Devices and method for mtc group key management

Abstract

In order to improve security upon distributing a group key, there is provided a gateway ( 20 ) to a core network for a group of MTC devices ( 10 _ 1 - 10 _ n ) communicating with the core network. The gateway ( 20 ) protects confidentiality and integrity of a group key, and distributes the protected group key to each of the MTC devices ( 10 _ 1 - 10 _ n ). The protection is performed by using: a key (Kgr) that is preliminarily shared between the gateway ( 20 ) and each of the MTC devices ( 10 _ 1 - 10 _ n ), and that is used for the gateway ( 20 ) to authenticate each of the MTC devices ( 10 _ 1 - 10 _ n ) as a member of the group; or a key (K_iwf) that is shared between an MTC-IWF ( 50 ) and each of the MTC devices ( 10 _ 1 - 10 _ n ), and that is used to derive temporary keys for securely conducting individual communication between the MTC-IWF ( 50 ) and each of the MTC devices ( 10 _ 1 - 10 _ n ).

1 . A network node comprising:
 a memory storing instructions; and   a processor configured to process the instructions to:   receive key information from a server in response to a request to the server, generate, based on the key information, a group key shared by a group of User Equipment (UE)s, and   send a group identification (ID), the group key, and an identifier of the group key toward the group of UEs, wherein the group key is encrypted.   
     
     
         2 . The network node as claimed in  claim 1 , wherein the processor is configured to process the instructions to further: update the group key if a group member is removed from the group of UEs. 
     
     
         3 . A method of a network node, the method comprising:
 receiving key information from a server in response to a request to the server;   generating, based on the key information, a group key shared by a group of User Equipment (UE)s; and   sending a group identification (ID), the group key, and an identifier of the group key toward the group of the UEs, wherein the group key is encrypted.   
     
     
         4 . The method as claimed in  claim 3 , further comprising: updating the group key if a group member is removed from the group of UEs. 
     
     
         5 . A User Equipment (UE) comprising:
 a memory storing instructions; and   a processor configured to process the instructions to:   form a group with other UEs,   receive, from a network node, a group identification (ID), a group key, and an identifier of the group key, wherein the group key is encrypted, and share the group key with the other UEs.   
     
     
         6 . The UE as claimed in  claim 5 , wherein the group key is updated if a group member is removed from the group., 
     
     
         7 . A method of a User Equipment (UE), the method comprising:
 forming a group with other UEs;   receiving, from a network node, a group identification (ID), a group key, and an identifier of the group key, wherein the group key is encrypted; and   sharing the group key with the other UEs.   
     
     
         8 . The method as claimed in  claim 7 , wherein the group key is updated if a group member is removed from the group.