Using the command line:
I use PGP with my emails mostly to sign with digital signature. For some reasons I had to create a new PGP key and revoke my last key (0x43687201) from public key servers like pgp.mit.edu. Key revocation might be necessary for many reasons. Someone might lost his laptop for example. Hence, it’s wise to create a revocation certificate just after the key is generated. I generated it with the following command:
A revocation key indicates that the respective key is comprised, superseded or no longer used. Generating a revocation key only needs passphrase and then an ascii-armoured key block is printed out. Paste this text into a file. In my case, it looked like this:
If you have a backup of your original key pair (which is always recommended) you can generate the revocation key any time later. However, I generate it as soon as I create my key and keep a back up of the original key pair as well as the revocation key.
Anyways, as this was my new computer, I imported my public key using the following command:
Now, I need to import my revocation certificate as well using the command:
After that, I issued the following command to push my revocation certificate to MIT Key Server
I can now check the status of the key from pgp.mit.edu. It shows *** KEY REVOKED ***
By the way, my new key is 0x94E4C396.
Using the web interface of a public key server:
An alternative (if your revocation certificate is an ASCII-armored file, thus not binary) would be to use the web interface of any keyserver of your choice (MIT, Ubuntu etc.), where you can directly paste the revocation certificate.