The invention provides a memory device including a memory substrate, an insulating layer, a shielding metal layer, a second dielectric layer and a second metal layer. A central checking centre allows users to verify the authenticity of a particular good such as a cigarette pack or carton via any convenient interface such as the internet or a cell phone. Modified ethylene-olefindiene polymers obtainable according to the above process or satisfying the equation: 2MS2Zis also described in which MS2, MV and % gel of the modified polymer are defined as defined above, X is 50, Y is 20, and Z is 40.