🚀 go-pugleaf

> Keys that can be carried in one's head (or looked up in commonly available
> books) have a practical advantage here, although they are not absolutely
> secure.

A tip for the aspiring spies :-) in the audience:

Using the text of a book as the key isn't very secure, because a key which
is English text shows strong patterns (although using a book written in
some obscure language might help...).  An easy way to make life much harder
for the cryptanalysts is to use a book of *numbers*, say trade statistics
or something like that.  Those numbers will show patterns, but they'll be
obscure and they won't be the ones the cryptanalysts are looking for.
-- 
Those who do not understand Unix are |  Henry Spencer @ U of Toronto Zoology
condemned to reinvent it, poorly.    | {allegra,ihnp4,decvax,utai}!utzoo!henry