CRYPTO - Cryptography


Your task is to work as a cryptographer for some time, the reason is ...

Blue Mary has set a problem using English. Since the problem is too easy and it will be boring when solving it, she has deleted all the whitespaces and punctuations in the original problem description, and lowercased all the capital Latin letters. Then, she randomly chose a permutation of the English lowercase letter alphabet, and then used the corresponding letters in place of the letters in the original text.

The encrypted text can be downloaded here.

There is no example for this problem.

Some tricky test cases were added on Nov. 25th, 2007 and the time limit has been changed. Programs have been rejudged and some "accepted" solutions got Wrong Answer. However, this problem can still be solved by quite clean code with length less than 1KB.


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Damian Straszak: 2012-05-19 08:05:12

Worst problem ever, the description is full of ambiguities.

Andrew: 2012-05-09 11:17:44

Does frequency analysis work, or do you just have to brute force it?

PetarV: 2012-05-06 09:55:35

Agree completely. I wasted a lot of time trying to figure out the deciphered text completely right.
Finally AC after 3 pages of submissions :)

Last edit: 2012-05-06 09:55:51
Goran Zuzic: 2012-05-05 16:01:10

Worst. Problem. Ever.
Really, don't bother after you've deciphered the text file :)

gawry: 2012-05-01 19:29:17

Evil indeed!

blashyrkh: 2011-08-29 19:40:41

@xilinx: EVIL you are! Thanks for problem :)

Alex Anderson: 2011-04-07 05:45:25

I had fun decrypting the message.
EDIT: If the problem is so easy, how can there be tricky test cases?

Last edit: 2011-03-03 04:01:18
Archeleus: 2011-04-07 05:45:25

Kind of tough question. The problem with this is that there are 26! probable key streams. I'll try this when I'm bored.

abhijith reddy d: 2011-04-07 05:45:25

Insane ! .. Definitely not as easy as it seems.


Added by:Fudan University Problem Setters
Date:2007-11-03
Time limit:2s
Source limit:50000B
Memory limit:1536MB
Cluster: Cube (Intel G860)
Languages:All except: C99 ERL GOSU JS-RHINO
Resource:Sadly, the ability to make a simple problem difficult to understand is seldom considered a talent.