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Challenge "Cascading Encryption — Part 1/3"

Challenge "Cascading Encryption — Part 1/3"  

  By: Javex on Jan. 25, 2013, 11:54 a.m.

Can you break this cascading encryption that consists of a combination of substitution and transposition? The solution contains important information for the next parts.
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 Last edited by: admin on Oct. 31, 2021, 2:55 a.m., edited 1 time in total.

Re: Challenge "Cascading Encryption - Part 1/3"  

  By: wackerao on Jan. 25, 2013, 7:01 p.m.

Please note, that there has been a mixup with this challenge - when you view or download it you actually get a very old challenge (wacker-01) and not the new one. The administrator is informed and hopefully this matter will be resolved soon.

Clearly, entering the codeword from the old challenge (wacker-01) is not the correct answer. (I could see from the log, that this was tried several times..)

Cheers

Re: Challenge "Cascading Encryption - Part 1/3"  

  By: wackerao on Jan. 25, 2013, 7:18 p.m.

Just realized, that I have admin rights here.. thus fixed it.

Now you should get the correct challenge when viewing or downloading this challenge. I also reset the start time to 19:00.

If it does not show the "Cascading Encryption Part 1/3" (Mehrfach-Verschlüsselung Teil 1/3)) for you, then try to refresh your browser, otherwise please contact us.

Cheers,

Re: Challenge "Cascading Encryption - Part 1/3"  

  By: Veselovský on Jan. 25, 2013, 8:23 p.m.

I also reset the start time to 19:00.

Was it necessary? I solved the challenge at 2013-01-25 15:50:34. Now it looks like I solved it before it was even published. This also probably caused that the hall of fame is now displaying 0 points for me for this challenge instead of previous 200.

Re: Challenge "Cascading Encryption - Part 1/3"  

  By: wackerao on Jan. 25, 2013, 8:40 p.m.

Well, it was not strictly necessary, I just thought it to be fair, since it was kind of impossible to solve it without having the actual challenge (actually, it is technically unclear to me how you where able to download the challenge during this time, but I know there was a way, since at first when I tested it, I also got the correct one, but never again after that)

Anyway, I set the starting time now to 15:00 and you got your points back - seems that the system does not like negative solving times.

Cheers,

Re: Challenge "Cascading Encryption - Part 1/3"  

  By: Veselovský on Jan. 25, 2013, 8:46 p.m.

actually, it is technically unclear to me how you where able to download the challenge during this time

I simply clicked the link as usually and the right challenge opened. I really have no idea why other users had problems with it.

Re: Challenge "Cascading Encryption - Part 1/3"  

  By: wackerao on Jan. 25, 2013, 8:58 p.m.

Well, as I said, it also worked once for me - for no apparent reason. Seems you have been lucky :)

Cheers,

Challenge "Cascading Encryption - Part 1/3  

  By: Theofanidis on March 26, 2013, 2:56 p.m.

Hello everybody

Regarding the first part of the Part 1 of this challenge (Caesar part) i only managed to distinguish what shift is needed.

Do we kneed the codeword from the Caesar shift to find the Vigenere-autokey (Part 2) of this challenge ?

I cannot understand if the hint that the same column transposition was used will help us solve the second part or both . . .

Could / Should an - even 4 letter word - be given as an extra hint so as to determine somehow in what manner columns are arranged - as it was done in the "Molehunt" series ?

Keep in mind that not all members have native language German . . .

I also respect the fact that "already 11 members have solved this challenge", but giving this small hint might enable more to solve this challenge and the Level II challenge that up to now has not yet been solved

Best regards
George Theofanidis

Re: Challenge "Cascading Encryption - Part 1/3"  

  By: wackerao on March 27, 2013, 12:44 a.m.

Hi there,

first, lets distinguish between the three parts of this challenge and the two messages in the first part. Therefore, we are talking right now about solving message 1 and message 2 from part 1.

From message 1 you can learn the key which was used for the transposition. You started correctly by blindly stripping away the Caesar.

Now, the hint in challenge tells you, that in both messages, the same transposition was used. Hence with the knowledge of the transposition-key, you can remove the transposition from message 2. What remains is only the Autokey, which should not be hard to solve.

As for solving the transposition cipher.. well the hint is there: it has a key length of 13 and it is ciphertext-only, thus nothing is known. However, nowadays a key length of 13 isn't beyond reach of todays computers. Additionally it is pretty easy with a more sophisticated ciphertext-only attack on transposition ciphers. Thus, this transposition was not meant to be attacked in the same way as the transposition used in the molehunt series. Additionally, language skills (i.e. german) are not really required for finding this solution. Therefore, maybe another hint would be that although this is a level I challenge, you probably need a computer, but the algorithms are out there..

The hints for solving part 2/3 (ie. the ADFGVX-challenge) are given in the decrypted cipher-text ….and text-structure.

Happy decrypting :)
Arno

Challenge "Cascading Encryption - Part 1/3"  

  By: Theofanidis on March 27, 2013, 8:22 a.m.

Dear Arno

Thanks for your reply

My only objection is that since it is a Level-I challenge it should be solved by pen and paper only - as stated for all Level I challenges - and not by using computers or special algorithms . . .

Best regards
George Theofanidis

Re: Challenge "Cascading Encryption - Part 1/3"  

  By: wackerao on March 27, 2013, 1:36 p.m.

Dear George,

yes, I know [HTML_REMOVED] - I helped in designing the definitions for the levels [HTML_REMOVED] :). However, challenges which can be solved almost automatically by using the right tool, which is publicly available (and referenced in the level I definition) do not qualify as higher than level I.

Nevertheless you are right, there is a sentence in the level I definition stating that "You don't need a computer for solving level I challenges". Well, this might be a statement which is to strict. Maybe it should be rephrased into "You might not even need a computer for solving level I challenges." or similar – we will discuss this internally and decide how to solve this little discrepancy.

Cheers,
Arno

Re: Challenge "Cascading Encryption - Part 1/3"  

  By: hansemak on April 25, 2013, 4:41 p.m.

Hi there,
i decrypted both texts and found the codeword. but it is not accepted.
so i get no cookie?

Challenge "Cascading Encryption - Part 1/3"  

  By: Theofanidis on April 29, 2013, 9:43 p.m.

Dear hansemak

I have posted a PM regarding your questions

Best regards
George Theofanidis

Re: Challenge "Cascading Encryption - Part 1/3"  

  By: bgr on Dec. 18, 2013, 8:45 p.m.

From message 1 you can learn the key which was used for the transposition. You started correctly by blindly stripping away the Caesar.

I think I am on the wrong track.
To get the key from message 1, I stripped away the Caesar, like Arno explained. I only found one Caesar shift where the result fits to the german letter frequency. But then I cannot identify one single word, independant how I re-arrange the 13 columns. Looking for typical german bigrams or trigrams was not successful, too. How should it be possible to identify the transposition key, if I cannot find one single useful word?
Bernhard

Re: Challenge "Cascading Encryption - Part 1/3"  

  By: Bart13 on Dec. 19, 2013, 1:46 a.m.

I think I am on the wrong track.

Not completely.

But you can't just swap columns in this columnar transposition as it is an irregular case; the columns don't have the same length….


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