Python for Reverse Engineering

James Sapara james at frontlogic.com
Wed Nov 10 22:43:31 CET 2004


Here's some statistical data from the set of keys I posted. I didn't do 
any pattern matching, but I think this shows that the keys are fairly 
random in composition. I have also included stats for a much larger set 
of keys. I noticed in the set of 100 that I didn't get any keys in the 
fourth deviation, so I wanted to make sure such keys do exist. If you 
can think of any other stats from the ord values of character I could do 
that as well. Since I know the algo I also know that the sets of 5 are 
only for readability.

Pattern matching based on Number/Alpha would probably show that over a 
large set of keys it matchs the ratio of numbers to alpha's used in the 
keys. You could do binary comparisons of the N,A's and try to find 
common patterns.

Min/Max ord values ('0', 48) ('Z', 90)
Min Sum/Max Sum/Average Sum 1200 2250 1725
Average value of byte 69
Number of Keys 100
Average sum of keys 1745
Range of Key Sums 1564 to 1894
STD range -3 to 3
Squard Root of Key Sums 79.1896457878

Min/Max ord values ('0', 48) ('Z', 90)
Min Sum/Max Sum/Average Sum 1200 2250 1725
Average value of byte 69
Number of Keys 10000
Average sum of keys 1753
Range of Key Sums 1460 to 1977
STD range -4 to 4
Squard Root of Key Sums 75.0266619276

James

****** wrote:

> I'm not a cryptanalysis guy, is there any value in doing this to the 
> strings, uploading this data to a DB and then searching for patterns:
>
> ;5V6XBTV6N65H7J3WWTWQ6H74B;5V6XB;TV6N6;5H7J3;WWTWQ;6H74B;NANAAAANANNANANAAAAANANNA;NANAA;AANAN;NANAN;AAAAA;NANNA;[53, 
> 86, 54, 88, 66, 84, 86, 54, 78, 54, 53, 72, 55, 74, 51, 87, 87, 84, 
> 87, 81, 54, 72, 55, 52, 66];[53, 86, 54, 88, 66];[84, 86, 54, 78, 
> 54];[53, 72, 55, 74, 51];[87, 87, 84, 87, 81];[54, 72, 55, 52, 
> 66];1733;347;356;305;426;299
> ;CBPPCLTJ5X1S8ZS5LVBZYRFVW;CBPPC;LTJ5X;1S8ZS;5LVBZ;YRFVW;AAAAAAAANANANAANAAAAAAAAA;AAAAA;AAANA;NANAA;NAAAA;AAAAA;[67, 
> 66, 80, 80, 67, 76, 84, 74, 53, 88, 49, 83, 56, 90, 83, 53, 76, 86, 
> 66, 90, 89, 82, 70, 86, 87];[67, 66, 80, 80, 67];[76, 84, 74, 53, 
> 88];[49, 83, 56, 90, 83];[53, 76, 86, 66, 90];[89, 82, 70, 86, 
> 87];1881;360;375;361;371;414
> ;QJCT6VXYLT2S9QZSQ02GMJD9S;QJCT6;VXYLT;2S9QZ;SQ02G;MJD9S;AAAANAAAAANANAAAANAAAANA;AAAAN;AAAAA;NANAA;AANAA;AANA;[81, 
> 74, 67, 84, 54, 86, 88, 89, 76, 84, 50, 83, 57, 81, 90, 83, 81, 79, 
> 50, 71, 77, 74, 68, 57, 83];[81, 74, 67, 84, 54];[86, 88, 89, 76, 
> 84];[50, 83, 57, 81, 90];[83, 81, 79, 50, 71];[77, 74, 68, 57, 
> 83];1867;360;423;361;364;359
>
>


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James Sapara
Software Architect

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