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Data carrier and write/read device therefor

  • US 5,790,662 A
  • Filed: 10/30/1995
  • Issued: 08/04/1998
  • Est. Priority Date: 11/15/1994
  • Status: Expired due to Fees
First Claim
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1. A data carrier having an electronic circuit for storing and processing data and for communicating with a write/read device, said data carrier having unaltered and, by supplying thermal energy, irreversibly altered optical diffraction markings for proving authenticity of said data carrier, wherein said markings represent a digital signature which is machine readable and wherein data which is linked to said signature is stored in said electronic circuit.

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  • 4 Assignments
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