27 replies to this topic

[MichaelZ]

This challenge is dedicated to BDV (and of course to Team Reboot and to reboot.pro).
I hope you enjoy solving it.



http://michael-zoell...description.pdf
http://michael-zoell...enge15image.png

You can also download it here plus you have the possibility to check your solution.

Many Greetings
MichaelZ

P.S. I don't know how to operate the new forum software. I wasn't able to attach those two files. I hope you have no problem to download them using the links.

[Icecube]

Hidden in the PDF:

Spoiler

1523 1596

Which refers to:

Spoiler

Blaise de Vigenère (April 5, 1523–1596) was a French diplomat and cryptographer. The Vigenère cipher is so named due to the cipher being incorrectly attributed to him in the 19th century.

This site might be handy:

Spoiler

http://translate.goo...java%2Fvigenere

I am currently stuck at that point.

[MichaelZ]

I am currently stuck at that point.

That's what I was hoping
BTW, what you found is hidden twice...

Many Greetings
MichaelZ

[Wonko the Sane]

Text/message is seemingly too short/has no repeated sequences to crack it with the Charles Babbage technique.
http://www.simonsing...ere_cipher.html
http://www.simonsing...e_cracking.html


Wonko

[Icecube]

Found the hidden text at the second place:

Spoiler

with the cryptography plugin of Paint.net

Replacing "1523 1596" with the appropriate cipher alphabeth:

ABCDEFGHIJ

0123456789

I get "BFCDBFJG" as key.

The "decrypted" message, doesn't make much sense:

LOTNSGVHOFURINOOZASJWHU

P.S.: I just noticed that the hidden text is not easily retrievable in Acrobat Reader. Evince PDF reader, allowed me to select the text behind the black box. LibreOffice (and probably OpenOffice.org) can open the PDF and allow you to move the black box too so you can see the text.

[MichaelZ]

I get "BFCDBFJG" as key.
The "decrypted" message, doesn't make much sense

Hi Icecube,

it doesn't make much sense because it is not the message... (because it is not the correct key...)

Spoiler

The hint to Vigenère was put twice into the challenge. Once as text hidden in the document below the black box and once in the graphic as steganography. When I prepared the challenge I didn't find out in a timely manner how to put the graphics into the pdf without compressing it so the stegano is not smashed. That's why I added the image as a separate file so my stegano work was not in vain.

The real key is also hidden twice in the challenge...

Many Greetings
MichaelZ

[Icecube]

I noticed before that the F and R in the image are a bit highlighted. But I am not sure if it is on purpose or not.

[Wonko the Sane]

I get "BFCDBFJG" as key.

The "decrypted" message, doesn't make much sense:

LOTNSGVHOFURINOOZASJWHU

But it could be a fine sample of Vogon poetry.
http://en.wikipedia....ki/Vogon#Poetry

In my crystal ball I saw ALTJTHTO

The decoded message doesn't make ANY sense either.

MICHAELZPZDLQLEGAUBDEFK

Unless first part is the name of someone and second part is the censored adjectives quite a few people are throwing at him/her.




Wonko

[MichaelZ]

I noticed before that the F and R in the image are a bit highlighted. But I am not sure if it is on purpose or not.

No it's not on purpose. I didn't even notice before. I can asure that the key is not in the graphic.

Many Greetings
MichaelZ

[MichaelZ]

[...] quite a few people are throwing at him/her.

Hej, I don't want to be thrown at

Many Greetings
MichaelZ

[Wonko the Sane]

Hej, I don't want to be thrown at

Well, then maybe it is time to do what you promised:

I have no idea if this challenge is too easy or too difficult. Please let me know when I
shall give some hint.

And be a little bit less §@ç#ing optimist!

But similar challenges were solved that fast so that I’m quite
optimistic that it is doable.

Wonko

[MichaelZ]

I can asure that the key is not in the graphic.

Another hint: Hey, we are IT people, aren't we? Probably IT knowledge required?

Many Greetings
MichaelZ

[Icecube]

Of course it is doable it the key is not to long (brute force ), but that shouldn't be the purpose of the challenge, I hope.

[MichaelZ]

Of course it is doable it the key is not to long (brute force ), but that shouldn't be the purpose of the challenge, I hope.

The length of the text and key were selected in such a way that I think a brute force is impossible/not very likely to succed. As I mentioned before, it knowlege is required...

Many Greetings
MichaelZ

[MichaelZ]

And be a little bit less §@ç#ing optimist

Hi Wonko,

in the past I was always impressed by your knowledge of the English language. But now...

I think §@ç#ing optimist is correctly spelled φϋ¢к¥йг optimist

Many Greetings
MichaelZ

[Wonko the Sane]

I think §@ç#ing optimist is correctly spelled φϋ¢к¥йг optimist

It depends on the dialect, your spelling seems rusglish, a pure L337 would be PhU(|<1|\|9 or /=|_|(|<!/V6 or fux!n9, I am pretty sure that down under they use something like ɟnɔʞıuƃ , I think there is not one "recommended".


Wonko

[MichaelZ]

I think there is not one "recommended".

I like the down under!

[Icecube]

I can asure that the key is not in the graphic.

Is it visible in the PDF as plain text or in the hexdump of the PDF as plain text?

[MichaelZ]

Is it visible in the PDF as plain text or in the hexdump of the PDF as plain text?

I like HxD very much (although I also like Tiny Hexer for which I have Jaclaz Wonko plugins).

Many Greetings
MichaelZ

[windy]

Is one meant to put "THE********IS**********" or just the password into the checker?

I get a result of "Duplicate entry '0' for key 1"

[Holmes.Sherlock]

Is one meant to put "THE********IS**********" or just the password into the checker?

I get a result of "Duplicate entry '0' for key 1"

Congratulations windy!! What I can see that your answer is absolutely correct.

[Holmes.Sherlock]

@windy
Can you please try again & let us know?

[MichaelZ]

Is one meant to put "THE********IS**********" or just the password into the checker?

windy, also many congratulations from me!

Many Greetings
MichaelZ

[windy]

@Sherlock

The checker is working now, thankyou.

I've only just started looking at these challenges and I am finding them an entertaining diversion.I've done 13 but still stuck on 14

[Holmes.Sherlock]

@Sherlock

The checker is working now, thankyou.

I've only just started looking at these challenges and I am finding them an entertaining diversion.I've done 13 but still stuck on 14

Good to listen that you are enjoying the challenges. Thanks to my Team Reboot companions & forum members.