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    3.
    发明专利
    未知

    公开(公告)号：DE69031645D1

    公开(公告)日：1997-12-04

    申请号：DE69031645

    申请日：1990-07-28

    Applicant: IBM

    Inventor： DOUBLE GLEN PAUL ,  WEINGART STEVE HARRIS

    IPC: G06F12/14 ,  G06F21/00 ,  G06F21/06 ,  H04L9/10 ,  G06F1/00

    Abstract: The present invention provides an intrusion barrier for protecting against mechanical or chemical intrusion into an electronic assembly, especially one containing volatile memory. It includes a screen material surrounding the electronic assembly which screen material has formed thereon fine conductive lines in close proximity to each other. The lines are formed of conductive particles of material dispersed in a solidified matrix of a material which looses its mechanical integrity when removed from the screen. An electrical supply and signal detection circuit is provided which generates an output signal responsive to a given change in resistance of the conductive lines, such that if the resistance changes are a result of a mechanical or chemical attack, a signal is generated which can cause the erasure of the volatile memory. Also, preferably radiation detection and temperature sensing circuits are provided to cause erasure of the volatile memory responsive to detection of a given intensity of radiation or a temperature below a given value.

    7.
    发明专利
    未知

    公开(公告)号：DE3782328T2

    公开(公告)日：1993-04-22

    申请号：DE3782328

    申请日：1987-12-18

    Applicant: IBM

    Inventor： ABRAHAM DENNIS GEORGE ,  DOUBLE GLEN PAUL ,  NECKYFAROW STEVEN WILLIAM ,  ROHLAND WILLIAM STANLEY ,  TUNG MIN-HSIUNG GEORGE

    IPC: G06K19/07 ,  B42D15/10 ,  G06F9/445 ,  G06K17/00 ,  G07F7/10

    Abstract: A smart card (10) which has a instruction processor (12) which is connected to a changeable memory (16) in which application programs are stored. The card is manufactured partially blank, or without an application program stored thereon, and an application program is then loaded into the changeable memory, i.e., by downloading it from a mainframe computer. In this manner, the application program in a smart card may be changes by an authorized party. Further, a flag (22) indicates whether a program has been loaded on a smart card. Also disclosed is a method of securing the program from tampering by unauthorized parties where, in response to certain instructions (such as a dump of the application program), key portions are erased prior to execution. Application programs are loaded onto the card through the use of a double timed reset, the first of which writes a predetermined sequence on the card for a set time interval. The second reset before the end of the set time interval then indicates that a program load function is to occur and causes key selected portions of the memory to be overwritten and erased to protect key data from the previous program from being maintained or used later.

    8.
    发明专利
    未知

    公开(公告)号：DE3782328D1

    公开(公告)日：1992-11-26

    申请号：DE3782328

    申请日：1987-12-18

    Applicant: IBM

    Inventor： ABRAHAM DENNIS GEORGE ,  DOUBLE GLEN PAUL ,  NECKYFAROW STEVEN WILLIAM ,  ROHLAND WILLIAM STANLEY ,  TUNG MIN-HSIUNG GEORGE

    IPC: G06K19/07 ,  B42D15/10 ,  G06F9/445 ,  G06K17/00 ,  G07F7/10

    Abstract: A smart card (10) which has a instruction processor (12) which is connected to a changeable memory (16) in which application programs are stored. The card is manufactured partially blank, or without an application program stored thereon, and an application program is then loaded into the changeable memory, i.e., by downloading it from a mainframe computer. In this manner, the application program in a smart card may be changes by an authorized party. Further, a flag (22) indicates whether a program has been loaded on a smart card. Also disclosed is a method of securing the program from tampering by unauthorized parties where, in response to certain instructions (such as a dump of the application program), key portions are erased prior to execution. Application programs are loaded onto the card through the use of a double timed reset, the first of which writes a predetermined sequence on the card for a set time interval. The second reset before the end of the set time interval then indicates that a program load function is to occur and causes key selected portions of the memory to be overwritten and erased to protect key data from the previous program from being maintained or used later.

    MAGNETIC READ HEAD
    9.
    发明专利
    MAGNETIC READ HEAD 未知

    公开(公告)号：DE3370392D1

    公开(公告)日：1987-04-23

    申请号：DE3370392

    申请日：1983-12-15

    Applicant: IBM

    Inventor： BEAM DAVID LARRY ,  DOUBLE GLEN PAUL

    IPC: G11B5/39

    Abstract: A read head is formed from a magneto resistive element (14) extending coplanar with a magnetically permeable yoke member (15). The yoke member includes leg portions (16, 17, 18) forming pole faces. A first pole face extends adjacent to one edge of the element. A second pole face extends adjacent to the element. In operation the read head is located so that the element extends perpendicular to a surface (11) formed with flux transitions to be detected. The first pole face is located on the edge of the element remote from the surface. The second pole face extends over at least one flux transition (19) adjacent to a flux transition (21) beneath the element.

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