Apparatus for protecting secret information

• US 4,783,801 A
• Filed: 12/05/1984
• Issued: 11/08/1988
• Est. Priority Date: 12/29/1983
• Status: Expired due to Term

• Current Assignee: GAO Gesellschaft Fur Automation und Organisation mbH
• Original Assignee: GAO Gesellschaft Fur Automation und Organisation mbH
• Inventors: Kaule, Wittich
• Primary Examiner(s): Buczinski, Stephen C.
• Assistant Examiner(s): Gregory, Bernarr Earl
• Application Number:
  US06/678,284
• Time in Patent Office: 1,434 Days
• Field of Search: 128/22.08, 128/22.09, 235/487, 235/379, 235/380, 235/439, 307/200 A, 307/202.1, 340/522, 365/218, 380/2, 380/3, 380/4, 380/5, 380/59, 380/23, 380/25, 380/52
• US Class Current: 713/194
• CPC Class Codes: G06F 1/3215 Monitoring of peripheral devices
• CPC Class Codes: G06F 1/3275 Power saving in memory, e.g. RAM, cache
• CPC Class Codes: G06F 21/86 Secure or tamper-resistant housings
• CPC Class Codes: G06F 2221/2143 Clearing memory, e.g. to prevent the data from being stolen
• CPC Class Codes: G06Q 20/341 Active cards, i.e. cards including their own processing means, e.g. including an IC or chip
• CPC Class Codes: G07F 7/082 Features insuring the integrity of the data on or in the card
• CPC Class Codes: G07F 7/1008 Active credit-cards provided with means to personalise their use, e.g. with PIN-introduction/comparison system
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

In order to protect secret information in the electronic storage medium, the storage medium is provided in a housing protected against access. This housing contains one or more detector elements, via which erasure of the memory contents is initiated when unauthorized access is detected. The detector elements are connected with a clock unit which sets these elements into operation for short periods of time at certain time intervals. This clocked operation allows for the energy consumption of the overall arrangement to be reduced many times over without any essential restriction of security.

Claims

1. An apparatus for protecting information from unauthorized access, comprising a housing in which a storage medium containing the information is provided, detector means for detecting unauthorized access to the interior of the housing, means for initiating erasure of the secret information when the detector means reacts, a battery inside said housing for supplying energy at least to the detector means, clock means connected to said detector means which is arranged to enable operation of the detector means only over interrupted predetermined time intervals and wherein randomizer means are provided for varying the predetermined time intervals in accordance with randomized statistical distribution principles.

2. The apparatus as in claim 1, wherein said detector means comprises several detector elements, only one of which at a time is enabled at predetermined time intervals by the clock means, and including a switch means for enabling the normally non-enabled detector elements when irregular marginal conditions are present indicating an unauthorized attempt to gain access.

3. The apparatus as in claim 1, including means for analyzing the signals evoking response of the detector means.

4. The apparatus as in claim 1, wherein said detector means includes several detector elements and, including a switching element for combining the signals of several detector elements with each other, and means responsive to said signals for determining whether erasure of the memory is necessary.

5. The apparatus as in claim 4, wherein said means responsive to the signals is arranged to initiate erasure only according to the condition of a majority of detector elements.

6. The apparatus as in claim 4, wherein the switching element is arranged to assess the detector elements according to a different weighting and to determine the erasure decision based on such weighting.

7. The apparatus as in claim 1, wherein said secret information is maintained in said storage medium by the energy supplied by said battery.

8. An apparatus for protecting information from unauthorized access comprising a housing in which a storage medium containing the information is provided, detector means for detecting unauthorized access to the interior of the housing, means for initiating erasure of the secret information when the detector means reacts, and a battery inside said housing for supplying energy at least to the detector means, clock means connected to said detector means which is arranged to enable operation of the detector means only over interrupted predetermined time intervals, wherein said detector means comprises several detector elements, a distributor means, the latter including means for enabling said detector elements at said predetermined time intervals alternatingly, a randomizer means, and wherein said distributor means is arranged to cooperate with the randomizer means to enable selection of the detector element to be enabled.

9. The apparatus as in claim 8, including switch means arranged to enable further detector elements when the detector element in operation at the moment reacts to unauthorized access to the interior of the housing.

10. The apparatus as in claim 8, including means for analyzing the signals evoking response of the detector means.

11. The apparatus as in claim 8, wherein said detector means includes a switching element for combining the signals of several detector elements with each other, and means responsive to said signals for determining whether erasure of the memory is necessary.

12. The apparatus as in claim 11, wherein said means responsive to the signals is arranged to initiate erasure only according to the condition of a majority of detector elements.

13. The apparatus as in claim 11, wherein the switching element is arranged to assess the detector elements according to a different weighting and to determine the erasure decision based on such weighting.

14. The apparatus as in claim 8, wherein said information is maintained in said storage medium by the energy supplied by said battery.