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:
Jan. 10, 1989
Filed:
Oct. 28, 1985
James L Massey, Zurich, CH;
Rainer A Rueppel, Wetzikon, CH;
Borer Electronics AG, Biberist, CH;
Abstract
A converter or running-key for generator producing pseudo-random sequences under the supervision of a secret or confidential key or code is substantially formed by a combination device containing a memory circuit and a feedback circuit. Periodic digital sequences are summed in an adder circuit, and the thus obtained composite digital sequence is separated in a divider circuit. A part of this composite digital sequence is used as a digital feedback sequence which is fed to an input of the same adder circuit through the feedback circuit comprising an auxiliary digital memory device or storage and an auxiliary logic circuit. In this manner, the desired memory and feedback is achieved which results in more complicated or complex pseudo-random sequences. In an advantageous exemplary embodiment, a substitution block is inserted as the auxiliary digital memory device or storage. This substitution block can be implemented by a commercially available read-and-write memory (RAM).