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:
Dec. 25, 2007
Filed:
Jun. 02, 2005
André Kudelski, Lutry, CH;
André Kudelski, Lutry, CH;
Nagracard S.A., Cheseaux-sur-Lausanne, CH;
Abstract
The aim of this invention is to improve in an optimal way the security of smart cards to prevent the fraudulent control of a cryptographic processor(s) by means of external signals that interfere with the normal development of the tasks of a processor(s). This aim is reached by a component IC of a security module comprising at least two processors CPU A, CPU B each connected to program memories ROM A, ROM B, to non-volatile programmable and erasable memories (EEPROM) EEPROM A, EEPROM B containing the data and random access memories (RAM) RAM A, RAM B that serve as temporary data storage during processing, the first processor CPU A having an interface bus toward an exterior of the component IC, characterized in that the second processor CPU B is connected to the first processor CPU A through an exchange memory DPR, the non-volatile programmable and erasable memory EEPROM A of the first processor CPU A having read-only access R for said first processor CPU A, the second processor CPU B having read and write access R/W on said non-volatile programmable and erasable memory EEPROM A of the first processor CPU A.