gpg: NOTE: cipher algorithm 9 not found in preferences

Lionel Elie Mamane
Mon Mar 12 23:24:13 2001

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On Mon, Mar 12, 2001 at 10:10:14AM -0800, Nick Andriash wrote:

> BTW, what is the command to see the default list?
gpg --edit-key 0x7BA3FDCE pref Will see a line that looks like: S7 S10 S3 S4 H3 H2 Z2 Z1 Hn (where n is an integer) is the preference for the Hash Zn (where n is an integer) is the preference for the Compression Sn (where n is an integer) is the preference for the cipher Here is the key to the values of n: #define CIPHER_ALGO_NONE 0 #define CIPHER_ALGO_IDEA 1 #define CIPHER_ALGO_3DES 2 #define CIPHER_ALGO_CAST5 3 #define CIPHER_ALGO_BLOWFISH 4 /* blowfish 128 bit key */ #define CIPHER_ALGO_SAFER_SK128 5 #define CIPHER_ALGO_DES_SK 6 #define CIPHER_ALGO_RIJNDAEL 7 #define CIPHER_ALGO_RIJNDAEL192 8 #define CIPHER_ALGO_RIJNDAEL256 9 #define CIPHER_ALGO_TWOFISH 10 /* twofish 256 bit */ #define CIPHER_ALGO_SKIPJACK 101 /* experimental: skipjack */ #define CIPHER_ALGO_TWOFISH_OLD 102 /* experimental: twofish 128 bit */ #define CIPHER_ALGO_DUMMY 110 /* no encryption at all */ #define DIGEST_ALGO_MD5 1 #define DIGEST_ALGO_SHA1 2 #define DIGEST_ALGO_RMD160 3 #define DIGEST_ALGO_TIGER 6 So, e.g., the line given above means: RIJNDAEL, TWOFISH, CAST5, BLOWFISH (implicit 3DES) RMD160, SHA1
> 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...
If you specify a cipher-algo option, no. If you don't specify a cipher-algo optiuon, it will pick an algorithm from the Recipients Key Preferences.
> which I presume is hidden somewhere in his self-signature...
Hmm... Not quite "hidden", but that's where it is, indeed.
> or am I *forcing* the Recipient to accept encrypted messages using
> Rijndael-256?
By specifying "cipher-algo RIJNDAEL-256", you are forcing him. --=20 Lionel Elie Mamane RFC 1991 (PGP 2.x) 2048 bits Key Fingerprint (KeyID: 20C897E9): 85CF 986F 263E 8CD0 80FD 4B8C F5F9 C17D OpenPGP DH/DSS 4096/1024 Key Fingerprint (KeyID: 3E7B4B73): 9DAD 3131 3ADA F50B D096 002A B1C4 7317 3E7B 4B73 --G4iJoqBmSsgzjUCe Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.4 (GNU/Linux) Comment: For info see iD8DBQE6rUvNscRzFz57S3MRAu/1AJ9A7FnhbLM+UJOnukLU50ev7mfPpACgl7tf VQH8d9R5U2r0IEmyIHzGkx4= =Bfe7 -----END PGP SIGNATURE----- --G4iJoqBmSsgzjUCe--