Multicast broadcast service keys

Patent metadata

Field	Value
Publication number	US-12309580-B2
Application number	US-202117755493-A
Country	US
Kind code	B2
Filing date	May 7, 2021
Priority date	May 7, 2021
Publication date	May 20, 2025
Grant date	May 20, 2025

Abstract

A user equipment (UE) is configured to join a multicast broadcast service (MBS) session. The UE sends, to a network function, a protocol data unit (PDU) modification request comprising a request to join a multicast broadcast service (MBS) session, generates a first key (K MBS-UE ), receives a PDU session modification complete message comprising an encrypted second key (K MBS ) and a key identification (KID) corresponding to the K MBS and decrypts the Kiss using the K MBS-UE .

First claim

What is claimed:

1. A processor of a user equipment (UE) configured to perform operations comprising:
generating, for transmission to a network function, a protocol data unit (PDU) modification request comprising a request to join a multicast broadcast service (MBS) session;
generating a first key (K MBS-UE ), wherein the K MBS-UE is generated using a primary authentication key and a temporary mobile group identification (TMGI), wherein the primary authentication key is established between the UE and a second network function;
receiving a PDU session modification complete message comprising an encrypted second key (K MBS ) and a key identification (KID) corresponding to the K MBS ; and
decrypting the K MBS using the K MBS-UE .

2. The processor of claim 1 , wherein the PDU modification request comprises an MBS session identification of the MBS session that the UE is requesting to join.

3. The processor of claim 1 , wherein at least one of the K MBs and the KID is used by the UE to decrypt MBS session data.

4. The processor of claim 1 , wherein the K MBS is used to derive session keys for encrypting the MBS session data.

5. One or more processors of a first network function configured to perform operations comprising:
receiving an indication that a user equipment (UE) is requesting to join a multicast broadcast service (MBS) session;
generating, in response to receiving the indication, a MBS key request to be transmitted a second network function;
receiving, in response to the MBS key request, an MBS key response comprising a first key (K MBS-UE ) from the second network function, wherein the first key is generated independently by both the second network function and the UE;
receiving, from a third network function, information related to the MBS session, wherein the information comprises a second key (K MBS ) and a key identification (KID) corresponding to the K MBS ; and
generating, for transmission to the UE, a PDU session modification complete message comprising the K MBS and the KID, wherein at least the K MBS is encrypted using the K MBS-UE .

6. The one or more processors of the first network function of claim 5 , wherein the first network function comprises an access and mobility management function (AMF).

7. The one or more processors of the first network function of claim 5 , wherein at least one of the K MBs and the KID is used to decrypt MBS session data and the K MBS is used to derive session keys for encrypting the MBS session data.

8. The one or more processors of the first network function of claim 5 , wherein the second network function comprises an authentication server function (AUSF).

9. The one or more processors of the first network function of claim 5 , wherein the third network function comprises a session management function (SMF).

10. The one or more processors of the first network function of claim 5 , wherein the indication comprises a PDU session modification request by the UE.

11. A method, comprising:
at a user equipment (UE):
sending a protocol data unit (PDU) modification request comprising a request to join a multicast broadcast service (MBS) session;
generating a first key (K MBS-UE ), wherein the K MBS-UE is generated using a primary authentication key and a temporary mobile group identification (TMGI), wherein the primary authentication key is established between the UE and a second network function;
receiving a PDU session modification complete message comprising an encrypted second key (K MBS ) and a key identification (KID) corresponding to the K MBS , and decrypting the K MBS using the K MBS-UE .

12. The method of claim 11 , wherein the PDU modification request comprises an MBS session identification of the MBS session that the UE is requesting to join.

13. The method of claim 11 , wherein at least one of the K MBs and the KID is used by the UE to decrypt MBS session data.

14. The method of claim 11 , wherein the K MBS is used to derive session keys for encrypting the MBS session data.

Assignees

• Apple Inc

Inventors

• Guo Shu
• Zhang Dawei
• Xu Fangli
• Hu Haijing
• Liang Huarui
• Chen Lanpeng
• Qiao Xiaoyu
• Chen Yuqin

Classifications

• H04W4/06

  Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services · CPC title

• H04W12/0431

  Key distribution or pre-distribution; Key agreement · CPC title

• H04W12/76

  Group identity · CPC title

• H04W12/033

  of the user plane, e.g. user's traffic · CPC title

• H04W12/0433

  Key management protocols · CPC title