I found this interesting article on codeproject so I decided to use the idea in an autoit script since it didn't seem to hard
It's basically a way to hide a string inside the bitmap data in a .bmp file. The basic idea is to use just 1 bit of each byte in the bitmap data to save the message, this means that each pixel that is modified inside the bitmap is just modified by one single little color shade (thus making it impossible for a human to notice the difference), so for example 0x000000 becomes 0x000001.
To be able to extract the string you need to know what offset the string is saved into in the bitmap, thus making it smewhat secure for peeping eyes
A big thanks to james3mg for his Number base conversion UDF.
The syntax is easy:
HideMessageInBitmap("file.bmp","My message",SECRET OFFSET HERE)
GetMessageInBitmap("file.bmp",SECRET OFFSET HERE)
Here's a bitmap I have encoded a message at offset 234 for example:
test.bmp 68.4K 558 downloads
UDF ( With Number base conversion UDF):
Bitmap_Message_Hider.zip 3.67K 428 downloads
Ps. Since png doesn't destroy any image data, a encoded message will survive a png conversion
Edited by monoceres, 25 December 2008 - 04:27 PM.