Secured method for controlling the opening of locking devices by means of messages using symmetric encryption

摘要

The method involves generating a digital data by an administrative site (10), and the digital data is encoded in a symmetrical method. The digital data is provided in a field. The digital data is encoded by an encoding algorithm and with an encoding key. A message (DKE) containing an encrypted field is generated. The message is transmitted to a secure module (20) via a communication network towards a portable device such as cell phone. The key is upgraded, and another key is recomputed based on an identifier of a received variation function. The latter key is updated with a secure key.