Patent ID: 7558963

Claim:
A communication device for verifying whether application data is valid in order to determine whether to execute the application data on the communication device, the verification of the application data using a first file, a second file, and a third file, the first file comprising the application data, the second file comprising application validity data used to verify validity of the application data in the first file and containing data indicating a location where a program, which is contained in the first file and run in the communication device, is stored, the first file, second file, and the third file being separate from one another, the third file comprising second file validity data calculated with a one-way function and used to verify the second file, the communication device comprising: a receiver for receiving the first file, second file, and third file; at least one processor for: generating a second file calculated value using the one-way function, at least a part of the second file being input to the one-way function to generate the second file calculated value; comparing the second file calculated value with the second file validity data in the third file; and determining whether the second file is valid based on the comparing of the second file calculated value with the second file validity data in the third file; and executing the application data on the communication device if the application data is verified using the application validity data in the second file and if it is determined that the second file is valid.