Migrating from PGP to GPG question

vedaal at hush.com vedaal at hush.com
Wed Mar 3 16:29:37 CET 2010

On Mar 2, 2010, at 9:18 PM, Smith, Cathy wrote:

> gpg: WARNING: key 96B12847 contains preferences for unavailable
> gpg:          algorithms on these user IDs:
> gpg:          "pss": preference for cipher algorithm 1
> gpg: it is strongly suggested that you update your preferences 
> gpg: re-distribute this key to avoid potential algorithm mismatch 
> > problems

> When I created my gpg keyring, I selected the default for the 
key, DSA and Elgamml, \
> and a 2048 bit keysize.   
> What are the ramifications of just saying "yes" to the prompt - 
update preferences? \
> How potentially serious is the algorithm mismatch?  I'd like to 
better understand \
> exactly what is happening.

The problem here is one that PGP users can't fix.

No matter what you set the key preferences for, 
PGP (up through 8.x, don't know about 9.x), will insist on using 
IDEA when encrypting to this 96B12847 key. It will just do it that 
way by default, and without the PGP user being able to change it.

So, your practical choices are:
[1] revoke this key
(no problem unless you need to correspond with PGP 2.x users,)

[2] configure your GnuPG for IDEA, if PGP users are still going to 
use this key.

(a)get IDEA from here:

(b)add this line to your gpg.conf
load-extension (wherever you saved idea.dll)\idea.dll

(c) type gpg -h
and see if IDEA is listed.
It should be listed as follows:

Supported algorithms:
Cipher: IDEA (S1), 3DES (S2), CAST5 (S3), BLOWFISH (S4), AES (S7), 
AES192 (S8),

        AES256 (S9), TWOFISH (S10), CAMELLIA128 (S11), CAMELLIA192 
        CAMELLIA256 (S13)
Hash: MD5 (H1), SHA1 (H2), RIPEMD160 (H3), SHA256 (H8), SHA384 
      SHA512 (H10), SHA224 (H11)
Compression: Uncompressed (Z0), ZIP (Z1), ZLIB (Z2), BZIP2 (Z3)

(If you have a gnupg version earlier than 1.4.10, Camellia won't be 


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