[Cryptography] Steganography and bringing encryption to a piece of paper

[Grégory Alvarez]

2014-07-18 18:19 GMT+02:00 Dave Howe <davehowe.pentesting at gmail.com>:

> Seen an approach to this that relied on transcribing existing text and
> choosing synonyms for the words such that the original meaning was
> preserved; downside was it was a really low bandwidth channel, with only a
> couple of bits per altered word and not every word capable of being altered
> in a sentence without completely changing the meaning.
>

The meaning needs to be altered if we want to hide a message. I was
thinking about extracting a phrase from internet (or a database) that
contain a ciphertext word and use it in the final encrypted message. This
will allow to maintain a coherence between the words. The downsides are :

- You need to send the ciphertext words over the internet to look for
phrases, someone can intercept them. Using a database require a lot of
information and storage. It may not be practical.
- The final message will contain a phrase for every ciphertext word, it's
very long.

I don't think this idea will work.


2014-07-18 22:52 GMT+02:00 Tom Mitchell <mitch at niftyegg.com>:
>
>
> Dictionaries could include old or new international code books..... Like:
> http://howwethink.nkhayles.com/codebooks/texts/
> to improve things.
>

Thanks I will check it out.


2014-07-18 19:41 GMT+02:00 Bear <bear at sonic.net>:


> While not "encrypted" as such, I doubt that anyone who got their
> hands on his journal could, in any reasonable timeframe or possibly
> ever, read it.  With no illustrations or passages in English to
> relate to the written words, the proper nouns are the only
> relationship it has to the real world, and that relationship is
> itself tenuous. To those who had not spent time learning the
> language from someone who, ultimately, learned it from the guy
> who made it up, it should be  as impenetrable as the Voynich
> manuscript.


The Voynich manuscript is a very interesting mystery. Unfortunately since
it hasn't been broken yet, everything is suppositions. William Friedman had
the same idea, he thought it was a kind of synthetic universal language.
Your comment illustrate very well that a cipher needs to be practical. If
you need to spend years learning how to encrypt and decrypt with it, its
utilisation will be very complicated. Another example is a code book with
the famous Beale ciphers. It is very hard to decipher but not as practical
as having a password to remember.
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