Patent ID: 8050447

Claim:
An information processing method comprising: a discrimination information acquisition step of acquiring digital data discrimination information for discriminating digital data from a plurality of digital data; a specifying information acquisition step of acquiring specifying information for specifying partial data included in the discriminated digital data; a partial data acquisition step of acquiring, from the discriminated digital data, the partial data corresponding to the specifying information for specifying partial data; a combined data generation step of generating combined data including the digital data discrimination information, the specifying information for specifying partial data, and the partial data; a cryptographic key information acquisition step of acquiring cryptographic key information for generating verification data; a verification data generation step of generating verification data, to verify whether or not the specified partial data is altered, from the combined data generated in said combined data generation step, based on the cryptographic key information acquired in said cryptographic key information acquisition step, wherein the verification data is either a MAC (message authentication) or a digital signature; and an output step of outputting the partial data and the verification data.