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Challenge "Caesar Encryption"

Challenge "Caesar Encryption"  

  By: admin on Oct. 21, 2010, 4:26 p.m.

The Caesar encryption, a very simple example of a monoalphabetic substitution.
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 Last edited by: admin on Oct. 31, 2021, 2:54 a.m., edited 1 time in total.

Re: Challenge  

  By: Tom on Oct. 22, 2010, 5:29 p.m.

Hallo, beim Senden der Lösung erhält man folgenden Fehler:

Warning: fopen(/usr/local/www/apache22/data/cryptochallenge/logs/challenges.log) [function.fopen]: failed to open stream: No such file or directory in /usr/local/www/apache22/data/cryptochallenge/modules/mod_displayc3challenges/helper.php on line 104
can't open file

Re: Challenge  

  By: admin on Oct. 22, 2010, 6:38 p.m.

Danke für den Hinweis, Fehler behoben. Dazu bitte auch folgendes unbedingt lesen: http://www.mysterytwisterc3.org/index.php/en/forum/viewtopic.php/f,3/t,93/

What should be entered as answer in Caesar Challenge?  

  By: ak187 on Oct. 22, 2010, 9:43 p.m.

Hi,

i decrypted the given text (at least I think so), but I don't know what to enter in the answer box (the whole decrypted text???).

Could someone clarify this?

regards,
anibal

@Admin: Can you move this post into the right section (Challenge "Caesar Encryption"). Somehow it ended up in the wrong place… sorry

Re: Challenge  

  By: admin on Oct. 22, 2010, 10:33 p.m.

@ak187: Yes, you have to post the whole text. Check if everything is spelled right and you have the correct numbers.

Re: Challenge  

  By: crazyboy on Nov. 2, 2010, 2:37 a.m.

hi, i decrypted ciphertext and get a cleartext, but can't submit it. Try sometimes but still wrong. How can i check my solution with another people, or give me what i wrong ?

Re: Challenge  

  By: Javex on Nov. 5, 2010, 1:36 p.m.

Hello crazyboy,

I double-checked and the solution you should provide is correctly implemented so if you got the correct one, you are able to complete the challenge.

I will provide you with some hints though since this one can be a bit tricky:
Watch that you get the cases right. The solution is a normal english text (the letters are both upper and lower case).

The alphabet has 62 characters (52+10) so you might want to check that too.

Combine this with a bit of logic (you have to read the solution and think a bit ;) )

I hope this gets you on the right track.

Re: Challenge  

  By: crazyboy on Nov. 5, 2010, 5:41 p.m.

i got a clear text, all of that is normal English.

hmm, solution only a-zA-z0-9 and space " " ??? is it contained ",.!-" ???

have irc for this wargame ?

Re: Challenge  

  By: be on Nov. 5, 2010, 8:50 p.m.

i got a clear text, all of that is normal English.

Yes, the solution is normal English text. Take care about the order of the sets building up the alphabet. You may have words like "encrYpt" in your solution – if so, there is still something to correct.

Re: Challenge  

  By: crazyboy on Nov. 6, 2010, 2:03 p.m.

i got a clear text, all of that is normal English.
[/quote:2dw28edq]
Yes, the solution is normal English text. Take care about the order of the sets building up the alphabet. You may have words like "encrYpt" in your solution – if so, there is still something to correct.[/quote:2dw28edq]

hmmm, clear text contain ".,!-" or any special character ?
[[be]
hmm what wrong ?

Re: Challenge  

  By: be on Nov. 6, 2010, 5:38 p.m.

hmmm, clear text contain ".,!-" or any special character ?

We left the non-alphabet characters (like blank or exclamation mark) within the plaintext and at the same position also in the ciphertext (so the enciphering process just ignored them which was a wide-spread behavior in the very past). This means, only the characters of the plaintext which belong to the alphabet are substituted. Not to delete the non-alphabet characters weakens the cipher dramatically and is of great help for the cryptanalyst – so its a level-1 challenge …
On the other hand we made it a bit more triggy by using a non-standard alphabet (62 instead of 26 characters) where you have to find the right order of the buildung sub-sets or correct your solution manually at the end.
To send in a correct plaintext, please leave the non-alphabet characters where they are.

Remark: I deleted your link to your solution. Please don't put a correct or almost correct solution in the internet or in this forum. Its better to ask questions here like you do, and the MTC3 team helps with giving hints.

Re: Challenge  

  By: lala22 on March 30, 2011, 7:54 a.m.

Nice one :)

Re: Challenge  

  By: haegarq on April 6, 2011, 7:41 p.m.

Tach auch,

wo bzw. wie kann ich feststellen, was ich falsch mache?

Ich habe den Text wie folgt "entschlüsselt":

  • Großbuchstaben gegen Großbuchstaben,
  • Kleinbuchstaben gegen Kleinbuchstaben und
  • Ziffern gegen Ziffern.

Alle anderen Zeichen (z.B. Punkte, …) wurde nicht geändert und blieben an ihrer Stelle.

Jetzt habe ich drei englische Sätze, die Sinn machen! Obwohl manchen Wörter gemischt aus Klein- und Großbuchstaben bestehen.

Vielen Dank für Tipps.

Gruß

PS: ist mein erster Foreneintrag.

Re: Challenge  

  By: be on April 6, 2011, 11:14 p.m.

wo bzw. wie kann ich feststellen, was ich falsch mache?

Obwohl manche Wörter gemischt aus Klein- und Großbuchstaben bestehen.

Hallo Joerg,
ich habe mir Ihre Lösungen angeschaut – die Texte wären korrekt, wenn es uns in dieser Challenge nicht auch auf korrekte Groß-/Kleinschreibung ankommen würde.
In dieser Aufgabe muss man zuerst das Alphabet aufstellen, das laut Aufgabenstellung aus 62 Zeichen besteht – darin sind die Großbuchstaben, die Kleinbuchstaben und die Ziffern geordnet (Alphabete sind so definiert, dass sie jedes Zeichen genau einmal enthalten und in sich geordnet sind). Dann muss man den richtigen Verschiebewert finden, denn Caesar ist eine Verschiebe-Chiffre.
Damit ergibt sich eine Abbildung von Klartextalphabet auf Geheimtextalphabet, in der Großbuchstaben nicht immer auf einen Großbuchstaben abgebildet werden.
Ich hoffe, diese Hinweise helfen Ihnen erstmal weiter. Wenn nicht, dürfen Sie gerne weitere Fragen ins Forum stellen – wir posten gerne, ohne die Lösung direkt zu verraten.
MfG Be

Re: Challenge  

  By: friiky on April 7, 2011, 7:29 p.m.

Hallo,

ich hab meiner Meinung nach eine korrekte Rechtschreibung, Groß- und Kleinschreibung passt auch. Die Zahlen sind korrekt.

Die Homepage sieht das wohl anders.

Kann jemand helfen?

Grüße
Kalle


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