How would you do that ...

[Sandy Harris]

Ralph Seichter via Gnupg-users <gnupg-users at gnupg.org> wrote:
>
> * Stefan Vasilev via Gnupg-users:
>
> > How would you solve this task?
>
> With Alice having to rely on cryptography she can do in her head?
> Some shift cipher and carrier pigeons. :-)

Neal Stephenson's novel Cryptonomicon is excellent. I strongly
recommend it to anyone who enjoys reading & is interested in crypto.
Part of the plot involves a cipher that operates a bit like RC-4,
permuting an array, but the array is a deck of cards.
https://www.schneier.com/academic/solitaire/