| 摘要 |
An object of the present invention is to propose a data possession verification system and method which can verify with a small communication amount or a small calculation amount whether a server device possesses verification target data deposited to the server device by a user terminal. In the data possession verification system and method for verifying whether a server device possesses the verification target data deposited to the server device by the user terminal, the user terminal transmits predetermined verification information to the server device, and the server device calculates server side evidence data, which is specific to the verification target data and has a smaller data size than that of the verification target data, by using the possessed verification target data and the verification information, and transmits the calculated server side evidence data to the user terminal. The user terminal compares user terminal side evidence data based on the verification information and the server side evidence data transmitted from the server device, and determines based on a result of the comparison that the server device possesses the verification target data. |
