downloadbrowsejosh's SMS

Download Short_Message.zip, 90 kb (password: crackmes.de)
Browse contents of Short_Message.zip

You have to embed the message "Attack at early dawn!" into an image to solve the challenge.

The problem:
The attached SW (.NET exe GUI frontend and C++ DLL backend)
contains a detector for a message hidden in an image. In case
it finds a suitably embedded message, it displays that message (and the image, too).

The rules:
Write a SW to embed a message into an image in such way that the attached detector displays it.
A valid solution contains
- The embedder SW,
- An image modified by this SW, containing the "Attack at early dawn!" message.
The image must have suffered no or only little visible distortions due to the embedding.
- Description of the solution.

You may use the attached "Lena" image for embedding.

Difficulty: You decide in case the suggested level 3 is not appropriate.
Tested on Windows 7, XP

Have fun!

-josh

Difficulty: 2 - Needs a little brain (or luck)
Platform: Windows
Language: C/C++

Published: 16. Apr, 2012
Downloads: 596

Rating

Votes: 4
Crackme is nothing special.

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Solutions

Solution by redoC, published 28. jul, 2012; download (422 kb), password: crackmes.de or browse.

redoC has rated this crackme as quite nice.

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Discussion and comments

redoC
12. May 2012		do you have functional keygen for this?
josh
Author
16. May 2012		Yes, of course I have a message coder.
jfmherokiller
03. Jun 2012		I just ruled out one possibility hiding the message at the end of the file in a null buffer.
jfmherokiller
03. Jun 2012		nvm i mistyped the message
jfmherokiller
03. Jun 2012		nope i was right that does not work
mylovestar1
12. Jun 2012		Please check the short_message_crack, Two key points in the .exe and .dll
iLovro
14. Jul 2012		1 off topic question: is that lena151?
iLovro
14. Jul 2012		After a little of googling I found out that was not lena151. :)
redoC
26. Jul 2012		solution coming soon
josh
Author
30. Jul 2012		nice work, redoC. You may play around with your algo and get some roubstness with respect to moderately compressed jpegs too.

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