Browse Prior Art Database

A Tamper Protection Switch

IP.com Disclosure Number: IPCOM000015027D
Original Publication Date: 2001-Oct-18
Included in the Prior Art Database: 2003-Jun-20
Document File: 2 page(s) / 73K

Publishing Venue

IBM

Abstract

To protect information stored in a volatile memory device from tampering or tapping, one of the most general schemes is to use a micro switch (or limit switch) such as shown in Figure 3 and 4 below. However weakness of this method is that the shape, the function and the mechanism of micro switch are well known in public. When its existence and location are identified from outside of the equipment by means of X-rays for example, it is easy to break the protection scheme: by opening a small hole in the case lid, pushing down the micro switch to normal position during complete removal of the case lid. The disclosed invention is illustrated in Fig. 1 and 2. The invented apparatus functions as a transfer switch, and consiss of (1) Normally opened contacts, (2) Nomally closed contacts, (3) Molded enclosure for the contacts, (4)insulator with conductive ring to shorten (1), and (5) Insulator to open (2). As an optional enhancement feaure, x-ray reflecting or absorbing scheme is employed for the molded enclosure (3).

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A Tamper Protection Switch

    To protect information stored in a volatile memory device from tampering or tapping, one of the most general schemes is to use a micro switch (or limit switch) such as shown in Figure 3 and 4 below. However weakness of this method is that the shape, the function and the mechanism of micro switch are well known in public. When its existence and location are identified from outside of the equipment by means of X-rays for example, it is easy to break the protection scheme: by opening a small hole in the case lid, pushing down the micro switch to normal position during complete removal of the case lid.

The disclosed invention is illustrated in Fig. 1 and 2. The invented apparatus functions as a transfer switch, and consiss of (1) Normally opened contacts, (2) Nomally closed contacts, (3) Molded enclosure for the contacts, (4)insulator with conductive ring to shorten (1),
and (5) Insulator to open (2).

As an optional enhancement feaure, x-ray reflecting or absorbing scheme is employed for the molded enclosure (3).

A T am per P rotection S w itch of this invention

In s u la to r C onnected to Upper C ase Lid

VD D

U pper C ase L id

(4)Insulator w /

(5)Insulator

C onductive

R in g

"A "

"A "

SR A M

Vdd

"B "

B ackup Battery

(2 )N o rm a lly C lo s e d Contacts

(1 )N o rm a lly O p e n Contacts

"B "

B ackup B a tte ry

SR A M

Cap.

'A ' shorted, 'B ' opened, w hen the case lid proppery sheeted.

(3)M olded enclosure

Low er C ase Lid

C ro ss S e c tio...