The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 01, 1991
Filed:
Oct. 04, 1990
Robert C Gilberg, San Diego, CA (US);
Chinh Hoang, San Diego, CA (US);
James E Smith, Escondido, CA (US);
General Instrument Corporation, New York, NY (US);
Abstract
An integrated circuit chip includes a secure memory element that stores secret data, an opaque layer of material encapsulating the chip, and means for eliminating the secret data from the secure memory element in the event that the encapsulation material is removed from the chip. The eliminating means comprise a protective circuit encapsulated by the encapsulation material and coupled to the secure memory element. The protective circuit incldues a light sensitive element having a current characteristic that has a detectable change upon exposure to light; means for detecting said current change when the light sensitive element is exposed to light; and switching means coupled to the secure memory element and the detecting means for causing the secret data to be removed from the secure memory element in response to said current change produced by the light sensitive element when the light sensitive element is exposed to light, such that should the encapsulation material be removed from the chip, the secret data is eliminated from the memory element.