Abstract: A method for operating a locking system comprising an electronic key and an electronic lock and a central unit which in locking operation is used locally separately from the electronic key and the electronic lock, wherein in the method an external authorization code is generated by the central unit by means of an authorization code determination program, the external authorization code is transferred to the electronic key and the external authorization code is saved in a memory by the electronic key, wherein, on interaction of the electronic key with the electronic lock, the external authorization code is read out from the memory by the electronic lock and is checked by a processor of the electronic lock in that, using an internal authorization code determination program, the processor itself determines an internal authorization code and compares it with the external authorization code received by the electronic key and wherein, in the event of the determined internal authorization code being identical to the

Abstract: The invention relates to an electronic key (32) having at least two contacts (324, 325, 326) for the transmission of data and/or energy to an electronic lock (16). In accordance with the invention, the housing (321) of the electronic key (32) comprises an input device (33) for the entry of an authorization code (36). The invention also relates to an electronic closure system with an electronic key (32) and an electronic lock (16) as well as to a method for secure acquisition of an access authorization or for secure delivery of a key to at least one user (22) by means of an electronic lock (16) and at least one electronic key (32) carried by the user (22).