Verification data generating apparatus, data verification apparatus and storage medium for storing verification data generating program

A data verification apparatus comprising:

• a verification value holding element that holds a verification value;
• a reference verification value generating element that receives verification data that is a plurality of data bodies and a signature value attached thereto and generates a reference verification value based on the verification value and the plurality of data bodies;
• an authenticating element that collates a verification value obtained from the signature value with the reference verification value and authenticates the verification data if the signature value and the reference verification value are consistent with each other;
• and
• a verification value updating element that updates the verification value with the reference verification value if the verification value obtained from the signature value and the reference verification value are consistent with each other.

A storage medium readable by a computer, the storage medium storing a program of instructions executable by the computer to perform a function for generating verification data, the function comprising the steps of:

• holding a verification value;
• generating a plurality of data bodies;
• generating a new verification value based on both the verification value and the data body whenever the data body is generated and updating the verification value with the new verification value;
• storing the plurality of data bodies in order of being generated;
• and
• generating a signature value by using the verification value on receiving a verification data outputting request and outputting verification data including the plurality of data bodies and the signature value.