Abstract: The present invention concerns a locking system (31) for an entry door to a security enclosure arranged in an environment. This locking system includes a mechanism (33) able to command, in response to an instruction, the locking or unlocking of the entry door, storage means (43) able to contain reference data (X3) relating to a parameter (X) linked to the environment, and depending on the environment, and a processing unit (37) able to receive the reference data and parameter measurement data (X2) and, in response, to supply the command instruction. This arrangement gives the locking system autonomous control of the development of a parameter and centralised control of the locking and/or unlocking. The storage means (43) can be arranged to give the locking system the faculty of intelligent interpretation of the events and phenomena occuring during its daily operation.