• 标 题:转贴:Ivanopulo说CloneCD用的是椭圆曲线密码算法 (1千字)
  • 作 者:guest
  • 时 间:2000-7-11 0:13:29
  • 链 接:http://bbs.pediy.com

Here is a Ivanopulo's .nfo part about asprotect:

"For those who's interested in this program's protection mechanism -
here's the info:

Main keycheck routine is implemented as Nyberg-Rueppel signature
scheme for Elliptic Curves defined over F2^m polynomial field. This
makes writing a keymaker for CloneCD impossible. (so don't believe if
someone says he managed to keygen it)

The curve used has 242 bit prime order
1026DD85081B82314691CED9BBEC30547840E4BF72D8B5E0D258442BBCD31

I have the data for field polynomial written down somewhere on my HD,
but atm I have no time to search for it, so sorry (the only thing I
can recall it was polynomial of 272 or 271 degree)

By the way, the curve used in CloneCD is the SAME curve defined over
the SAME polynomial field as used by WinRAR. Heh, I wonder where did
those guys find it and the library they used for implementing ECC. I
know only one library that implements ECC - Miracl, but it has only
Fp implementation. Maybe they bought the library from certicom...
anyway, if you have that library and don't mind to send it to me -
please do it. I had to dig into all this ECC implementation looking
at disassembled code. Not the most pleasant occupation I had in life
:)

And the second level of protection in this program is implemented
using ASProtect. Alex Solodovnikov did very good job on this
protector (hi Alex) but yet it is possible to defeat it. The point is
that ASProtect encrypts some program routines (in case of CloneCD
registration info/program settings saving functions) and decrypts
them with the password provided in the user's registration info
(encrypted there). But fortunatelly I was able to grab one of the
'stolen' keys and after it was decrypted in memory I knew ASProtect
password. Hehe, it's 'Suck me!' by the way.

Okay, enuff talking... use it and enjoy =)"