Authentication of a host processor requesting service in a data processing network

Abstract

An object is authenticated by transmitting a random number to the object. The object has an integrated circuit chip including a memory and encryption circuitry. The memory stores information defining an encryption scheme preassigned to the object. The encryption circuitry reads the memory, and encrypts the random number according to the encryption scheme defined by the information read from the memory to produce encrypted data. The memory cannot be read from any output of the integrated chip, and the chip is constructed so that it is virtually impossible to recover the information contained in the memory by visual inspection, probing, or disassembly of the chip. The object is authenticated by checking whether the encrypted data is a correct result of encrypting the data using the encryption scheme pressigned to the object. The method can be used in a data processing system to authenticate each message transmitted by a host processor to a data processing device. For example, when a host logs into the data processing device, the data processing device transmits a series of random numbers to the host. The host encrypts the random numbers to produce a series of encrypted data, and the data processing device concurrently encrypts the random numbers to produce a series of encrypted values. The host inserts respective encrypted data into each message, and the data processing device authenticates each message by comparing the encrypted data in the message to a corresponding encrypted value.