gpg: NOTE: cipher algorithm 9 not found in preferences

Nick Andriash Nick Andriash <>
Mon Mar 12 19:30:04 2001

Hash: SHA1

On March 12, 2001 at 8:48:44 AM, Stefan H. Holek wrote:

> NOTE: cipher algorithm 9 not found in preferences

> This means something like:

> a) You have selected RIJNDAEL256 (sym 9) as your symmetric alg
Yes, I would prefer to encrypt messages and receive encrypted messages using that Algorithm, but if that particular Algo is not found in the Recipients Key preferences, then I would want GPG to use the first Algorithm listed in their preference list. Is that possible?
> b) The key you have been encrypting to is not offering this algorithm in its preferred
> sym alg subpacket.
> If you type gpg --list-packets thekeyfile.asc you might see: ...
> hashed subpkt 11 len 5 (pref-sym-algos: 7 10 3 4)
> ...

> Which means: RIJNDAEL128, Twofish, CAST5, Blowfish

> c) GnuPG has used sym alg 9 for encryption (as told) and gives the
> mentioned notice when decrypting.
But in my case, the Recipient is me, and the Key was generated with Rijndael-256 as my preferred Algorithm. The note in that case is telling me that Rijndael-256 is not available. So, if it's not available, what Algorithm was used? When I type --version, I am shown the following: Supported algorithms: Cipher: 3DES, CAST5, BLOWFISH, RIJNDAEL, RIJNDAEL192, RIJNDAEL256, TWOFISH By looking at the above list, I am presuming that Rijndael-256 *is* available, so I am a little confused why I am getting that notation when I send an encrypted test message to myself. BTW, is that my preference list?
> d) There should be no need to specify a sym alg in normal operation
> as it will automatically be selected form the key preferences.
So in that case, cipher-algo should be left blank, but that does not seem to be possible when editing your GPG Options through GnuPGTray. Can I therefore simply delete the cipher-algo line in my Options File? Basically, through my Options File I want to say to others that I prefer to receive messages encrypted using the Rijndael-256 Symmetric Algorithm, but if you don't have that capability, then use Twofish, and failing that, use 3DES, then CAST5 followed by Blowfish. Now, in my case where I am using a precompiled binary for use in Windows, is it possible to edit my Preference List, or do I have to accept the default? BTW, what is the command to see the default list? With reference to *sending* encrypted messages, my preference again would be Rijndael-256. If however, the Recipient cannot accept that Algorithm, does GnuPG use the first of the preferred Algorithms on the Recipients Key Preferences... which I presume is hidden somewhere in his self-signature... or am I *forcing* the Recipient to accept encrypted messages using Rijndael-256? Nick -=N.J. Andriash | Vancouver, B.C. Canada=- [ TB! v1.52 Beta 1 | Win 98 SE 4.10 2222 A ] [ GnuPG v1.0.4-1 (MingW32) | Key ID: 0x7BA3FDCE ] __________________________________________________ -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.4-1 (MingW32) - GnuPGshell v1.60 Comment: Join PGP-Basics: iD8DBQE6rRD7xQKEdHuj/c4RAuqlAJ9fgQNdPEJRwqG1RpNjZ3HXh5kEkQCfSezO xyK4ZhVWxLQGxmnad3//pVE= =/Hzi -----END PGP SIGNATURE-----