well ya it only finds Y for one particular x that u entered. and I am still working on the methodology to work with ECC in F2m. It is difficult to understand nd more mathimatical but its very useful for hardware implementation of ECC.
On Sun, Jan 25, 2009 at 11:18 PM, 龔士捷 Gung Shi Jie <[email protected]> wrote: > Many thanks~ > This method works for ECP curve. > > One thing interests me is, this finds a answer Y, but not all possible Y > for that X, right? > Can I find all Y, just curious. > > Also, how to find Y in EC2N field? > > > > > On Sat, Jan 24, 2009 at 6:41 PM, Nauman Abdullah < > [email protected]> wrote: > >> well ya how a message is encrypted by using a point. but some how I have >> managed to find a solution. and yes its possible to find y if the values >> of x are given. >> >> 1. in a finite field p select x, ( 0<x<p ) >> >> 2. Test x value to see if z=x^3+bx+c mod p is quadratic residue (q) >> applying Euler's criterion >> 3. Using Euler's criterion , find qr=z^[(p-1)/2] mod p >> (if qr =1 then it is quadratic residue modulo p) >> 4. Finally the formula to find y using formula z^[(p+1)/4]mod p. >> >> this is how u find y after selecting x. Correct if I am wrong. >> > -- Nauman Abdullah MS( IS -6 ) Military College Of Signals NUST 0300-6819189 --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the "Crypto++ Users" Google Group. To unsubscribe, send an email to [email protected]. More information about Crypto++ and this group is available at http://www.cryptopp.com. -~----------~----~----~----~------~----~------~--~---
