Shoutbox

anyone seen the film Along Came A Spider?

the little girl passes notes in class use .gif images with "stago" coding and the investigator tells the cop guy its a string of texts hidden in the 0's and 1's and cannot be read without a password....

what i was wondering is this an actual method of 'passing notes' so to speak or is it just a film thing... sometimes films are based on real life things thought this may be?

yeh ive seen a film like that (if its in russia or sumthing its the same one probably)

i doubt its real though

you could of course send a passworded zip with a text file in it

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Originally posted by Lee Jeffery
yeh ive seen a film like that (if its in russia or sumthing its the same one probably)

i doubt its real though

you could of course send a passworded zip with a text file in it

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russia? might be finking of the russian prince or whoever the lil kid is, i no hes somethings soviet..i cant rmemeber im watchin it but not up to that yet... hes the one shes passing the notes to.....

could send a zip but i found this interesting lol.

real?

Such a method of encoding stuff inside other file formats is as old as the computer industry.

As a matter of fact, in the past there were many contests where people had to try to "crack" the implemented messages in Word documents, GIF files, graphical data, etc... (I also once participated with one of those contests back in the 80's)

Thus, no this isn't simply a movie-thing. It actually exists and is "used" widely and information about this can be found on many sites around the web. (This method of encapsulating messages inside other "normal" formats has an actual name, but I forgot it )...

You have seen those pieces of paper with some little holes that, when placed over a certain text, revealed a secret message, don't you?

Well, the system is similar, but it happens bitwise in here, so it's a huge number of holes to get a decent text message (at least 8 holes ofr a letter)

You can add information, like text,  to images so that you can't see it viewing the image. I have no idea how you could protect it.

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Originally posted by CookieRevised
Such a method of encoding stuff inside other file formats is as old as the computer industry.

As a matter of fact, in the past there were many contests where people had to try to "crack" the implemented messages in Word documents, GIF files, graphical data, etc... (I also once participated with one of those contests back in the 80's)

Thus, no this isn't simply a movie-thing. It actually exists and is "used" widely and information about this can be found on many sites around the web. (It also has an actual name, but I forgot it)...

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kool woah 80's thats to new for my ict teacher this should wind him up, lol

I think this is called steganography.

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Originally posted by KeyStorm
I think this is called steganography.

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Yeah, I was just about to post that. Here's some linkage...

http://www.webopedia.com/TERM/S/steganography.html
http://en.wikipedia.org/wiki/Steganography

Quite interesting. I've heard about it but never bothered to try it.

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Originally posted by Vilkku
You can add information, like text,  to images so that you can't see it viewing the image. I have no idea how you could protect it.

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It isn't about adding comments or stuff like using the author field to add messages, nor is it about pasword protecting files like Lee Jeffery suggested, but it is about actually using unused bits and bytes or using unsignificant bits and bytes to encode messages (like KeyStorm said). For example: bits and bytes wich normaly would be used to contain graphical data.

a very crude example of one possebility:
when you save the pixels of an image the actualy pixel values are saved. If you construct your image (or rather the colors) so that you use only high values, the lower values wouldn't make much of a difference (especially when you use many colors like in 32bit graphics). In other words, you can use the lower bit values to encapsulate text messages.

pixel values (bitwise) for four original pixels: 01100000 11110000 11100000 10010000

Now for the human eye a pixel value of 01100000 will be roughly the same as 01101010. So you can use the lower 4 bits to actually hold text information. and when you combine such two lower fields of 4 bits, you have 1 full byte, in other words 1 character.

Thus when we save our image we can instead of saving
  01100000 11110000 11100000 10010000
save
  01101001 11110000 11101101 10011001
and thus the lower bit fields will be
  1001 0000 and 1101 1001
and they are the ASCII codes for:
  10010000 = H
  11011001 = i

When viewing this image, you will notice nothing out of the ordinary. But put through the correct decoder, it can extract the plain text message "Hi".

This is one of billions of possible methods you can use. Another group of encoding is by manipulating graphic data so it contains other graphical data (this can of course be text again, but it must be viewed with a graphic editor in that case, so it isn't quite the same as extracting plain text from something, but the technics are the same though).


(and of course you could protect it by any method you choose like coding the text further with a password or something only you and the reciever would know... now isn't this fun for all you paranoid people I'd suggest you all to investigate all those graphics found on the net for hidden messages lol)

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Originally posted by KeyStorm
I think this is called steganography.

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yup, that's the one

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Originally posted by WDZ
http://en.wikipedia.org/wiki/Steganography

Quite interesting. I've heard about it but never bothered to try it.

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That one shows indeed a very nice exmaple of another method of encapsuling graphic data within another graphic.