Alive

Just another crypto keygenme and delphi ****.

Only valid solution is a keygen.

Luck,

HMX0101 // 10-04-2011

alivekgme-hmx.rar

Is this ElGamal Signature Scheme? It looks like it.

Anyway, attempting to solve DLP to get the private key

gives me: "Can't solve that sh*t!"

Never solved ElGamal (or DLP) before, so I'm a newbie in that area.

I've identified all the FGInt calls and stuff and know what it's doing,

but don't know how to reverse it.

First thought was to generate first 2 parts of serial randomly and

then solve 9F76B9617C4B04782B89 ^ X mod E50D80BB9284DF3F23D3 = Y to

get the 3rd part, where X is the 3rd part of serial and Y is calculated

based on 1st and 2nd part of serial and name. But solving DLP every time is unfeasible.

-- EDIT --

Been trying to get the private key by solving the DLP (using another DLP solver)

for 3 hours now and still nothing. I must be doing something wrong.

Guess I'm not the only one having difficulties with this one, considering it's still unsolved.

-- EDIT --

If this is indeed ElGamal, then am I correct with the following?

Y = G ^ X mod P, where G,P,Y are public keys and X is the private key.

Y = E17D4BC428ED77A25829

G = 9F76B9617C4B04782B89

P = E50D80BB9284DF3F23D3

Edited June 1, 201114 yr by Saduff

You're correct, those are the values for P,G,Y.

About the DLP solving time, I would recommend you to use a solver based on Index Calculus method.

Thanks, I found a calculator that solved the DLP in 0.5 seconds.

Now let's see if I can keygen this thing.

-- EDIT --

Now I don't understand what the 3rd part of the serial (last 20 chars) has to be.

I think that the first 2 parts of the serial are the signature (r, s).

The 3rd part of the serial is used only here: G ^ serial[3] mod P, so I thought that

it has to be MD5(name), but that can't be, since MD5 is 32 chars long.

So I tried using MD5(name) mod P as the 3rd part of the serial, but that didn't work.

Edited June 1, 201114 yr by Saduff

The third part of the serial is part of the signature.

Difficulty of the challenge is to find out what the third part should be

Thanks for the keygenme!

I hope my keygen works well.

keygen.rar

Edited June 11, 201114 yr by Soul

Nice work Soul, ATM you're the only one that solved it

And I don't know why if Its so simple

Thanks, I found a calculator that solved the DLP in 0.5 seconds.

Now let's see if I can keygen this thing.

Care to share that tool, or give me/us a link for it?

I have been looking for a dlp solver using the index calculus method for a while now.

Maybe I'm just a bad googler

- rdbnhoax

I used Magma Calculator:

http://magma.maths.usyd.edu.au/calc/

Used this script:

p := 1081671008419063856571347;
K := GF(p);
g := K ! 753046344671602713045897;
y := K ! 1064843761188532526405673;
x := Log(g, y);
x;

Don't know if it uses the index calculus method, but it solved the DLP very fast, while other solvers failed.

Thank you Saduff

- rdbnhoax

yeah, really nice scheme

thanks to KKR, for informing me, that it's a special signature scheme, so could be solved more effective way, rather than runtime DLP solving for each signature. So I wrote the equation with pen and got the result

for those, who are interested how to get signing algorithm without searching for some common schemes:

maybe I'll solve this kgm soon, once i get bored.

Edited July 6, 201114 yr by qpt^J

I got freak'd out by the serial decoding algo

May be if I get bored some time, I'll touch it again

way to go qpt do it !!

Okie.. I got bored & I touched it again.. This time I recoded ya Serial Decoding stuff in Delphi.

Here it is.

http://pastebin.com/Gqyw9DLz

Accoriding to my logic.. It should be reversed as Under, but it isn't working.

http://pastebin.com/Tw30Vtqv

Any 1 else having this prob ?

Edited July 13, 201114 yr by KKR_WE_RULE

cool kgm really thx kkr for that hint

Keygen.rar

Nice job mate, wasn't that hard, huh?

Btw, my intention was to use 'FUN' as first 3 chars... I didn't thought about other possible words

for me, it was hard, yeah

especially that Lexicographical order part, because there wasnt any good explaination about it on inet, only by guessing i found how it works

and found that 'KEY' part by guessing too

That transformation part kick'd my *** Real thanx goes to Dcoder__. I couldn't identify the algo there.

Ok.. now it can be made public.. Its BWT De_Transform() that used there. Need to use BWT_Transform() to reverse it

@qpt^J : Great work as always Congratz

@HMX : I'll still write a soln, coz last time I tried I had some probs with the BWT_Transform(). It was hard for me.. but I have gotta admit, it taught me a great deal of stuff. Thanx a bunch

I'm years late as always D:

I'm including the modified ElGamal signature's paper, my notes (in italian, sorry), the (probable) original Delphi BWT source used in the KeygenMe, a sorta equivalent implementation in Python found on the net and most importantly my keygen in Python. Uses Z3Py to retrieve the first three letters of the serial
Also included a version with the precalculated string in case you don't want to install and configure Z3Py. The other dependencies are standard Python 2.7 modules.

EDIT: finally added to my KGCollection. Relevant sources: BWT, keygen.

Alive.7z

Edited June 13, 20169 yr by SmilingWolf