Data transmission method, and tachograph system
First Claim
1. A data transmission method for a tachograph system for transmission of digital messages between a velocity transmitter and a recording unit each having a respective key pair with a public key and a private key and a certificate derived from the respective key pair, the method comprising:
- transmitting the velocity transmitter public key and the velocity transmitter certificate from the velocity transmitter to the recording unit;
transmitting the recording unit public key and the recording unit certificate from the recording unit to the velocity transmitter;
checking the velocity transmitter public key and the velocity transmitter certificate by the recording unit;
checking the recording unit public key and the recording unit certificate by the velocity transmitter;
capturing sensor data by the velocity transmitter;
producing a digital message by the velocity transmitter from the sensor data;
producing authentication information item for the digital message by the velocity transmitter based on its key pair;
transmitting the message and the authentication information item from the velocity transmitter to the recording unit; and
processing the message in the recording unit based a validity of the authentication information item as checked by the recording unit.
1 Assignment
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Accused Products
Abstract
In a data transmission method for a tachograph system, digital messages are transmitted between a speed transmitter (MS) and a recording unit (RU). The digital messages contain a pair of keys including a public key (KMP, KRP) and a private key (KMS, KRS), as well as a certificate (ZM, ZR) derived from the respective pair of keys. The public keys (KMP, KRP) and the certificates (ZM, ZR) are mutually verified between the recording unit (RU) and the speed transmitter (MS). If the verification is positive, the speed transmitter (MS) detects sensor data, and a digital message is generated therefrom. In addition, the speed transmitter (MS) generates authentication data for the message in accordance with the pair of keys (KMP, KMS) thereof. The message and the authentication data are transmitted to the recording unit and are processed there in accordance with a validity of the authentication data verified by the recording unit (RU).
28 Citations
15 Claims
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1. A data transmission method for a tachograph system for transmission of digital messages between a velocity transmitter and a recording unit each having a respective key pair with a public key and a private key and a certificate derived from the respective key pair, the method comprising:
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transmitting the velocity transmitter public key and the velocity transmitter certificate from the velocity transmitter to the recording unit; transmitting the recording unit public key and the recording unit certificate from the recording unit to the velocity transmitter; checking the velocity transmitter public key and the velocity transmitter certificate by the recording unit; checking the recording unit public key and the recording unit certificate by the velocity transmitter; capturing sensor data by the velocity transmitter; producing a digital message by the velocity transmitter from the sensor data; producing authentication information item for the digital message by the velocity transmitter based on its key pair; transmitting the message and the authentication information item from the velocity transmitter to the recording unit; and processing the message in the recording unit based a validity of the authentication information item as checked by the recording unit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A tachograph system comprising a velocity transmitter and a recording unit each having a respective key pair comprising a public key and a private key and a certificate derived from the respective key pair to reciprocally authenticate themselves by their public keys and their certificates, wherein
the velocity transmitter configured to: -
check the public key and the certificate of the recording unit; capture sensor data; produce a digital message from the sensor data and an authentication information item for the message on the basis of the key pair of said velocity transmitter, and transmit the message with the authentication information item to the recording unit; and the recording unit configured to; check the public key and the certificate of the velocity transmitter; check the authentication information item; and process the message on the basis of a validity of the authentication information item. - View Dependent Claims (15)
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Specification