Key derivation method, communication system, communication terminal, and communication device

Abstract

An object is to provide a key generation method capable of maintaining a high security level in each of sliced networks when network slicing is applied to a core network. A key generation method according to this disclosure specifies network slice identification information indicating a network slice system that provides a service to be used by a communication terminal ( 50 ) among a plurality of network slice systems included in a core network ( 10 ) and, using the network slice identification information, generates a service key to be used for security processing in the network slice system indicated by the network slice identification information.

1 . (canceled) 
     
     
         2 . A key derivation method in a communication terminal that communicates with a core network, the key derivation method comprising:
 deriving a key for each of a plurality of network slices included in the core network.   
     
     
         3 . The key derivation method according to  claim 1 , further comprising:
 deriving a common key common to the plurality of network slices.   
     
     
         4 . The key derivation method according to  claim 3 , wherein both the key for each of the plurality of network slices and the common key are derived from one master key. 
     
     
         5 . The key derivation method according to  claim 3 , wherein the common key is for a control plane. 
     
     
         6 . The key derivation method according to  claim 3 , wherein a key for integrity assurance processing and a key for encryption processing are derived from the common key. 
     
     
         7 . The key derivation method according to  claim 2 , wherein the key for each of the plurality of network slices is for a user plane. 
     
     
         8 . The key derivation method according to  claim 2 , wherein a key for integrity assurance processing and a key for encryption processing are derived from the key for each of the plurality of network slices. 
     
     
         9 . A communication system comprising:
 a core network including a plurality of network slices; and   a communication device,   wherein the communication device derives a key for each of the plurality of network slices.   
     
     
         10 . The communication system according to  claim 9 , wherein the communication device derives a common key common to the plurality of network slices in addition to the key for each of the plurality of network slices. 
     
     
         11 . The communication system according to  claim 10 , further comprising:
 a node device configured to have a master key,   wherein both the key for each of the plurality of network slices and the common key are derived from the master key.   
     
     
         12 . The communication system according to  claim 10 , wherein the common key is for a control plane. 
     
     
         13 . The communication system according to  claim 10 , wherein a key for integrity assurance processing and a key for encryption processing are derived from the common key. 
     
     
         14 . The communication system according to  claim 9 , wherein the key for each of the plurality of network slices is for a user plane. 
     
     
         15 . The communication system according to  claim 9 , wherein a key for integrity assurance processing and a key for encryption processing are derived from the key for each of the plurality of network slices. 
     
     
         16 . A communication terminal comprising:
 at least one memory storing instructions, and   at least one processor configured to execute the instructions to;   communicate with a plurality of network slices included in a core network through a wireless network; and   derive a key for each of the plurality of network slices.   
     
     
         17 . The communication terminal according to  claim 16 , wherein the at least one processor is further configured to execute the instructions to derive a common key common to the plurality of network slices in addition to the key for each of the plurality of network slices. 
     
     
         18 . The communication terminal according to  claim 17 , further the at least one processor is further configured to execute the instructions to control a master key,
 wherein both the key for each of the plurality of network slices and the common key are derived from the master key.   
     
     
         19 . The communication terminal according to  claim 17 , wherein the common key is for a control plane. 
     
     
         20 . The communication terminal according to  claim 17 , wherein a key for integrity assurance processing and a key for encryption processing are derived from the common key. 
     
     
         21 . The communication terminal according to  claim 16 , wherein the key for each of the plurality of network slices is for a user plane. 
     
     
         22 - 28 . (canceled)