I have received encrypted emails which I can not decrypt because the key used for encryption seems not to be correct.

Usually I have a key ID with 8 hex characters. This key can be found on public keyservers.

The emails I've received recently state a value which is different from my public key ID. Enigmail security info:

gpg: decryption failed: No secret key
Note: The message is encrypted for the following User ID's / Keys:
0xYYYYYYYYYYYYYYYY <my email address>

So it states a 16 character hex value which is not similar in any way to my public PGP key ID. However, using this hex value on the search function of a keyserver, I find my email address with my usual public key info. I still can't see the 16 character hex value among that information.

Can anyone tell me what's it with that strange hex value? What's the relation to my PGP key?

  • 2
    The 16-digit value is, or should be, a "long" key ID. There's a discussion here: security.stackexchange.com/questions/84280/… Of course, that doesn't explain why you cannot decrypt the email. – Bob Brown Dec 6 '15 at 21:00
  • 1
    If you find it on the key servers for your usual key, this must be a subkey. Are you missing one of the secret subkeys? – Jens Erat Dec 6 '15 at 21:05
  • The last 8 characters are the short / old key ID. The full ID is the 16 character long string. Did you import your secret key for this public key? – Daniel Ruf Dec 6 '15 at 22:01
  • Yes I imported the secret key, I can decrypt messages that are encrypted with my "normal" key. I'll check the hint with the subkeys, only heard of that but never had to deal with those before. – radix Dec 8 '15 at 20:37

The reason was that gnupg resp. enigmail didn't ask for the passphrase in the first place. I figured out that I needed to install pinentry which provides the dialog for entering the GnuPG passphrase.

For some reason it worked without pinentry before. I guess that a Linux Mint update removed a program responsible for the dialog before and didn't replace it properly (I've been using the current installation for quite a while, starting with Mint 14 and always updating to the next release).

I still wonder about my long key ID shown by enigmail via details -> Enigmail Security Info: the short value is not a part of the long ID, as it should be according to this thread and does not have any similarity.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

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