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:
Aug. 04, 1998
Filed:
Oct. 30, 1995
Stephanov Valerij, Steinhausen, CH;
Tompkin Wayne Robert, Ennetbaden, CH;
Staub Rene, Cham, CH;
Otto Carsten, Maintal, DE;
Landis & Gyr Technology Innovation AG, Zug, CH;
Abstract
A data carrier with an electronic circuit for storing and processing data is provided with an information strip with optically readable markings, and preferably a test field and an authentication feature. An optical interface, for example, can be provided for communication with a write/read device. The markings represent a digital signature. Testing of the authenticity of the data carrier can be done on the basis of the physical properties of the markings, the internal structure of the signature and/or the proof that a test number stored in the electronic circuit is equal to a number calculated from the signature according to a pre-determined function. The signature can also serve as a cryptographic key for encoding and decoding the data to be exchanged between the electronic circuit and the write/read device. The test field can be irreversibly modified when the data carrier is used. The write/read device contains an optical reading head for machine reading the markings and is optionally connected to a data processing point by means of a communication network.