Call handover between cellular communication system nodes that support different security contexts
AssigneeTelefonaktiebolaget LM Ericsson (publ)
InventorsKarl Norrman, Monica Wifvesson
Life of this patent
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Abstract
In the context of facilitating a circuit switched to packet switched handover of a call in a cellular communication system, a first node (e.g., packet switched target node) generates a security context for a client whose call is being handed over. This involves the first node receiving at least one cryptographic key from a second node (e.g., a circuit switched node supporting the existing connection) and receiving identities of security algorithms supported by the client from a third node (e.g., a packet switched node supporting the existing connection); The first node uses the at least one cryptographic key and the identities to generate the security context for the client.
Claims20
A method of operating a first node to generate a security context for a client in a cellular communication system, wherein the first node comprises processing circuitry, the method comprising:
- the first node performing, as part of a handover in the cellular communication system:
- receiving at least one cryptographic key from a second node;
- receiving identities of security algorithms supported by the client from a third node;
- using the at least one cryptographic key and the identities to generate the security context for the client;
- and
- using the generated security context to, at least in part, control security-related signaling between the client and the cellular communication system,
- wherein the first node is a target packet switched node, the third node is a source packet switched node, and the second node is a source circuit switched node.
A method of operating first and second, nodes in a cellular communication system, the method operating to generate a security context as part of a process of handing over support of a client from the second node to the first node, wherein the first and second nodes each comprise processing circuitry, the method comprising:
- the second node generating at least one new cryptographic key from at least one existing key associated with the client and a nonce generated by the second node;
- the second node communicating the at least one new cryptographic key to the first node;
- the first node receiving identities of security algorithms supported by the client from a third node;
- the first node using the at least one new cryptographic key and the identities to generate the security context for the client;
- and
- using the generated security context to, at least in part, control security-related signaling between the client and the cellular communication system,
- wherein the first node is a target packet switched node, the third node is a source packet switched node, and the second node is a source circuit switched node.
An apparatus for operating a first node to generate a security context for a client in a cellular communication system, the apparatus comprising:
- circuitry configured to receive at least one cryptographic key from a second node;
- circuitry configured to receive identities of security algorithms supported by the client from a third node;
- circuitry configured to use, as part of a handover in the cellular communication system, the at least one cryptographic key and the identities to generate the security context for the client;
- and
- circuitry configured to use the generated security context to, at least in part, control security-related signaling between the client and cellular communication system,
- wherein the first node is a target packet switched node, the third node is a source packet switched node, and the second node is a source circuity switched node.
An apparatus for operating first and second nodes in a cellular communication system, the apparatus operating to generate a security context as part of a process of handing over support of a client from the second node to the first node, the apparatus comprising:
- second node circuitry configured to generate at least one new cryptographic key from at least one existing key associated with the client and a nonce generated by the second node;
- second node circuitry configured to communicate the at least one new cryptographic key to the first node;
- first node circuitry configured to receive identities of security algorithms supported by the client from a third node;
- first node circuitry configured to use the at least one new cryptographic key and the identities to generate the security context for the client;
- and
- circuitry configured to use the generated security context to, at least in part, control security-related signaling between the client and the cellular communication system,
- wherein the first node is a target packet switched node, the third node is a source packet switched node, and the second node is a source circuity switched node.
Dependencies are inferred from the claim text.