| 摘要 |
<p>This invention is related to cloud server saving service and it is relates to technologies that allow you to decrypt and view encrypted data. In this invention, a cloud server provides cloud saving service for multiple user devices and it is composed of the communication unit that communicates between multiple user devices and the cloud server, the data storage unit that saves data received from at least one of multiple user devices, and the processing unit creates new data by encrypting saved data again. The saved data is encrypted data that is decrypted to original data by using decryption key 1, new data is encrypted data that is decrypted to original data by using decryption key 2. The processing unit refers to a re-encryption key different from decryption key 1 and 2 to re-encrypt data without decrypting to original data by using decryption key 1.</p> |
