| 摘要 |
A security system and, in one particular embodiment, security systems for protection of computer software against unauthorised access. One specific application for this invention is to inhibit the running of computer programs whilst still permitting the software to be copied. A further specific application of the invention is in the production of encoded documents, labels and tags which cannot be read but again, can be copied. In one aspect the invention comprises a system to inhibit unauthorised access to data comprising; a) output means (28) to transpose two or more components of an element of said data in accordance with a preselected algorithm, and thus produce an encoded element, and, b) decoding means (29-31) to rearrange said encoded element, thereby recreating the element of said data, characterised in that, the output means (28) comprise at least one microprocessor programmed with said algorithm and means for displaying the encoded element in visible form, and the decoding means comprise at least one optical element (29) capable of rearranging said encoded element. |
