US Patent 7999659 Method for access control

A method for access control to at least one memory area of a passive and/or backscatter-based transponder is provided. In the method for access control, depending on an identification selection criterion, a first or at least one second identification within the transponder is activated, the activated identification upon an appropriate request by reader unit is transmitted to said unit, the at least one memory area of the transponder is divided into memory blocks with a settable size, access control information is assigned to a respective memory block, and read and/or write access to a specific memory block is released or blocked depending on the associated access control information and the identification selection criterion.