[KeygenMe] KeygenMe #16

[Saduff]

Since my last KGM was too simple, then here's another one. This one should be harder.

KeygenMe16.zip

[MA1201]

Name : k‰ÔØÿv|EüPÔ£w«UX£‹:"§‰¦ùX

Serial : C29FE4713F31B48A02C3E58D803745EE4A9BFE01976B97707975ED312F751DF2F4E4CC307EEC571722F40454A1595E24B699518878163C256B16AEDF11A65B82

i know it's lame, just for lulz

hope it works..

[Saduff]

Unfortunately, doesn't work. Name should be:

k‰ŌŲ˙v|EüPŌ£w«UX£‹:"§‰¦łX

Name you gave:

k‰ÔØÿv|EüPÔ£w«UX£‹:"§‰¦ùX

[MA1201]

plz check again, the name you provided doesn't work, the name & serial combination i posted works

[Saduff]

Hmm, well, on my machine (XP SP3 x86), the name I provided works, but not the one you provided.

Edited August 15, 2011 by Saduff

[KKR_WE_RULE]

The serial provided by Ma1201 works but the you(Saduff) provided aint working

[HMX0101]

I know what's going on here, but I'm not sure if the other value from public-key pair (since you're using it backwards) can be retrieved.

[qpt^J]

we need to get G from equation U = G^L (mod N^2) where

U = 37F9C8007A2E278F9ED43223657938A693752710D030A71A1FA7D2380FE7BE4CB6E3DFFE13ADB30967E4A7443046E6ECCB75B11A3D932E7F9AA44E02FCA166D7

L = 203CDDC2D7EC7FE5CB7352EC3C3DD9616160E54E3B2A7EE3FB039511466D6CD0

N^2 = 40F45E9696A53EFB3F7E5A77111E1702826D8734C5E69226DEAD774BE70D7F974F2A0F8BC46107269F7193B4093BBB2ACF0ACA5D2FA08AE1BE29E5BFB4816329

if i didnt done any mistake anywhere..

is there any known algo to compute this? :S

and i guess homomorphism won't help here too much. and it's understandable why you've used decryption, instead of encryption. but even if you use encryption there, i think solving 512 bit DL problem wont be that easy even for such field Z_N^2

EDIT:

The problem is:

U = 1 / [L(g^l mod n^2)]

L(x) = (x-1)/n

As I said, I think its not possible to get G..

the symbol "U" you wrote there is "myu" from greek alphabet i think

and it's possible to compute the second algo you wrote there.. the only problem is so-called DCRA
/>http://en.wikipedia.org/wiki/Decisional_composite_residuosity_assumption

Edited August 17, 2011 by qpt^J

[HMX0101]

The problem is:

U = 1 / [L(g^l mod n^2)]

L(x) = (x-1)/n

As I said, I think its not possible to get G..

[Saduff]

Damn, I was afraid it might not be possible to get G.

My attempts to get it failed, but I was hoping it's just me and

the KGM was already ready, so I published it anyway.

Well, in that case, should I publish G, so you could gen it?

[qpt^J]

i think theres no fun from that, and maybe some ppl are more smarter here and know how to defeat it, so i guess this cme will not be solved for a quite while if not forever

[_sb_]

The Ideal would be to factor U, That would take a weak or more, But If one can factor N^2 then I think it would be easier to solve this.

[Saduff]

If numbers are too big, I could recompile with smaller numbers if necessary...

[_sb_]

I will not be near a proper not-browser only computer for a while, I just thought that you had given some thought when you compiled this one and that there would actually be weaknesses on your routine, unfortunantly that was not true it seems.

[HMX0101]

You don't need to factor N^2, since N=256bits and N = p*q, N^2 = (p^2) * (q^2).

Reducing numbers won't do any difference..

[ChOoKi]

Damn, I was afraid it might not be possible to get G.

My attempts to get it failed, but I was hoping it's just me and

the KGM was already ready, so I published it anyway.

For what it's worth

sol.zip