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:
Apr. 22, 1986
Filed:
May. 04, 1983
Hendrik Vrielink, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
The unauthorized reading of program words stored in a memory of a dating processing system is counteracted by supplying the unauthorized reader with nuisance data from a data source instead of program words from the memory. In order to determine whether the memory is being read by an unauthorized reader or by a data processor unit of the system for the execution of the program, use is made of the sequence in which the data processor unit reads the program words from the memory. This sequence deviates from the sequence in which the program words are stored in the memory. Additional information is added to each program word stored in the memory, said additional information containing an indication of a subsequent program word to be read by the data processor unit. On the basis of this additional information it is tested whether the memory is being read in the sequence determined by the data processor, for the execution of the program, or in some other sequence by an unauthorized reader who does not know the sequence determined by the data processor unit.