code: def generate_secured_key(value,
          key_nonce_separator='.',
          nonce_length=4,
          base=BASE62):
      
      if not isinstance(value, (int, long)):
          raise ValueError()
  
      posix_time = int(time.mktime(datetime.datetime.now().timetuple()))
      nonce = hashlib.md5(str(posix_time)).hexdigest()[:nonce_length]
      key = int_to_key(value, base=base)
      return key, nonce, '%s%s%s' % (key, key_nonce_separator, nonce)
docs: Generate a secured key composed of the integer value encoded in Base62
      and a nonce.
  
      @param value: an integer value.
  
      @param key_nonce_separator: the character that is used to separate the
          key and the nonce to form the secured key.
  
      @param nonce_length: the number of characters to compose the nonce.
  
      @param base: a sequence of characters that is used to encode the
             integer value.
  
      @return: a tuple ``(key, nonce, secured_key)``:
          * ``key``: string representation of the integer value in Base62.
          * ``nonce``: "number used once", a pseudo-random number to
            ensure that the key cannot be reused in replay attacks.
          * ``secured_key``: a string composed of the key concatenated with
            the nonce.