# US 2018/0026946 A1 · Device and method for establishing security association in communication system

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- Number: US 2018/0026946 A1
- Document ID: US20180026946A1
- Status: Published application
- Kind: A1
- Application number: 15/547,357
- Filed: 2016-01-27
- Published: 2018-01-25
- Earliest claimed: 2015-01-28
- Assignees: Samsung Electronics Co., Ltd.
- Applicants: Samsung Electronics Co., Ltd.
- Inventors: Shijae LEE
- Web page: https://patentgrep.com/patent/US20180026946A1

## CPC

- H04L 63/0281: {Proxies}
- H04L 63/0272: {Virtual private networks}
- H04L 63/20: {for managing network security; network security policies in general (filtering policies H04L63/0227)}
- H04L 67/141: Setup of application sessions (admission control or resource allocation in data switching networks H04L47/70)
- H04L 65/1016: IP multimedia subsystem [IMS]
- H04L 65/1073: Registration or de-registration
- H04L 69/40: for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection (management of faults, events, alarms or notifications in data switching networks H04L41/06)
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)

## Abstract

The present invention relates to a management of a Security Association (SA) between an Internet protocol Multimedia Subsystem (IMS) and a terminal in a communication system. A method of operating a Proxy-Call Session Control Function (P-CSCF) device includes determining a need to establish an SA due to a loss of SA information of a terminal, and transmitting a message for informing the loss of the SA information. In addition, the present invention also includes other exemplary embodiments different from the aforementioned exemplary embodiments.

## Claims

### Claim 1

An apparatus for operating a proxy-call session control function (P-CSCF) server of an internet protocol multimedia subsystem (IMS) in a communication system, the apparatus comprising:
at least one processor configured to determine an establishment of a security association (SA) based on a loss of SA information of a terminal; and
at least one transceiver configured to transmit a message indicating the loss of the SA information.

### Claim 2 (depends on 1)

The apparatus of claim 1, wherein the at least one processor is further configured to determine the establishment of the SA by recognizing the loss of the SA information in the terminal.

### Claim 3 (depends on 2)

The apparatus of claim 2, wherein the at least one processor is further configured to recognize the loss of the SA information in the terminal by determining a non-response regarding a session setup request to the terminal.

### Claim 4 (depends on 1)

The apparatus of claim 1, wherein the at least one processor is further configured to determine the establishment of the SA by receiving a message for informing the establishment of the SA from a serving-call session control function (S-CSCF).

### Claim 5 (depends on 4)

The apparatus of claim 4, wherein the at least one transceiver is further configured to transmit a message indicating the loss of the SA information in the terminal to the S-CSCF.

### Claim 6 (depends on 1)

The apparatus of claim 1, wherein the at least one transceiver is further configured to transmit a session setup request to the terminal after completing the establishment of the SA.

### Claim 7

An apparatus for operating a serving-call session control function (S-CSCF) server of an internal protocol multimedia subsystem (IMS) in a communication system, the apparatus comprising:
at least one processor configured to determine a loss of security association (SA) information of a terminal; and
at least one transceiver configured to transmit a message indicating a need to establish an SA for the terminal.

### Claim 8 (depends on 7)

The apparatus of claim 7, wherein the at least one processor is further configured to determine the loss of the SA information by receiving a message indicating the loss of the SA information in the terminal from a proxy-call session control function (P-CSCF).

### Claim 9 (depends on 7)

The apparatus of claim 7, wherein the at least one transceiver is further configured to transmit a session setup request to the terminal after completing the establishment of the SA of the terminal.

### Claim at position 10

-12. (canceled)

### Claim 13

An apparatus for operating a terminal in a communication system, the apparatus comprising:
at least one transceiver configured to receive a message indicating a loss of security association (SA) information of a terminal; and
at least one processor configured to perform a procedure for establishing the SA.

### Claim 14 (depends on 13)

The apparatus of claim 13, wherein the at least one transceiver is further configured to receive a request for a session setup for an incoming call after completing the establishment of the SA.

### Claim 15

(canceled)

### Claim 16 (depends on 7)

The apparatus of claim 7, wherein the at least one processor is further configured to determine the loss of the SA information by recognizing a failure of the P-CSCF which has established an SA with respect to the terminal.