This is the international
reverse engineering challenge conducted by U.S based security
company. The purpose of this challenge is to evaluate the
effectiveness of software protections. The results of this effort is
used to improve the protection measures used in the softwares.
The contest is carried out in 3 phases where first and third phase
involved breaking the protection of custom programs by using reverse
engineering. The interesting part of this reversing challenge is the
usage of floating point computations.
For more details on various phases and the rules, visit the
Hacker Challenge website.
Hacker Reversing Challenge Phase I
Phase I of the challenge involved
breaking the protection of Windows binary program that produces
certain output. Goal of this challenge is to achieve following
objectives
Reverse engineer the mathematical formula that results in
the value "10.9319" of the output.
Remove the limitation on an input data field of the code so
that values greater than 210.5 are treated the same as values
less than 210.5.
Phase III of this reversing
challenge involved the similar program but it was more difficult
than the program at phase I. It also had floating point operations,
but protections mechanism were implemented in much better way
compared. Also some lesser known
anti debugging techniques were used.
Goal of this challenge is to achieve
following objectives...
Reverse engineer the mathematical formula that results in the
value "-59.0079" of the output.
Remove the limitation on an input data field of the code so that
values of 200 or greater are treated the same as values less than
200.
I have written detailed description on the solution which will help
you in understanding and solving the problem. You can find it on
Hacker Reversing Challenge Phase
III page.
All together it was interesting challenge worth trying out
especially for the reversers who have crossed beginner level. If you
have already tried it and left it in the middle, then you can look at
the detailed solution(follow the above mentioned links for respective
challenges) and finish it off..!
