| 摘要 |
A user terminal calculates a trail from data to be verified using a secret key prestored as a natural number (p), and when transmitting a request to prove data retention, generates random numbers as a seed, and transmits the generated random numbers to a provision server, the provision server calculates first evidence data from the received random numbers and the stored data to be verified, and transmits the calculated first evidence data to the user terminal, and the user terminal calculates second evidence data from the random numbers as the seed and the trail using a pseudorandom number generator, and on the basis of a result of a comparison between a residue resulting from a public parameter (N) of the received first evidence data and the second evidence data, determines whether the provision server has stored the data to be verified. |
