Point of sale terminal having enhanced security

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;
• and
• a resiliently deformable conductive element, which defines a short circuit between at least some of said arrangement of electrical 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 at least one of said electrical contacts at least two corresponding locations on 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.