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. 01, 2002
Filed:
Mar. 19, 1996
Ryota Akiyama, Kawasaki, JP;
Akio Munakata, Kawasaki, JP;
Yuzuru Koga, Kawasaki, JP;
Masayuki Ishizaki, Kawasaki, JP;
Makoto Yoshioka, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A random-number generator generates first and second title keys on the basis of random numbers. A first DES encryption circuit for the title encrypts input data with the first title key. Initial values of this item of input data are a data identifier (ID) and program clock reference (PCR) that are extracted from a packet header. After completing the encryption of the initial values, a result of an encryption by a second DES encryption circuit for title serves as the input data for the first DES encryption circuit for title. The second DES encryption circuit for title encrypts a value of result of the encryption by the first DES encryption circuit for title with the second title key. An exclusive OR circuit outputs an exclusive OR of the data stored in the packet and a value of result of the encryption by the second DES encryption circuit for title. This exclusive OR turns out encrypted data.