Security device for sensitive data

• US 4,807,284 A
• Filed: 06/05/1987
• Issued: 02/21/1989
• Est. Priority Date: 09/24/1986
• Status: Expired due to Fees

• Current Assignee: NCR Corporation
• Original Assignee: NCR Corporation
• Inventors: Kleijne, Theodoor A.
• Primary Examiner(s): CANGIALOSI, SALVATORE A
• Application Number:
  US07/058,730
• Time in Patent Office: 627 Days
• Field of Search: 380/314, 380/52, 380/59, 340/825.54
• US Class Current: 713/194
• 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: H05K 1/0275 Security details, e.g. tampering prevention or detection
• CPC Class Codes: H05K 1/14 Structural association of two or more printed circuits providing electric connection to or between printed circuits H05K1/11, H01R12/00

Abstract

A device (10) for protecting stored sensitive data includes a housing (12) formed by six plates P1-P6 inclusive each carrying a conductive path segment formed by thick film deposition techniques and each having a winding configuration covering substantially the entire inner surface of the plate. The four side plates P2-P5 inclusive are mounted on a printed circuit board (PCB 14) which is mounted on the base plate (P6). The conductive path segments on the side and base plates (P2-P6 inclusive) are interconnected to form a wire mesh by conductive epoxy material connecting the path segments on the side and base plates (P2-P6 inclusive) with conductive tracks on the PCB (14). The conductive path segment on the top plate (P1) is connected by conductive wires (58, 60), which extend through plated through holes (B9, B10) in the PCB (14).

Claims

1. A security device for protecting stored sensitive data comprising:

a closed housing containing memory means adapted to store sensitive data and including atop plate, a base plate and a plurality of side plates having conducted path segments formed in meandering configurations over substantially the entire inner surface areas of the respective parts;

interconnection means arranged to electrically interconnect said conductive path segments to form conductive path means, the interruption of which, brought about by an attempt to penetrate said housing, causes the erasure of the contents of said memory means; and

a printed circuit board on which said memory means is supported, wherein said side plates are mounted on the top surface of said printed circuit board which is mounted on said base plate, and wherein said interconnection means includes conductive track means provided on said printed circuit board and conductive wires extending from said top plate through electrically conductive apertures in said printed circuit board to thereby directly connect with a part of said conductive track means on said printed circuited board.

2. The security device as claimed in claim 1, wherein said conductive path segments are formed by a conductive thick film having thickness in the range of from 10 microns to about 15 microns.

3. The security device as claimed in claim 2, wherein said interconnection means includes electrically conductive epoxy material connecting conductive islands on said printed circuit board with conductive islands on said side plates.

4. The security device as claimed in claim 3, wherein said interconnection means includes electrically conductive epoxy material connecting conductive islands on said base plate with conductive regions extending through said printed circuit board.

5. The security device as claimed in claim 4, wherein said conductive path means is connected between voltage supply means and a reference potential means, and said device further includes a sensing circuit adapted to detect the interruption of the current path between said voltage supply means and said reference potential means.

6. The security device as claimed in claim 5, wherein said sensing circuit includes capacitive means connected to said conductive path means, and an inverter, responsive to the state of said capacitive means to produce a reset signal for resetting said memory means in response to interruption of said conductive path means.