How would you do that ...

[Stefan Vasilev]

Sandy Harris wrote:

> 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/

I remember Bruce Schneier's Solitaire. One can also use the Elsie Four 
(LC4) cipher for that.

The task, however, is also communicating (daily) without logging into 
any services and if

required to send larger documents, or even photos.

Regards

Stefan