Ecc.rb

def modInverse (var,n)
    lm = 1
    hm = 0
    low = var % n
    high = n
    while low > 1 do
        ratio = high/low
        nm, enew = hm-lm*ratio, high-low*ratio
        lm, low, hm, high = nm, enew, lm, low
    end
    return nm % n
end

def ECadd(a,b)
    lamAdd = ((b[1]-a[1]) * modInverse(b[0]-a[0],$provePrimeNumber)) % $provePrimeNumber
    x = (lamAdd*lamAdd-a[0]-b[0]) % $provePrimeNumber
    y = (lamAdd*(a[0]-x)-a[1]) % $provePrimeNumber
    return [x,y]
end

def ECdouble(a) 
    lam = ((3*a[0]*a[0] * modInverse((2*a[1]),$provePrimeNumber)) % $provePrimeNumber
    x = (lam*lam-2*a[0]) % $provePrimeNumber
    y = (lam*(a[0]-x)-a[1]) % $provePrimeNumber
    return [x,y]
end

def EccMultiply(genPoint,scalarHex)
    scalarBin = dectobin(scalarHex)
    q=genPoint
    for i in 1..scalarBin.length-1
        q=ECdouble(q) 
        puts "DUB", q[0]
        if scalarBin[i] == '1'
            q=ECadd(q,genPoint)
            puts "ADD", q[0]
        end
    end
    return [q]
end