Increased-security identification card system

A tamper-evidencing, self-validating identification card for use in a security-document system having a polarizing viewer for use as a validation viewer, comprising:

• a data substrate having a display surface upon which visible indicia may be displayed;
• a polarization-altering transparent overlay lamination permanently attached to said data substrate, whereby any visible indicia on said display surface remains visible through said polarization-altering overlay lamination;
• and
• polarization-coded personalizing indicia borne by said polarization-altering overlay lamination as physical changes viewable through said polarizing viewer.

A security document system having a polarization-altering identification document and a polarizing tamper-detection viewer, which viewer when superposed over said identification document in viewing attitude provides for such identification document both a view of otherwise non-visible data and visible evidence of any tampering with such identification document,

• characterized by:
• a data substrate having personalization indicia forming a base print of low-security indicia readable on said identification document without the need for a viewer;
• and
• a personalized polarization-altering overlay, permanently attached to said data substrate base print in such fashion that the low-security indicia carried on the surface of the base print is directly viewable through said overlay;
• said overlay being encoded with normally unreadable semi-secure indicia made readable under the influence of the polarizing tamper-detection viewer, the polarization direction of the viewer being so oriented that the composite of the polarizing viewing device and said personalized polarization-altering overlay superposed in viewing attitude makes the encoded indicia in said overlay visually readable.