Cipher v public key.

[David Shaw]

On Fri, May 26, 2006 at 05:20:04PM +0100, David Gray wrote:
> Hi all, 
> 
> Just starting a project where one of our customers will be sending 
> encrypted data files from their windows based servers to be 
> decrytpted on our VMS servers.   
> 
> They have not yet decided which product they will use for for encryption 
> but I'm hoping to steer them down the GnuPG path as I've done a quick 
> test and it works perfectly between those two operating systems.  
> 
> One question they have asked which I'm not sure of the answer is that can 
> GnuPG handle the AES256 alogorithm?  The gpg --version on my VMS system 
> shows... 
> 
> $ gpg --version
> gpg (GnuPG) 1.2.3
> Copyright (C) 2003 Free Software Foundation, Inc.
> This program comes with ABSOLUTELY NO WARRANTY.
> This is free software, and you are welcome to redistribute it under certain
> conditions. See the file COPYING for details.
>  
> Home: /SYS$LOGIN/gnupg
> Supported algorithms:
> Pubkey: RSA, RSA-E, RSA-S, ELG-E, DSA, ELG
> Cipher: 3DES, CAST5, BLOWFISH, AES, AES192, AES256, TWOFISH
> Hash: MD5, SHA1, RIPEMD160, SHA256
> Compression: Uncompressed, ZIP, ZLIB

Yes, this can handle AES256.  It's listed, so it can be handled.

> AES256 is listed as a cipher but not a public key?  What is the 
> The difference?  I was hoping to use asymmetric keys with me 
> Giving the public key to the customer.  As mentioned before this all 
> Works fine but I'm not sure which alogorithm I'm using when encrypting. 

You're using both an asymmetric key (RSA, DSA, ELG-E), and symmetric
key (AES, CAST5, TWOFISH, etc) when you encrypt.

> So after all that my question really is, how do I set the alogorithm
> to AES256 in windows so I can test decrypts on VMS?

It's possible you're already using AES256.  Add a "-v" to your gpg
command line when you encrypt to see which cipher it is using.

David