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Correlation System for Security Validation and Verification Using An Encoded Phase Mask

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Final rept. 17 Dec 1997-31 Dec 2000

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Verification technologies are needed to confirm the identity of personnel and to validate the authenticity of manufactured products. Rapid advances in computers, printers scanners, and copiers have made it increasingly easy to reproduce security emblems traditionally used for verification and authentication. Even holograms, once considered impenetrable, are now routinely counterfeited using techniques such as holographic contact copying. To circumvent the effectiveness of intensity sensitive devices to copy traditional security emblems, the use of complex phase patterns has been proposed. An ID card is produced by bonding a phase mask to some primary identification pattern such as a fingerprint. A nonlinear joint transform correlator is then used to match the ID card to an identical phase mask that is part of an automated reader. However, such a phase encoded ID card could be copied by using innovative holographic techniques. To avoid this, MetroLaser has developed an innovative holographic technique that utilizes an ID card that is an inseparable combination of an information wavefront and another complex wavefront, both unknown to the potential counterfeiter. The two patterns on the card are deconvolved using a Key Hologram that is part of the reader, resulting in a nearly ideal security system.

Subject Categories:

  • Electrooptical and Optoelectronic Devices
  • Holography

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