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I'm using HxD as my hex editor, and I was wondering if it is at all possible to create a comment within the hex code from a specific file. For example I have a picture and I opened it in HxD. Is it possible to write a comment in that code?

Further explanation: you know in html you can place a comment like this or in javascript you can place a comment like this // or /* test */? how do you do that in a hex editor? or is it totally impossible? Any help would be greatly appreciated!

Background information: no im not a hacker. I'm a graphic designer and i want to protect my images. I know it would be easier to use exif or iptc or other metadata tags, but i researched and its easy to remove those tags, rendering my work useless. I noticed with steganography, the image data header remains the same even if the image was tweaked. but if the image is resaved, the hidden text that i put at the bottom of the hex file is removed. if the answer to the above question is no..is there any way to prevent the hidden text from disappearing if the image was resaved?

any help is extremely appreciated! thank you in advance

*Additional information: I found a way to convert a picture into a file repository that prevent you from opening that image with photoshop. unfortunately you can open it with microsoft office and paint. heres the link: http://www.computerhope.com/issues/ch000861.htm I forgot to add that (for example) if you have a .png image you have to make it into a .jpg *

user
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jester113
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3 Answers3

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Hex is not a language or a format spec, it's a way to view binary data, so well yes you can write "comments", as you can write text in file, but it may break your image, so I'd say it depends on its format.

I'm pretty sure there are types of steganography software/libraries that allow you to see if the protection has been broken. You should make some research in this direction.

CharlesB
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There is something called Steganography, which allows you to put hidden information into images.

On Code Project, there is one author who has written a lot of articles about it. E.g. there is an article to hide information inside an image, and she also has several other articles to hide information in all kind of "containers" with even uncommon thing like hiding binary data in HTML documents.

Uwe Keim
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    Thank you for your reply. Yeah i tried a lot of those free steganography tools, but the hidden message is destroyed wenever the image is re-encoded (or "Save as") but thank you for the links i will definately take this into consideration when uploading my graphics online ^^ – jester113 Apr 27 '12 at 02:43
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In PNG files you can do something like this.

@tEXtcomment.YOUR.Comment.HeRe.XdV

Files have delimiters and vary by file type. Mostly this kind of thing is used for images. If you perform similar searches you can find other file formats.

Sorry not more helpful as Im failing on the terminology, but this comment block works.

As always, save, and test.

roberthuttinger
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