[Nottingham] Can't remember the term for a cryptographic technique...

[Danny King]

Hi all,

A bit off topic so I apologise in advance:

At the last meeting I was having a conversation with a few people and
we briefly touched on cryptography, specifically a certain area of it.
I can't for the life of me remember the term used to describe the
practice of encrypting a message so that two separate keys provide
different plaintexts when used on the same cyphertext i.e.:

Alice creates a cyphertext from her secret message and gives Bob key1
and Fred key2. Bob uses key1 to decode the true message whilst Fred
uses key2 on the same cyphertext to decode a different but still
conceivable message.

Can anyone help me to remember the name of this practice? I've been
googling and wikipeding for an hour with no success!

Thanks!
-- 
- Danny King of Gleaming Pixel Web Design.

Email: danny at gleamingpixel.co.uk / dannyking at gmail.com
Web: www.GleamingPixel.co.uk