Stegospam lets you hide your data in spam to avoid NSA/GCHQ spying. | Hacker News Reader

Stegospam lets you hide your data in spam to avoid NSA/GCHQ spying.

charlieharvey.org.uk

2 pointsciderpunx6 comments

I would be highly surprised if mails (even spam) wouldn't be scanned for steganographically hidden messages (no insider knowledge though). Hell, I would even want this for my own antivirus functionality.

I would be surprised if your stegospam wouldn't have a red flag raised by any scanner which utilizes advanced heuristics. Especially since your stegospam utilizes a form of steganography which is already described into great detail by e.g. David Kahn in The Code Breakers (nice crypto history book).

Yes, I think you might be correct and I do note that my approach is not to be trusted prominently ;-)

I am interested to know what attacks would be possible.

My guess is that you'd look for known sentences -- which you can mitigate by using a custom corpus.

Or you do some sort of statistical analysis on the length of sentences, which is mitigated by distributing the sentence lengths along a standard distribution.

Or you do a statistical analysis for word lengths themselves. But if the data you are hiding is GPGed then this information is not obviously vulnerable to statistical analysis of this type because the character distribution ought to be even (ish).

I suppose you would mitigate against attacks on the length of the messages by splitting your message and sending from multiple accounts.

Are there other attacks that I've missed? I'd love to know.

And I'll check out Kahn's book, thanks for the suggestion.

After stegospam pass, have you not some html redundancy free room to utilize?

Are you aware of deogol, perl, stego?

Not much gained, but there is a scanner how much free space per html file size.

..........................

Deogol

an HTML steganography tool

What is Deogol?

Deogol is a commandline Perl program implementing basic steganography on HTML files

http://hord.ca/projects/deogol/

No wasn't aware of it. I've just downloaded and having a play. Very interesting approach, using tags as the carrying medium.

And for the sake of completeness, I've also found spammimic http://spammimic.com/. There is a paper at: http://www.nic.funet.fi/pub/crypt/old/mimic/mimic.text

Vast markup language, Knuth's TeX, and more so Metafont, provides a huge space as 'carrier medium. For eample, kerning alone, using float/real values far beyond what a human eys can tell. Off the top of my head, ... no, I won't try to guesstimate the dimensions of this carrier medium giant play room single-handedly. It gets messy describing what appears odd and questionable. The foo.tex could potentially grow arbitrarily large.

No compression here, as html, the Tex source is larger than what we view.

Another carrier medium layer to consider:

Per longish decimal variables, eg, in \kern, there is also

arithmetic encoding(See wikipedia)

which maps any size foo onto a real value in (0,1). I think there is a proprietary/patent troll war on this.

Choose natural language with many digits/decimals, tables of sports statistics. A stego, in C I think, around 15 yrs ago, created a familiar baseball sports page with decimal tables. ...etc

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