US 2004/0003261 A1 · Information processing method and information processing apparatus

Abstract

A code stream and data indicating a normalization method are inputted to a normalization processing unit 21, and the normalization processing unit applies normalization processing to the code stream to generate a normalized code stream. Next, when signature data is inputted, a verification processing unit 22 performs encryption and decryption processing with respect to the signature data using a public key Kp and calculates a Hash value (first Hash value) and, on the other hand, calculates a Hash value of the normalized code stream (second Hash value). Next, the verification processing unit compares the first Hash value and the second Hash value and, if the first Hash value and the second Hash value are equal, judges that the code stream is not falsified. On the other hand, if the first Hash value and the second Hash value are not equal, the verification processing unit judges that the code stream is falsified.

Claims14

Dependent claims

An information processing method performed by a verification device which verifies whether or not falsification has been applied to compression-coded data to be outputted from a coding device, comprising:

a holding step of holding verification data which is obtained based upon compression-coded data in a normalized state generated in said coding device;
an input step of inputting compression-coded data, which is obtained by coding coding object data in said coding device, and normalization information, which indicates a reference for converting the compression-coded data into the normalized state, from said coding device;
a normalization step of normalizing the compression-coded data, which is inputted in said input step, using the normalization information;
a first calculation step of calculating a first value based upon the verification data;
a second calculation step of calculating a second value based upon the compression-coded data normalized in said normalization step;
and
a determination step of determining whether or not falsification has been applied to the compression-coded data, which is inputted in said input step, according to a result of comparison of the first value and the second value.

4 more elements

Dependencies are inferred from the claim text.

Information processing method and information processing apparatus

Life of this patent

Information processing method and information processing apparatus

Life of this patent

Abstract

Claims14