| 摘要 |
PROBLEM TO BE SOLVED: To allow for continuous decryption of protection data with an old decryption key before changing a password, without performing re-authentication, when the password is changed in parallel, while an authenticated user is using a system.SOLUTION: In an encryption key management system, a server acquires a master key by decrypting an encrypted key, acquired from the key information with a combination of the user ID included in the authentication information and the revision as a search key, by a key hash included in the authentication information, when changing the password inputted in the user authentication into a new password, and creates a new encrypted key based on the new password and the master key, and stores the new key information associating the user ID, the new revision related to the new password and the new encrypted key, in the key information storage means, while coexisting with other key information related to the same user ID.SELECTED DRAWING: Figure 1 |
