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:
Nov. 05, 2002
Filed:
Apr. 19, 1999
Sung-Ming Yen, Taipei, TW;
Pao-Yu Kuo, Taipei, TW;
Institute For Information Industry, Taipei, TW;
Abstract
A cryptographic checksum apparatus is disclosed. This apparatus includes a keystream generator configured to generate a secret keystream according to a common secret key. The apparatus also includes a postfix circuit configured to augment postfix bits after an original message. Further, a demultiplexer is used to direct the postfixed message to one of the output terminals under the control of the secret keystream. A first mixer is connected to one output terminal of the demultiplexer, and a second mixer is connected to the other output terminal of the demultiplexer. Moreover, a first compression circuit is used to receive an output of the first mixer, wherein content of the first compression circuit is used as the first part of the checksum output. Similarly, a second compression circuit is used to receive an output of the second mixer, wherein content of the second compression circuit is used as the second part of the checksum output. Finally, a first transmission gate is connected to the second compression circuit, whose output bit is then transferred to the first mixer through the first transmission gate under control of the postfixed message bit. A second transmission gate is connected to the first compression circuit, whose output bit is then transferred to the second mixer through the second transmission gate under control of the postfixed message bit.