A method for managing a conference between two or more parties comprises an identity based authenticated key exchange between a conference management element and each of the two or more parties seeking to participate in the conference. At least one nanostructured layer comprising an organic material or an organic-inorganic hybrid material is applied to the alternating layers. The method further includes embedding the watermark image and the matrix code symbol in the host image at non-overlapping positions in the host image. Further, the drum may be a polymeric drum including an interior surface formed by a plurality of complementary molded helical polymeric sections joined along a helical seam. When the display device displays the graphic user interface, if an input device receives a shift command inputted by a user, the display controlling module controls the display device to move at least a portion of the option objects on the graphic user interface toward a same side and to change position or content of at least one reference indicator.