View Single Post
  #2  
Old 10-14-2010, 02:03 PM
kao kao is offline
Senior Member
 
Join Date: Sep 2007
Posts: 184
Default

dklasfv dfjak dadfsda. Can you tell me what the previous sentence mean?

It's virtually impossible to answer such questions without knowing context. Where did you get that text, what language it probably uses, what it is about, are these numbers or letters?

Your file consists of several parts:
3 bytes - purpose unknown
0x2EC byte - block of encrypted text? 1st and 2nd byte is the same, so is 3rd and 4th, 5th and 6th, etc, etc..
0x15 bytes - purpose unknown

Let's take a look at the big block. There are 108 different symbols, certain symbols are more common than others.

If text was compressed, we'd have more or less even distribution of all symbols and all 256 different symbols. We don't.

If it was a substitution cypher, the text was would have no more than 2*26 (english letters) +10 (numbers) +20 (punctuation, space, linebreaks, @%^&, etc..) = 82 different symbols. We have much more.

If it was sub/add/xor/not operation with a word/dword-sized key, we'd see some pattern (every 2nd/4th symbol is in certain range). We don't.

All symbols are less than 0x80 (most significant bit is 0). Some 7bit encoding?

Summary: if you have the software the produces (or uses) such text files, reverse the software and find out the algo. It's much faster than stare at the encrypted text and try to guess what algo was used there..
Reply With Quote