Point of sale terminal having enhanced security
A data entry device including a housing formed of at least two portions, data entry circuitry located within the housing, at least one case-open switch assembly operative to sense when the housing is opened and tamper indication circuitry operative to receive an input from the at least one case-open switch assembly and to provide an output indication of possible tampering with the data entry circuitry located within the housing. The at least one case-open switch assembly includes an arrangement of electrical contacts arranged on a base surface and a resiliently deformable conductive element, which defines a short circuit between at least some of the arrangement of electrical contacts only when the housing is closed.
1. A data entry device comprising:
a housing formed of at least two portions;
data entry circuitry located within said housing;
at least one case-open switch assembly operative to sense when said housing is opened; and
tamper indication circuitry operative to receive an input from said at least one case-open switch assembly and to provide an output indication of possible tampering with said data entry circuitry located within said housing,
said at least one case-open switch assembly including:
an arrangement of electrical contacts arranged on a base surface, said arrangement of electrical contacts including at least one of an outer ring contact and an inner intermediate ring contact, at least two outer intermediate ring contacts, arranged along an outer intermediate ring, and a central contact, said at least one of said outer ring contact and said inner intermediate ring contact being anti-tampering contacts and being coupled to said tamper indication circuitry; and
a resiliently deformable conductive element, which defines a short circuit between said central contact and said at least two outer intermediate ring contacts only when said housing is closed,
said resiliently deformable conductive element comprising:
an at least partially continuous circumferential flange fixed at least two locations thereat in electrical contact with said at least two outer intermediate ring contacts at least two corresponding locations at said base surface;
a circumferential portion having a cross sectional configuration which includes two mutually spaced arches;
a central portion disposed in a case-open operative orientation at a first distance from said base surface; and
a contact portion located interiorly of said central portion and disposed in a case-open operative orientation at a second distance from said base surface, less than said first distance, and in a non-case open operative orientation touching said central contact.
2. The entry device according to claim 1 and wherein said arches of said circumferential portion are at least at a distance from said base surface which exceeds said first distance.
3. The data entry device according to claim 1 and wherein said central portion is generally flat.
4. The data entry device according to claim 1 and wherein said contact portion is generally flat.
5. The data entry device according to claim 1 and wherein said resiliently deformable conductive element defines a short circuit between some, but not all, of said arrangement of electrical contacts when said housing is closed.
6. The data entry device according to claim 1 and wherein said contact portion of said resiliently deformable conductive element contacts said central contact when said housing is closed.
7. The data entry device according to claim 6 and wherein when said contact portion of said resiliently deformable conductive element contacts said central contact, said outer intermediate ring is thereby electrically connected with said central contact.
8. The data entry device according to claim 7 and wherein when said contact portion of said resiliently deformable conductive element contacts said central contact, no part of said resiliently deformable conductive element is in electrical contact with either said outer ring or said inner intermediate ring.
9. The data entry device according to claim 8 and wherein said input to said tamper indication circuitry includes an indication of whether said deformable conductive element is simultaneously in contact with both said central contact and said outer intermediate ring.
10. The data entry device according to claim 8 and wherein said input to said tamper indication circuitry includes an indication of whether said inner intermediate ring is short circuited with at least one of said central contact and said outer intermediate ring.
11. The data entry device according to claim 8 and wherein said input to said tamper indication circuitry includes an indication of whether said outer ring is short circuited with said outer intermediate ring.
12. The data entry device according to claim 1 and wherein a separation between said contact portion of said resiliently deformable conductive element and said central contact is less than 0.1 mm.
13. The data entry device according to claim 1 and wherein a force required to establish electrical contact between said contact portion of said resiliently deformable conductive element and said central contact is approximately 200 grams.
14. A case-open switch assembly for a data entry device including a housing, data entry circuitry, located within said housing, and tamper indication circuitry, the case-open switch assembly comprising:
an arrangement of electrical contacts arranged on a base surface, said arrangement of electrical contacts including at least one of an outer ring contact and an inner intermediate ring contact, at least two outer intermediate ring contacts, arranged along an outer intermediate ring, and a central contact, said at least one of said outer ring contact and said inner intermediate ring contact being anti-tampering contacts and being coupled to said tamper indication circuitry; and
a resiliently deformable conductive element, which defines a short circuit between said central contact and said at least two outer intermediate ring contacts only when said housing is closed,
said resiliently deformable conductive element comprising:
an at least partially continuous circumferential flange fixed at least two locations thereat in electrical contact with said at least two outer intermediate ring contacts at least two corresponding locations at said base surface;
a circumferential portion having a cross sectional configuration which includes two mutually spaced arches;
a central portion disposed in a case-open operative orientation at a first distance from said base surface; and
a contact portion located interiorly of said central portion and disposed in a case-open operative orientation at a second distance from said base surface, less than said first distance, and in a non-case open operative orientation touching said central contact,
said case-open switch being operative to provide an output indication to said tamper indication circuitry of possible tampering with said data entry circuitry located within said housing.