PGP - Revoking old key from key servers
How to revoke a user ID or key from key servers using GPGTools for Mac or Enigmail
Problem
A key needs to be revoked because it has been compromised or the client has lost their private key or has generated a new key. The client is using Enigmail or GPGTools on Mac.
- The client doesn’t know how to revoke their key.
- The client has lost their revocation certificate.
Solution
It is always a good practice to revoke unused keys from the key servers. Ignoring this may result in confusion, decryption issues, and security/privacy breaches.
An old PGP key may no longer be used because:
- a new PGP key has been created
- access to the secret key has been lost
- the passphrase for the secret key has been forgotten
- a user ID is associated with a new PGP key
Note that revoking a key will require either of the following:
- access to the secret key and passphrase
- a revocation certificate
If neither of the above is available, a revocation will not be possible. In that case, the owner of the key should notify her/his contacts that they should stop using (or delete) the old public key and use the new public key when encrypting email or files addressed at the client.
Enigmail
Instructions on how to revoke a PGP key with Enigmail can be found here.
GPGTools
A guide for revoking a user ID or key from the key servers using GPGtools for Mac can be found here.