be described hereinafter the components and fundamental method steps involved in the authentication process will be explained with reference to fig2 which describes a tag 1 in accordance with iso standard 18000 6c or 18000 63 of course the tag 1 the protocol over the radio interface 2 and the reader 3 can also be formed in accordance with another standard providing the described authentication functionalities according to fig2 the tag 1 comprises four memory areas 6 9 protected to varying extent more specifically a first memory area 6 which is readable and writable arbitrarily via the radio interface 2 for example for application programs that run on a reader 3 a second memory area 7 which is readable via the radio interface 2 for receiving a unique tag specific identifier tid the memory area 7 is writable only during the manufacture of the tag 1 by a manufacturing process 10 which assigns the unambiguous tag identifiers tid and is otherwise write protected a third memory area 8 which can be written onto during the user specific initialisation of the tag 1 by an initialisation process is subsequently write protected and is then readable via the radio interface 2 the initialisation process 11 can be written onto with user specific operator specific data for example by a user for example a system operator who acquires a batch of tags 1 having different tag identifiers tid this data for example being an identifier of the operator or an index i which refers to one of many user specific keys k i stored in.