Abstract: A method and system for updating and using a digital certificate, and the method comprises: a first terminal establishing a secure link with an access point and using the secure link to send a certificate updating request to the access point, where the certificate updating request includes a digital certificate to be updated which is currently used by the first terminal; and the access point sending the digital certificate to be updated to a local Authentication Service Unit which issues the certificate to be updated; and the local Authentication Service Unit which issues the digital certificate to be updated verifying the digital certificate to be updated, and after the digital certificate is verified to be valid, a local Authentication Service Unit corresponding to the access point generating a new digital certificate of the first terminal and sending the new digital certificate to the first terminal through the access point.

Abstract: A security service control method and a WLAN terminal are provided, and the method includes: stopping a WPI service between a WLAN terminal and an AP when the WLAN terminal creates a security service of an IP layer and/or a layer above the IP layer, wherein the WPI service comprises: encrypting a data link layer message to be transmitted, and decrypting a received data link layer message. After the WPI service is stopped, when the WLAN terminal cancels the security service of the IP layer and/or the layer above the IP layer, the WLAN terminal completes processes of removing association, association, user authentication and key negotiation in turn with the WLAN AP, and uses a session key obtained through the key negotiation to recover the WPI service. The calculating resources can be saved by using the present invention.

Abstract: An IMS multimedia communication method and system, terminal and IMS core network, wherein the IMS multimedia communication method includes signal negotiation performed between the terminal and the IMS core network, and during the process of signal negotiation, an IPSec-ESP security association for media transmission is established between the terminal and the IMS core network; the media content is transmitted between the terminal and the IMS core network via the IPSec-ESP security association for media transmission. The security of media content transmitted between the terminal and the IMS core network is maintained solving the safety problem of multimedia communication under IMS in related technology, and preventing the media content from being maliciously stolen and tampered by others when transmitted between the terminal and the IMS core network.

Abstract: A security service control method and a WLAN terminal are provided, and the method includes: stopping a WPI service between a WLAN terminal and an AP when the WLAN terminal creates a security service of an IP layer and/or a layer above the IP layer, wherein the WPI service comprises: encrypting a data link layer message to be transmitted, and decrypting a received data link layer message. After the WPI service is stopped, when the WLAN terminal cancels the security service of the IP layer and/or the layer above the IP layer, the WLAN terminal completes processes of removing association, association, user authentication and key negotiation in turn with the WLAN AP, and uses a session key obtained through the key negotiation to recover the WPI service. The calculating resources can be saved by using the present invention.

Abstract: The present invention discloses a method for establishing a security association among WAPI stations in an ad-hoc network, and the method comprises: when a security association between two stations in the ad-hoc network is to be established, one station STA2 serving as an authenticator entity, another station STA1 serving as an authentication supplicant entity, the station STA2 which serves as the authenticator entity initiating an authentication negotiation to the station STA1 which serves as the authentication supplicant entity, and after completing a unicast key negotiation, the station STA1 and the station STA2 carrying out a multicast key negotiation, and the establishment of the security association being finished after multicast session keys of the station STA1 and the station STA2 are notified successfully in said multicast key negotiation process.

Abstract: A method and system for updating and using a digital certificate, and the method comprises: a first terminal establishing a secure link with an access point and using the secure link to send a certificate updating request to the access point, where the certificate updating request includes a digital certificate to be updated which is currently used by the first terminal; and the access point sending the digital certificate to be updated to a local Authentication Service Unit which issues the certificate to be updated; and the local Authentication Service Unit which issues the digital certificate to be updated verifying the digital certificate to be updated, and after the digital certificate is verified to be valid, a local Authentication Service Unit corresponding to the access point generating a new digital certificate of the first terminal and sending the new digital certificate to the first terminal through the access point.