

Steganography done with JavaScript - eigenschinkpete
http://www.peter-eigenschink.at/projects/steganographyjs/

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0x09
Unfortunately alpha-channel steganography is one of the simplest and most
trivially detected of image steganography algorithms, making it not very
useful. For an example of what goes into a serious and secure steganographic
algorithm see perturbed quantization:

[http://dde.binghamton.edu/download/pq/Fri05pq.pdf](http://dde.binghamton.edu/download/pq/Fri05pq.pdf)

[http://dde.binghamton.edu/download/pq/](http://dde.binghamton.edu/download/pq/)

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darkxanthos
"Hiding" your data in the alpha channel of most images doesn't really seem at
all secure to me. That's like hiding your valuables by placing them in your
basement.

Steganography that I'm used to seeing intertwined ones data with the actual
image data. Which is much more difficult to detect (though certainly not
undetectable).

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Toenex
There is a joke here somewhere about pictures and specific number of words. I
just can't work it out.

~~~
rorrr2
A picture is worth a thousand DWORDS.

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kybernetikos
I had issues with precomputed alpha when I played with storing data in the
alpha channel of images in the browser. In the end, since I didn't really need
to 'hide' the data, I just wrote a few pixels at the top of the image, but
even then, I found some services (i.e. gravatar) was modifying the pixel
values slightly. I had to just use a bunch of the most significant bits from
each pixel.

If you're interested why I was playing with all this, it was for storing
public keys in gravatar images:
[http://kybernetikos.github.io/VisualSecrecy/](http://kybernetikos.github.io/VisualSecrecy/)

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tarikozket
I didn't see a useful answer on "Why use steganography.js?" block, it just
explains "How?".

I wonder answers about "When and why?" questions. Can you guys answer it?

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spookylukey
This doesn't really attempt to hide the fact of communication from computers -
only from humans casually viewing the image.

steghide has a far superior approach:

[http://steghide.sourceforge.net/](http://steghide.sourceforge.net/)

But that can be broken too:

[http://dl.acm.org/citation.cfm?id=1578445](http://dl.acm.org/citation.cfm?id=1578445)

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franze
@eigenschinkpete come by the next viennajs meetup (www.viennajs.org) next
wednesday there will be a talk about a similar topic

