You could try. My guess is, that it doesn't accept the ElGamal key, 
because these keys have been deprecated.



Closing, because this is not an IMP issue.

After installing GnuPG from backports.org 
(http://backports.org/package.php?search=gnupg) it still doesn't work. 
I thought it could be an old-version-issue :), now its 
1.2.5-2.backports.org.1 instead if 1.0.x.

Do you think it could help to compile and install GnuPG from current sources?

I think I could figure out the problem. That's what print_r($result) 
after  $result = $this->_callGpg($cmdline, 'w', $params['passphrase'], 
true, true) says:



( [output] => [stderr] => gpg: protection algorithm 254 is not 
supported gpg: encrypted with 2048-bit ELG-E key, ID xxxxxx, created 
2004-12-21 "xxxx" gpg: public key decryption failed: unknown cipher 
algorithm gpg: decryption failed: secret key not available gpg: [don't 
know]: invalid packet (ctb=09) [stdout] => )



I think I will find somethin in that direction. Any ideas?

That wouldn't help because you need to debug it on the server side. 
Take a look at the "verifyPassphrase" method in 
lib/Horde/Crypt/pgp.php and try to find out if the correct  passphrase 
reaches this point and what the $result variables actually contain.

Yes, so it is. There are two entries displayed correctly. The only 
thing is that it doesn't accept my passphrase. If you would like i 
could create a test account for you so you could test it yourself.

A dumb question, because someone else happened this recently: are you 
sure that your private key has correctly been exported? The should be 
two entries for your personal key on the PGP page, one for the public, 
one for the private key.

Ok, I tried a passphrase with and another one without special keys 
because this was my first idea. The key is an external one that was 
generated with Enigmail/GnuPT for Windows. Is there any possibility to 
have a debug log while entering the passphrase?

System is Debian Woody with PHP 4:4.3.10-1.dotdeb.0 from Dotdeb.org 
(Backport) and MySQL 4.0.23-0.dotdeb.0; Apache-SSL 
1.3.26.1+1.48-0woody3 with mod-php.

This broad statement is plain wrong. Of course it accepts the correct 
passphrase. It does for everyone else. You need to provide more 
information to make this a useful bug report. Do you have some special 
characters in your passphrase, did you try other keys, other 
passphrases, did you try external keys vs. imp-generated ones, etc.

IMP does not accept the correct passphrase and tells you that the 
passphrase is invalid.