Cryptography Stack Exchange is a question and answer site for software developers, mathematicians and others interested in cryptography. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Is it possible for myself to change the key size (say from 2048 to 4096) on an EXISTING PGP / GPG key, and just republishing that key?

Or do I have to generate a new key all together?

I want to say that you have to create a new key pair, but I don't have enough documentation either way to support a claim.

share|improve this question
Have a look at this answer I gave on SuperUser for a similar question. – Jens Erat Jul 7 '13 at 19:12
That's what I figured, thank you for the write up. I copied it as-is and cited the answer and yourself down below. Please feel free to answer this question exactly the same and I'll mark your answer right (I can't mark mine for a few days) – Urda Jul 8 '13 at 6:36
If main parts of your answer aren't written by yourself, you should mark them as "Wiki Answer". – Jens Erat Jul 8 '13 at 8:33
Ah I see that option now! Thanks! – Urda Jul 11 '13 at 20:54
up vote 3 down vote accepted

Thanks for the info Jens Erat

There is no way to "upgrade" an OpenPGP key. You will have to create a new one, and you will loose your reputation in the web of trust.

Think about:

  • Giving your new key with the old one, so other could follow the signatures
  • Revoking the old one after some time
  • Using a seemingly unnecessary large key as primary key and smaller subkeys for day-to-day usage. You will never need the primary key for anything but signing other keys (which is rare) and others verifying your signatures (cheap anyway).


share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.