The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 21, 1980
Filed:
Apr. 28, 1978
Barrie O Morgan, Dallas, TX (US);
Merlon B Carter, Richardson, TX (US);
Datotek, Inc., Dallas, TX (US);
Abstract
The specification discloses a portable cryptographic device, adapted to be hand-held through solid state electronics, which possesses the capability for enciphering and deciphering plain text. The housing of the device has a keyboard for the input of plain text or cipher text, including numeric characters and control signals and, further, has a display for displaying the inputs. Circuitry within the device is responsive to the inputs and controls the display. Additional circuitry enciphers or deciphers the inputs and substitutes the resulting text into the display. The device incorporates a random code generator for generating a randomized message key which, together with the keyboard inputs, initiates and generates a long sequence of randomized letters for enciphering purposes. In a deciphering mode, a predetermined message key may be entered to set the random code generator at a point to generate the originally entered plain text. Also, a basic key composed of multiple segments fully initializes the random code generator such that more than one device could be used to encipher and decipher text. Similarly, by using different segments of the basic key, varying levels of security can be obtained. Test circuitry is also provided to insure maintenance of the proper key variables and proper operation of the device.