I. 201. The Cardan grille is a simple grid to write and read hidden messages. The hidden text in the square pattern can be revealed only if the grid is positioned above the text, then letters are read through the holes in the usual order from left to right and top to bottom. By rotating the appropriate grid by 90o (in this example, counterclockwise), one can repeat the procedure, and after 4 passes each letter of the square is read exactly once. The example text refers to a literary work in which Cardan grille also plays role.
Make a presentation to illustrate the use of the Cardan grille. Given a 6×6 grille, create an animation that shows how to make the square of letters, then how to use the grille to read the hidden message.
The presentation (i201.ppt, i201.odp, ...) together with a short documentation (i201.txt, i201.pdf, ...) should be submitted, also containing the name and version number of the software applied.
Deadline expired on 15 January 2009.