Server, method of group key notification and program

摘要

According to one embodiment, a server includes a message communicator, a key information storage, and a key controller. The message communicator is configured to communicate a message to a client. The key information storage is configured to store key information including at least a key value being value of key, a validity term of key, and assignment information of key. The key controller is configured to generate a key notification message including a key value of the client and a key update time when the message communicator receives a key request message from an authenticated client. The key value is corresponding with the assignment of the key information. The key update time decides from the validity term of the key and a validity term of authentication succeeded state of the client. The message communicator transmits the key notification message to the client.

主权项

1. A server comprising:
a message communicator configured to communicate a message to a client; a key information storage configured to store information about a key, the information including at least a key value, a first validity term, and assignment information; a key controller configured to generate a notification message about the key, the notification message including a value of a client key and an update time when the message communicator receives a key request message from an authenticated client, the key value corresponding with the assignment information, the update time deciding from the first validity term and a second validity term of authentication succeeded state of the client; wherein the message communicator transmits the notification message to the client; a client information storage configured to store client information having a need to authenticate the client; and an authenticator configured to authenticate the client from an authentication request message and the client information when the message communicator receives the authentication request message, wherein the key controller generates the notification message including the key value and the key update time when the message communicator receives the key request message from the authenticated client, the key value corresponding with the assignment information, the update time deciding from the first validity time and the second validity time, wherein the client information includes address information of the client, and wherein the key controller judges whether to include the update time in the notification message from the address information.