Cracking the RSA cyprtosystem time

rsacrack.py

import gmpy, time, random, math

def genprime(bits):
    p=1
    while(gmpy.is_prime(p)==0):
        p = random.randrange(math.pow(2,bits-1),math.pow(2,bits))
    return p

BITS=20
found=False
p=genprime(BITS)
q=genprime(BITS)
n=p*q
cnt=2
s_time=time.time()
while not found:
    found=(n%cnt==0)
    cnt+=1
e_time=time.time()-s_time
if found:
    print "%d can be devided by %d"%(n, cnt-1)
    print "It took %d ms "%(cnt-1)