Patent ID: 7610488

Claim:
A data processing device comprising: an authenticating means for authentication with a device to be authenticated on the basis of key data; and a key generating means for generating said key data on the basis of the data received from said authenticating means and providing the same to said authenticating means, wherein said authenticating means provides device identification data identifying the device to be authenticated, master key data, original key data, and service identification data to said key generating means, said service identification data including first service identification data corresponding to a first service to be received by a user of the device to be authenticated and second service identification data corresponding to a second service to be received by the user of the device to be authenticated, said key generating means selects one of said first service identification data or said second service identification data, said key generating means selects a key generation algorithm corresponding to selected service identification data from among a plurality of different key generation algorithms, and said key generating means generates said key data by inputting the device identification data, the master key data, the original key data, and the selected service identification data into said selected key generation algorithm.