Data carrier and write/read device therefor
First Claim
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.
4 Assignments
0 Petitions
Accused Products
Abstract
A data carrier with an electronic circuit for storing and processing data is provided with an information strip with optically readable markings, and preferably a test field and an authentication feature. An optical interface, for example, can be provided for communication with a write/read device. The markings represent a digital signature. Testing of the authenticity of the data carrier can be done on the basis of the physical properties of the markings, the internal structure of the signature and/or the proof that a test number stored in the electronic circuit is equal to a number calculated from the signature according to a pre-determined function. The signature can also serve as a cryptographic key for encoding and decoding the data to be exchanged between the electronic circuit and the write/read device. The test field can be irreversibly modified when the data carrier is used. The write/read device contains an optical reading head for machine reading the markings and is optionally connected to a data processing point by means of a communication network.
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Citations
12 Claims
- 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.
Specification