Duress codes

[s1018954 at aix2.uottawa.ca]

On Tue, 17 Oct 1995, Nathan Loofbourrow wrote:

> Duress PINs liberally sprinkled through the keyspace also drop the
> efficacy of brute-force PIN search for the thief.
Was there an actual protocol for doing this? (probabilistic maybe?)
Don't remember Schneier doing anything beyond just mentionning it. (ok I 
can't find the page number either, so I can't really complain).