Draft informational spec to offer guidelines on the use of steganography

[gnarea]

Steganography could allow users and couriers to conceal Awala traffic (parcels and cargoes) in files that appear to be allowed by the local regime -- Like a video of a cat, which contains an E2E encrypted parcel, which in turns contains a tweet to be posted to twitter.com.

Pros:

• In countries with national intranets, couriers -- or indeed gateways -- could leverage that intranet to transmit Awala traffic via email (Draft "PoEmail" binding to relay parcels via email #40, Draft "CoEmail" binding to relay cargo via email #41) or a local social network, for example.
• This would make it safer to transport cargo in (unencrypted) external harddrives.
• Even if the gateway or courier apps are uninstalled -- by hand or by a duress code mechanism -- the parcels/cargo could survive in the phone's gallery.

Cons:

• The signal-to-noise ratio would be pretty bad.

We should ideally use encoding algorithms that take a series of parameters that are kept secret (only known to the sender and the recipient, like a shared key). This would allow us to use one generic algorithm with open source implementations, instead of many proprietary algorithms with closed source implementations that have to be replaced as censors uncover them.