A tamper sensor assembly includes a lid having a surface and a sensor substrate on the surface of the lid. The sensor substrate has conductive lines that extend across at least a major portion of the surface of the lid and conform to three dimensional characteristics of the surface of the lid. The security processor is electrically connected to the conductive lines of the sensor substrate and is configured to identify occurrence of tampering with the lid based on an electrical characteristic of signals conducted through the conductive lines, and to perform an anti-tampering operation responsive to identifying occurrence of tampering.