new_contents: import binascii, hashlib, hmac, os, time
  
  def scramble_with_kdf(passw, salt, iters):
      return hashlib.pbkdf2_hmac('sha256', passw, salt, iters, 32)
  
  def scramble_with_sha256(passw, salt, iters):
      passw = salt + passw
      for i in range(iters):
          passw = hashlib.sha256(passw).digest()
      return passw
  
  def scramble_with_hmac(passw, salt, iters):
      hmac_obj = hmac.new(salt, passw, hashlib.sha256)
      for i in range(iters):
          hmac_obj.update(passw)
      return hmac_obj.digest()
  
  iters = 10000000
  passw = "hello world".encode()
  salt = os.urandom(256)
  
  start1 = time.time()
  print(binascii.hexlify(scramble_with_kdf(passw, salt, iters)))
  end1 = time.time()
  
  start2 = time.time()
  print(binascii.hexlify(scramble_with_sha256(passw, salt, iters)))
  end2 = time.time()
  
  start3 = time.time()
  print(binascii.hexlify(scramble_with_hmac(passw, salt, iters)))
  end3 = time.time()
  
  
  print("scramble_with_kdf:\t{}".format(end1 - start1))
  print("scramble_with_sha256:\t{}".format(end2 - start2))
  print("scramble_with_hmac:\t{}".format(end3 - start3))
  
subject: Add timing test of password scrambling with pbkdf2, sha-256 and hmac(sha-256)