Abstract: The method enables authentication data to be communicated and checked between a transponder device (1) and a reader unit (2) of a vehicle in order to authorise access to the vehicle. The device includes a logic circuit (11), a non-volatile memory (13), an encryption and/or decryption circuit (12) and a first transmission and reception module (14, 16) of data signals (SD). The reader unit includes a microprocessor unit (21), a memory (22), a random number generator (24) and a second module (23, 25) for transmitting and receiving data signals (SD). A random number (RN1) generated in the reader unit is transmitted with a first encrypted function obtained using the random number and a secret key. The transponder device receives the random number and the first encrypted function. A new first encrypted function is calculated in the transponder device using a secret key identical to the secret key of the reader unit. This new first function is compared with the first received encrypted function.

Abstract: A data transfer interface system is provided that directly transfers data from one data storage drive to another data storage drive under the control of a host. The host and data storage drives are jointly connected to one another with data lines and control lines. Each data storage drive is connected separately to the host with a read/write command line. The host initializes the data storage drives providing initialization data to the drives where the data may include position information and commend information. After initialization, the host concurrently instructs one data storage drive to read the data from the drive while the other data storage drive writes the data to memory.