key pair.

      gpg --full-generate-key
      
    • If you are not on version 2.1.17 or greater, the gpg --full-generate-key command doesn't work. Paste the text below and skip to step 6.

      gpg --default-new-key-algo rsa4096 --gen-key
      
  4. At the prompt, specify the kind of key you want, or press Enter to accept the default RSA and RSA.

  5. Enter the desired key size. We recommend the maximum key size of 4096.
  6. Enter the length of time the key should be valid. Press Enter to specify the default selection, indicating that the key doesn't expire.
  7. Verify that your selections are correct.
  8. Enter your user ID information.

    Note: When asked to enter your email address, ensure that you enter the verified email address for your GitHub account. To keep your email address private, use your GitHub-provided no-reply email address. For more information, see "Verifying your email address" and "About commit email addresses."

  9. Type a secure passphrase.

  10. Use the gpg --list-secret-keys --keyid-format LONG command to list GPG keys for which you have both a public and private key. A private key is required for signing commits or tags.

    gpg --list-secret-keys --keyid-format LONG
    

    Note: Some GPG installations on Linux may require you to use gpg2 --list-keys --keyid-format LONG to view a list of your existing keys instead. In this case you will also need to configure Git to use gpg2 by running git config --global gpg.program gpg2.

  11. From the list of GPG keys, copy the GPG key ID you'd like to use. In this example, the GPG key ID is 3AA5C34371567BD2:

    gpg --list-secret-keys --keyid-format LONG
    /Users/hubot/.gnupg/secring.gpg
    ------------------------------------
    sec   4096R/3AA5C34371567BD2 2016-03-10 [expires: 2017-03-10]
    uid                          Hubot 
    ssb   4096R/42B317FD4BA89E7A 2016-03-10
    
  12. Paste the text below, substituting in the GPG key ID you'd like to use. In this example, the GPG key ID is 3AA5C34371567BD2:

    gpg --armor --export 3AA5C34371567BD2
    # Prints the GPG key ID, in ASCII armor format
    
  13. Copy your GPG key, beginning with -----BEGIN PGP PUBLIC KEY BLOCK----- and ending with -----END PGP PUBLIC KEY BLOCK-----.

  14. Add the GPG key to your GitHub account.

Further reading