Patent ID: 9088557
Filing Date: 2015-07-21
Classification: H04L

Abstract:
1. A non-transitory computer readable medium storing an encryption key management program that causes a computer to perform a process for managing an encryption key, the encryption key management program, when executed by the computer, causes the computer to execute: a group shared key encryption step of encrypting, using authentication information used for authenticating each of a plurality of users, a group shared key, that is an encryption key shared and used by the plurality of users in one group, of a plurality of groups, that the plurality of users belong, to create an encrypted group shared key, and storing the encrypted group shared key in a storage device; and an encryption key sending step of performing, upon receiving a request to send an encryption key, a user authentication with respect to a client terminal that issued the request, and sending as a response to the request the encrypted group shared key corresponding to a user of the user authentication if the user authentication is approved, wherein in the group shared key encryption step, the encryption key management program causes the computer to create the encrypted group shared key so that the group shared key obtained by decrypting the encrypted group shared key becomes an encryption key that is different for each of the plurality of groups, wherein the encryption key management program further causes the computer to execute a private key encryption step of encrypting, using user authentication information for authenticating each user, a private key, that is an encryption key unique to each user and is used by each user individually, to create an encrypted private key, and storing the encrypted private key in a storage device, and wherein in the encryption key sending step, if the user authentication is approved, the encryption key management program causes the computer to send the encrypted private key corresponding to a user of the user authentication along with the encrypted group shared key as a response to the request.