+eval = True
+count = 0
+
+""""
+while count < 1000 and eval :
+ lx = randint(500,1000)
+ x = [randint(0,1) for _ in xrange(lx)]
+ lm = randint(lx/10,lx/2)
+ message = [randint(0,1) for _ in xrange(lm)]
+ (x_b,y,H_hat) = stc(x,message)
+ eval = equiv(message, prod(H_hat,len(message),y))
+ if not (eval):
+ print x
+ print message
+
+ count +=1
+ if count % 100 == 0 :
+ print count
+
+print nbdif(x_b,y),count
+"""