Patents by Inventor Stefan Wallstab

Stefan Wallstab has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7739520
    Abstract: The invention relates to a data processing device with a functionally programmable logic circuit and a programming interface. An authorization control unit is provided, which protects the programming interface against an unauthorized access. This enables the functions of a semiconductor module to be changed in a customer-specific manner while preventing unauthorized entities from subsequently changing the functionality.
    Type: Grant
    Filed: August 11, 2003
    Date of Patent: June 15, 2010
    Assignee: Infineon Technologies AG
    Inventors: Helmut Horvat, Jan Otterstedt, Stefan Wallstab
  • Patent number: 7122899
    Abstract: An ohmic resistance is present between two parts of a conductor layer so that the size of the ohmic resistance can be ascertained and/or a semiconductor region is present in or on a layer forming the dielectric. The conductor layer is structured into a gate contact, a source contact, and a drain contact so that a transistor function or switching function is possible in the semiconductor region. Such a configuration allows an attempt to analyze the circuit integrated in the chip to be detected.
    Type: Grant
    Filed: April 26, 2002
    Date of Patent: October 17, 2006
    Assignee: Infineon Technologies AG
    Inventors: Bernhard Lippmann, Stefan Wallstab, Günter Schmid, Rainer Leuschner
  • Patent number: 7036018
    Abstract: An integrated security circuit, for example, a microcontroller for smart cards, includes a function unit executing a security function. A control device determines the number of executions of the security function per unit of time. The continued execution of the security function is blocked when a threshold value is exceeded. For such a purpose, an analog timekeeper incorporating a charge storage device is preferably provided that measures the elapsing time even with the supply potential disconnected. A usage counter is updated whenever the security function is called. The security circuit offers increased protection against statistical attacks. The complexity involved in the implementation is justifiably low. The security circuit is compatible with the existing system.
    Type: Grant
    Filed: July 19, 2002
    Date of Patent: April 25, 2006
    Assignee: Infineon Technologies AG
    Inventors: Helmut Horvat, Stefan Wallstab
  • Patent number: 6933742
    Abstract: A circuit for monitoring an entry into a test mode of a chip circuit has a fusible link which can be fired via a firing transistor. A flipflop, which permits access to the test mode, is set by a resulting voltage drop, with the aid of an edge detector. The number of times the test mode has been accessed can be detected from the number of fired fusible links.
    Type: Grant
    Filed: July 18, 2002
    Date of Patent: August 23, 2005
    Assignee: Infineon Technologies AG
    Inventor: Stefan Wallstab
  • Publication number: 20040143747
    Abstract: In a digital circuit comprising an asynchronous circuit, the supply voltage of the asynchronous circuit is varied by means of a random voltage jitter. The random variation of the supply voltage causes a time jitter in the processing of the individual operations within the asynchronous circuit, whereby an artificial synchronizing of individual measurements in side channel attacks is prevented.
    Type: Application
    Filed: December 11, 2003
    Publication date: July 22, 2004
    Applicant: Infineon Technologies AG
    Inventors: Gernot Eckstein, Christian Aumueller, Stefan Wallstab
  • Publication number: 20040034789
    Abstract: The invention relates to a data processing device with a functionally programmable logic circuit and a programming interface. An authorization control unit is provided, which protects the programming interface against an unauthorized access. This enables the functions of a semiconductor module to be changed in a customer-specific manner while preventing unauthorized entities from subsequently changing the functionality.
    Type: Application
    Filed: August 11, 2003
    Publication date: February 19, 2004
    Inventors: Helmut Horvat, Jan Otterstedt, Stefan Wallstab
  • Patent number: 6601202
    Abstract: A circuit configuration with a deactivatable scan path, includes a number of function blocks each connected to at least one other of the function blocks. At least one sub-set of the connections is in the form of a respective interlocking element which can be switched through an activation line (Scan Enable) from a normal mode to a test mode and which has a further data input and data output. The further data inputs and outputs are connected to one another by data line sections in such a manner that the interlocking elements form a shift register which provides a scan path. At least one electrically programmable protection element, which either interrupts a given line or connects it to a defined potential, is disposed along the activation line (Scan Enable) and/or the data line sections.
    Type: Grant
    Filed: March 28, 2001
    Date of Patent: July 29, 2003
    Assignee: Infineon Technologies AG
    Inventors: Herbert Palm, Michael Smola, Stefan Wallstab
  • Publication number: 20030127709
    Abstract: An ohmic resistance is present between two parts of a conductor layer so that the size of the ohmic resistance can be ascertained and/or a semiconductor region is present in or on a layer forming the dielectric. The conductor layer is structured into a gate contact, a source contact, and a drain contact so that a transistor function or switching function is possible in the semiconductor region. Such a configuration allows an attempt to analyze the circuit integrated in the chip to be detected.
    Type: Application
    Filed: April 26, 2002
    Publication date: July 10, 2003
    Inventors: Bernhard Lippmann, Stefan Wallstab, Gunter Schmid, Rainer Leuschner
  • Publication number: 20030118190
    Abstract: A data processing method where data to be processed is feed to a processing unit. Supplying a current to the processing unit for operating the processing unit and supplying in a randomly controlled manner a part of the current fed to the processing unit, to an auxiliary circuit.
    Type: Application
    Filed: February 6, 2003
    Publication date: June 26, 2003
    Applicant: Siemens Aktiengesellschaft
    Inventors: Holger Sedlak, Peter Sohne, Michael Smola, Stefan Wallstab
  • Publication number: 20030065932
    Abstract: A circuit for monitoring an entry into a test mode of a chip circuit has a fusible link which can be fired via a firing transistor. A flipflop, which permits access to the test mode, is set by a resulting voltage drop, with the aid of an edge detector. The number of times the test mode has been accessed can be detected from the number of fired fusible links.
    Type: Application
    Filed: July 18, 2002
    Publication date: April 3, 2003
    Inventor: Stefan Wallstab
  • Publication number: 20030005315
    Abstract: An integrated security circuit, for example, a microcontroller for smart cards, includes a function unit executing a security function. A control device determines the number of executions of the security function per unit of time. The continued execution of the security function is blocked when a threshold value is exceeded. For such a purpose, an analog timekeeper incorporating a charge storage device is preferably provided that measures the elapsing time even with the supply potential disconnected. A usage counter is updated whenever the security function is called. The security circuit offers increased protection against statistical attacks. The complexity involved in the implementation is justifiably low. The security circuit is compatible with the existing system.
    Type: Application
    Filed: July 19, 2002
    Publication date: January 2, 2003
    Inventors: Helmut Horvat, Stefan Wallstab
  • Publication number: 20010025355
    Abstract: A circuit configuration with a deactivatable scan path, includes a number of function blocks each connected to at least one other of the function blocks. At least one sub-set of the connections is in the form of a respective interlocking element which can be switched through an activation line (Scan Enable) from a normal mode to a test mode and which has a further data input and data output. The further data inputs and outputs are connected to one another by data line sections in such a manner that the interlocking elements form a shift register which provides a scan path. At least one electrically programmable protection element, which either interrupts a given line or connects it to a defined potential, is disposed along the activation line (Scan Enable) and/or the data line sections.
    Type: Application
    Filed: March 28, 2001
    Publication date: September 27, 2001
    Inventors: Herbert Palm, Michael Smola, Stefan Wallstab