METHOD AND SYSTEM FOR CALCULATING AND VERIFYING THE INTEGRITY OF DATA IN A DATA TRANSMISSION SYSTEM
First Claim
1. A method of calculating and verifying the integrity of data in a data communication system comprising a base station and one or more remote stations, the method including;
- transmitting one or more select instructions from the base station to said one or more remote stations, the select instruction or instructions containing a data field which matches a portion of an identity or other data field in one or more of the remote stations;
communicating from a selected remote station or stations a truncated reply containing identity data or other data of the remote station but omitting the portion transmitted by the base station; and
calculating in the base station a check sum or CRC from the data field originally sent and the truncated reply data received and comparing the calculated check sum or CRC with the check sum or CRC sent by the remote station.
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Accused Products
Abstract
A method is described of calculating and verifying the integrity of data in a data communication system. The system comprises a base station and one or more remote stations, such as in an RFID system. The method includes transmitting a select instruction from the base station to the one or more remote stations, the select instruction containing a data field which matches a portion of an identity or other data field in one or more of the remote stations; transmitting from a selected remote station or stations a truncated reply containing identity data or other data of the remote station but omitting the portion transmitted by the base station; calculating in the base station a check sum or CRC from the data field originally sent and the truncated reply data received and comparing the calculated check sum or CRC with the check sum or CRC sent by the remote station.
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Citations
41 Claims
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1. A method of calculating and verifying the integrity of data in a data communication system comprising a base station and one or more remote stations, the method including;
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transmitting one or more select instructions from the base station to said one or more remote stations, the select instruction or instructions containing a data field which matches a portion of an identity or other data field in one or more of the remote stations; communicating from a selected remote station or stations a truncated reply containing identity data or other data of the remote station but omitting the portion transmitted by the base station; and calculating in the base station a check sum or CRC from the data field originally sent and the truncated reply data received and comparing the calculated check sum or CRC with the check sum or CRC sent by the remote station. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 39)
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16. A system for calculating and verifying the integrity of data in a data communication system comprising a base station and one or more remote stations, the system comprising:
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transmitting means for transmitting select instructions from the base station to said one or more remote stations, the select instruction containing a data field which matches a portion of an identity or other data field in one or more of the remote stations;
transmitting means for transmitting from a selected remote station or stations a truncated reply containing identity data or other data of the remote station but omitting the portion transmitted by the base station; andcalculating means for calculating in the base station a check sum or CRC from the data field originally sent and the truncated reply data received and a comparator for comparing the calculated check sum or CRC with the check sum or CRC sent by the remote station. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 30, 34, 35)
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- 27. A transponder or tag for use in an REID system with a reader or interrogator, comprising a command decoder for decoding the command from the reader, a shift register for shifting data in the tag memory in synchronism with incoming mask data from the reader to a comparator, the comparator performing a bit by bit comparison between the mask data and the tag memory data, and a checksum or CRC generator.
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37. A method of calculating and verifying the integrity of data in a data communication system comprising a base station and one or more remote stations, the method including:
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transmitting a select instruction from the base station to said one or more remote stations, the select instruction containing a data field which matches a portion of an identity or other data field in one or more of the remote stations; communicating from a selected remote station or stations a truncated reply containing identity data or other data of the remote station but omitting the portion transmitted by the base station; and calculating in the base station a check sum or CRC from the data the truncated reply data received and comparing the calculated check sum or CRC with the check sum or CRC sent by the remote station. - View Dependent Claims (38)
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40. A method of calculating and verifying the integrity of data in a data communication system comprising one or more base stations and one or more remote stations, the method including:
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transmitting a select instruction from the remote station to said one or more remote base stations, the select instruction containing a data field which matches a portion of an identity or other data field in one or more of the remote base stations; transmitting from a selected bases station or stations a truncated reply containing identity data or other data of the base station but omitting the portion transmitted by the remote station; calculating in the remote station a check sum or CRC from the data the truncated reply data received; and comparing the calculated check sum or CRC with the check sum or CRC sent by the remote station.
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41. A reader or interrogator for use in a system with one or more remote stations, the reader including:
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a transmitter arranged to transmit one or more select instructions to said one or more remote stations, the select instruction or instructions containing a data field which matches a portion of an identity or other data field in one or more of the remote stations; a receiver arranged to receive a truncated reply containing identity data or other data of the remote station but omitting the portion transmitted by the reader or interrogator; calculating means for calculating a check sum or CRC from the field originally sent and the truncated reply data received, or calculated from the check sum or CRC from the truncated data alone; and a comparator for comparing the calculated check sum or CRC with the check sum or CRC sent by the remote station.
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Specification