def encrypt(pb, msg):
#generate a prime
msg = int(msg)
r = pb.n - 1
while (math.gcd(r, pb.n) != 1):
r += 1
cipher = modOp.expoMod(r, pb.n, pb.n2)
cipher = cipher * (modOp.expoMod(pb.g, msg, pb.n2))
cipher = cipher % pb.n2
return cipher
def generateKeypair(bits, k=128):
p = rabinMiller.generatePrime(bits, k)
q = rabinMiller.generatePrime(bits, k)
while (p == q):
q = rabinMiller.generatePrime(bits, k)
n = p * q
phi = (p - 1) * (q - 1)
l = phi // math.gcd(p - 1, q - 1)
g = n + 1
n2 = n * n
while (math.gcd(modOp.expoMod(g, l, n2), n) != 1):
g += 1
#Inverse mod
mu = modOp.expoMod(L(modOp.expoMod(g, l, n2), n), phi - 1, n)
return PrivateKey(l, mu), PublicKey(n, g)
def millerTest(d,n): a = random.randint(3,n-2) p = modOp.expoMod(a,d,n) if(p==1 or p==n-1): return True; while(d!=n-1): p = (p*p)%n d *= 2 if(p == 1): return False if(p == n-1): return True return False
def homomorphicDivision(pb, c, p):
pdash = modOp.invMod(p, pb.n)
return modOp.expoMod(c, pdash, pb.n2)
def homomorphicMul(pb, c, p):
return modOp.expoMod(c, p, pb.n2)
def homomorphicAddP(pb, c, p):
return (c * modOp.expoMod(pb.g, p, pb.n2)) % pb.n2
def decrypt(pr, pb, c):
c = int(c)
m = L(modOp.expoMod(c, pr.l, pb.n2), pb.n) * pr.mu
m = m % pb.n
return m