Patent · US Expired

Tamper-resistant packaging for protection of information stored in electronic circuitry

US4860351A · kind A · utility

121Cited by
30References
13Claims
0Family size

Assignee

Inventor

Key dates

Filing dateNov 5, 1986
Grant dateAug 22, 1989
Priority date
Expiry dateNov 5, 2006

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH01L2924/0002
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A tamper-resistant package for protection of information stored in electronic circuitry 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 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.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.