2.
    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

    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.

    4.
    发明专利
    未知

    公开(公告)号:DE3789002T2

    公开(公告)日:1994-08-04

    申请号:DE3789002

    申请日:1987-11-03

    Applicant: IBM

    Abstract: A tamper-resistant package for protection of information stored in electronic circuitry (10) includes apparatus for distributing electro-magnetic energy within a region occupied by the circuit to be protected. A sensing arrangement senses the distribution of the energy. In a preferred embodiment, electrical current is distributed through a coil (30) or coils within which the circuit to be protected resides. The sensor includes an integrating circuit, and the output of the integrating circuit is presented to both a sample and hold circuit and to a comparator. The comparator has high and low reference input terminals which are fed from a voltage divider to which is also applied an output from the sample and hold circuit. The high and low reference inputs to the comparator are, by reason of the sample and hold circuit, adaptive. The comparator produces an output if its input is outside the limits established by the high and low reference inputs; that output of the comparator is taken as evidence of tampering. An impairing device responds to the comparator output to obliterate, destroy or otherwise impair the information stored in the electronic circuit which is being protected.

    5.
    发明专利
    未知

    公开(公告)号:DE3789002D1

    公开(公告)日:1994-03-17

    申请号:DE3789002

    申请日:1987-11-03

    Applicant: IBM

    Abstract: A tamper-resistant package for protection of information stored in electronic circuitry (10) includes apparatus for distributing electro-magnetic energy within a region occupied by the circuit to be protected. A sensing arrangement senses the distribution of the energy. In a preferred embodiment, electrical current is distributed through a coil (30) or coils within which the circuit to be protected resides. The sensor includes an integrating circuit, and the output of the integrating circuit is presented to both a sample and hold circuit and to a comparator. The comparator has high and low reference input terminals which are fed from a voltage divider to which is also applied an output from the sample and hold circuit. The high and low reference inputs to the comparator are, by reason of the sample and hold circuit, adaptive. The comparator produces an output if its input is outside the limits established by the high and low reference inputs; that output of the comparator is taken as evidence of tampering. An impairing device responds to the comparator output to obliterate, destroy or otherwise impair the information stored in the electronic circuit which is being protected.

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