Data generation apparatus, data recording system, and program product

A data recording system comprising:

• a data generation apparatus including
• a processor;
• and
• a memory containing instructions that cause the processor to execute a data generation process that includes
• obtaining target data sequentially from time-series data, the target data including n (n being an integer greater than or equal to 2) data items in a predetermined section of the time-series data, calculating parameter information that satisfies a (k−1) order polynomial based on the target data, the (k−1) order polynomial including k random values, k being an integer greater than or equal to and less than n,
• associating the target data to the parameter information, outputting the target data and the parameter information associated to the target data,
• attaching a first signature to secret information based on a secret distributed protocol, the secret information being calculable by using k pairs of data including the target data and the parameter information associated to the target data, and
• outputting the secret information attached with the first signature;
• and a data recording apparatus connected to the data generation apparatus, wherein the processor of the data generation apparatus is further configured to transmit the target data, the parameter information associated to the target data, and the secret information attached with the first signature,
• wherein the data recording apparatus includes the processor, and the memory containing instructions that cause the processor to execute a process that includes receiving a first pair of data including the target data and the parameter information associated to the target data,
• and determining whether a signature verification process is a success depending on whether a number of the received first pair is greater than or equal to k,
• wherein the processor of the data generation apparatus is further configured to attach a second signature to a hash value of the target data and output the hash value of the target data attached with the second signature, and
• wherein the processor of the data generation apparatus is further configured to transmit a second pair of data including the hash value of the target data and the hash value of the target data attached with the second signature.

A non-transitory computer readable medium storing a program for causing a processor to execute a data generation process, the data generation process comprising:

• obtaining target data sequentially from time-series data, the target data including n (n being an integer greater than or equal to 2) data items in a predetermined section of the time-series data,
• calculating parameter information that satisfies a (k−1) order polynomial based on the target data, the (k−1) order polynomial including k random values, k being an integer greater than or equal to 1 and less than n,
• associating the target data to the parameter information,
• outputting the target data and the parameter information associated to the target data,
• attaching a first signature to secret information based on a secret distributed protocol, the secret information being calculable by using k pairs of data including the target data and the parameter information associated to the target data, and
• outputting the secret information attached with the first signature,
• wherein the data generation process further comprises:
• transmitting the target data, the parameter information associated to the target data, and the secret information attached with the first signature,
• attaching a second signature to a hash value of the target data and output the hash value of the target data attached with the second signature, and
• transmitting the hash value of the target data and the hash value of the target data attached with the second signature.