Numbers and dates encrypted into patterns make up a recurring element in Mayer H.’s architecture, drawings, and objects. He is especially interested in the data protection methods and preprints used by banks to encrypt pass codes or PIN numbers in letters to customers. Data protection patterns guarantee that no one but the recipient can see the information. His research led Mayer H. to the oldest source of these forms, which date back to 1913, and over the years he has amassed a collection of around four hundred different patterns. This large size publication features one hundred different preprints, which form the basis for many of his buildings, drawings, sculptures, and design objects.