McDougall, Marshall (STEM) Marshall.McDougall at
Thu Jan 24 21:15:53 CET 2008

Thanks to all who responded.  It looks like we are making the decision
to dump IDEA as it's not an officially supported cipher in our

Regards, Marshall 

>-----Original Message-----
>From: gnupg-users-bounces at 
>[mailto:gnupg-users-bounces at] On Behalf Of Todd Zullinger
>Sent: Wednesday, January 23, 2008 1:47 PM
>To: gnupg-users at
>Subject: Re: IDEA
>McDougall, Marshall (STEM) wrote:
>> Hi All.
>> First gentle :-}
>> I have a RHEL server and I am having difficulty decrypting a pgp
>> encrypted file.  Near as I can tell, I need the IDEA cipher.  
>> [user at myserver]# gpg --decrypt myfile.txt 
>> gpg: protection algorithm 1 (IDEA) is not supported
>> gpg: the IDEA cipher plugin is not present
>> gpg: please see for more
>> information
>> gpg: encrypted with 1024-bit RSA key, ID C0A298D3, created 2004-07-13
>>      "one_of_my_keys"
>> gpg: public key decryption failed: unknown cipher algorithm
>> gpg: decryption failed: secret key not available
>> I roamed around the GNUPG site and found the "idea.c.gz" 
>downloads, but
>> the instructions allude to directories that don't exist on my server.
>> Has anyone added IDEA to an existing canned redhat 
>installation?  I am
>> open to any suggestion.  Thanks.
>You can rebuild the gnupg srpm and add idea.  A few small changes to
>the spec file (like in the attached diff) should do what you want.
>A better solution would be to have sender encrypt the file to you
>using a cipher that you can use without any patents or other
>encumbrances.  Does your key have a cipher pref for IDEA?  If so, you
>should fix that so other people don't encrypt things to you that you
>can't easily decrypt.  You can view your prefs with:
>$ gpg --edit-key C0A298D3 showpref quit
>Todd        OpenPGP -> KeyID: 0xBEAF0CE3 | URL:
>I never met a morphosis I didn't like.

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