Remove a recipient from a message without viewing it

[Nicolas Boullis]

Hi,

On Sun, Nov 21, 2010 at 04:31:21AM -0500, Nathan Krasnopoler wrote:
> Is there a way to remove a recipient from a message without having any
> of the private keys needed to view the message?
> 
> For example, is message M is encrypted to Sam, John, and Bob as text
> C, I would like to output C_s that is M encrypted only to Sam, C_j
> that is M encrypted only to John, and C_b that is M encrypted only to
> Bob.
> 
> If this is possible, I think it would also preserve any signatures on M.
> 
> I would prefer to do this in a python interface, but a shell/gpg or a
> C interface is also workable.

For what it's worth, a few months ago, I decided to write a 
gpg-edit-recipients tool. I announced it on thi list (see 
http://www.mail-archive.com/gnupg-users@gnupg.org/msg13495.html).

My project is on standby because I haven't seen much interest in this 
tool, but if you are really interested, I guess it could be resurrected.

However, for your specific need, you don't even need such a tool, I 
think you may split your encrypted message with gpgsplit, and then 
concatenate the relevant packets together.


Cheers,

-- 
Nicolas Boullis