Abstract: A method and system for confidential transmissions of documents over existing telephone communications lines is disclosed that generates encrypted documents suitable for reception by a facsimile machine. The encrypted document can be received by a facsimile device (60) at a distant location and decrypted by its intended recipient with the use of a unique encryptogram (38). The encrypted document can be recognized by existing optical character recognition systems and then modified to minimize the number of characters errors. The original text document is processed to create a unique character set prior to transmission and processed again at the receiving end to convert it into its original plain language format.

Abstract: A control device for programing information recorded upon a receiving part by an electrochemical marking head. In the main embodiment of the invention, the number recorded by the marking head is automatically sequenced after each marking cycle is completed.

Abstract: Apparatus for selectively marking the surface of a grounded conductive part using a known electrochemical marking process. The apparatus includes a writing head having a plurality of aligned digital modules mounted therein. Each module is made up of a series of electrodes that can be independently fired to create different electrical patterns. A dielectric stencil is placed between the part and the marking head that has grid lines cut therein which overlie each of the modules and serve to shape the electrical current passing through the stencil. By selectively firing the electrodes, different alpha-numeric characters can be recorded upon the receiving surface of the part without changing the stencil.