# US 12,015,707 B2 · Communication method and related product

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- Number: US 12,015,707 B2
- Document ID: US12015707B2
- Status: Granted
- Kind: B2
- Application number: 17/380,961
- Filed: 2021-07-20
- Published: 2021-11-11
- Granted: 2024-06-18
- Earliest claimed: 2019-01-21
- Assignees: Huawei Technologies Co., Ltd.
- Applicants: Huawei Technologies Co., Ltd.
- Inventors: Juan Deng; Chengdong He
- Web page: https://patentgrep.com/patent/US12015707B2

## CPC

- H04L 9/0891: {Revocation or update of secret information, e.g. encryption key update or rekeying}
- H04L 9/321: {involving a third party or a trusted authority}
- H04W 12/041: Key generation or derivation
- H04W 12/0433: Key management protocols
- H04W 60/00: Affiliation to network, e.g. registration; Terminating affiliation with the network, e.g. de-registration
- H04W 60/002: {Registration for requesting network slices}
- H04W 60/04: using triggered events
- H04L 2209/80: Wireless
- H04W 36/12: Reselecting a serving backbone network switching or routing node
- H04W 88/08: Access point devices
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)

## Abstract

A communication method and a related product are provided. The communication method includes: When UE switches from a source slice to a target slice mutually exclusive with the source slice, both the UE and a target AMF serving the target slice can obtain a first AMF key Kamf_new. The first AMF key Kamf_new is different from a second AMF key Kamf, and the second AMF key Kamf is a key of a source AMF serving the source slice. According to the application communication security and effectiveness are significantly improved_in a mutually exclusive slice switching scenario.

## Claims

### Claim 1

A communication method applied to a target access and mobility management function (AMF), the method comprising:
in response to user equipment (UE) switching from a source slice to a target slice mutually exclusive with the source slice, receiving, by the target AMF serving the target slice, a registration request message from the UE,
wherein the registration request message carries network slice selection assistance information (NSSAI) of the target slice requested by the UE;
sending, by the target AMF, a key update service request to an authentication server function (AUSF),
wherein the key update service request carries a key input parameter T1 and/or a key input parameter T2;
receiving, by the target AMF, a response to the key update service sent to the AUSF; and
obtaining, by the target AMF, a first, AMF key, Kamf_new that is different from a second AMF key, Kamf_old,
wherein the Kamf_new is generated based on the key input parameter T1 and/or the key input parameter T2 and the response, and
wherein the Kamf_new is a key of the target AMF, and the Kamf_old is a key of a source AMF serving the source slice.

### Claim 2 (depends on 1)

The communication method according to claim 1, wherein the registration request message further carries a second key update indication that indicates a network side to update an AMF key, and wherein the target AMF obtains the Kamf_new based on the second key update indication.

### Claim 3 (depends on 1)

The communication method according to claim 1,
wherein the response carries a security anchor function (SEAF) key Kseaf_new,
wherein the key input parameter T1 and/or the key input parameter T2 are/is used to generate the Kseaf_new, and
wherein the Kseaf_new is used to generate the Kamf_new.

### Claim 4 (depends on 1)

The communication method according to claim 1, wherein the target AMF obtains the Kamf_new in response to a determination that a locally preset key update condition is met.

### Claim 5 (depends on 1)

The communication method according to claim 1, wherein the response carries a security anchor function (SEAF) key Kseaf_new and a key input parameter T3, wherein the key input parameter T3 is used to generate the Kseaf_new, and wherein the Kseaf_new is used to generate the Kamf_new; and
the method further includes sending, by the target AMF to the UE, a first message that carries the key input parameter T3.

### Claim 6 (depends on 1)

The communication method according to claim 1, wherein the key update service request carries a key input parameter T2 and/or the key input parameter T1, wherein the response carries a security anchor function (SEAF) key Kseaf_new and a key input parameter T3, wherein the key input parameter T3 and T1 and/or T2, are used to generate the Kseaf_new, and wherein the Kseaf_new is used to generate the Kamf_new; and
the method further includes sending, by the target AMF to the UE, a first message that carries the key input parameter T3.

### Claim 7

A communication method applied to a target access and mobility management function (AMF), the method comprising:
in response to user equipment (UE) switching from a source slice to a target slice mutually exclusive with the source slice, receiving, by the target AMF serving the target slice, a registration request message from the UE,
wherein the registration request message carries network slice selection assistance information (NSSAI) of the target slice requested by the UE;
sending, by the target AMF, a key update service request to a security anchor function (SEAF);
wherein the key update service request carries a key input parameter T1 and/or a key input parameter T2;
receiving, by the target AMF, a response from the SEAF to the key update service request,
wherein the response carries a first AMF key, Kamf_new that is different from a second AMF key, Kamf_old,
wherein the Kamf_new is generated based on the key input parameter T1 and/or the key input parameter T2 and the response, and
wherein the Kamf_new is a key of the target AMF, and the Kamf_old is a key of a source AMF serving the source slice; and
obtaining, by the target AMF, the Kamf_new.

### Claim 8 (depends on 7)

The communication method according to claim 7,
wherein the key update service request carries a key input parameter T2 and/or the key input parameter T1, and
wherein the key input parameter T2 and/or the key input parameter T1 are/is used to generate the Kamf_new.

### Claim 9 (depends on 7)

The communication method according to claim 7, wherein the registration request message further carries a second key update indication that indicates a network side to update an AMF key, and wherein the target AMF obtains the Kamf_new based on the second key update indication.

### Claim 10 (depends on 7)

The communication method according to claim 7, wherein the target AMF obtains the Kamf_new in response to a determination that a locally preset key update condition is met.

### Claim 11 (depends on 7)

The communication method according to claim 7, wherein a key input parameter T4 is used to generate the Kamf_new; and
the method further includes sending, by the target AMF to the UE, a first message that carries the key input parameter T4.

### Claim 12 (depends on 7)

The communication method according to claim 7,
wherein a key input parameter T4 and T2 and/or T1 are used to generate the Kamf_new; and
the method further includes sending, by the target AMF to the UE, a first message that carries the key input parameter T4.

### Claim 13

A communication method applied to a target access and mobility management function (AMF), the method comprising:
in response to user equipment (UE) switching from a source slice to a target slice mutually exclusive with the source slice, receiving, by the target AMF serving the target slice, a registration request message from the UE,
wherein the registration request message carries network slice selection assistance information (NSSAI) of the target slice requested by the UE;
sending, by the target AMF, to a slice authentication and authorization server (AAA-S), a message carrying a key parameter indication,
wherein the key parameter indication indicates to the AAA-S to generate a key input parameter T5;
receiving, by the target AMF, the key generation parameter T5 sent by the AAA-S,
wherein the key input parameter T5 is used to obtain a first AMF key, Kamf_new that is different from a second AMF key, Kamf_old, and
wherein the Kamf_new is a key of the target AMF, and the Kamf_old is a key of a source AMF serving the source slice; and
obtaining, by the target AMF, the Kamf_new.

### Claim 14 (depends on 13)

The communication method according to claim 13, wherein a key input parameter T1 and/or a key input parameter T2 are/is further used to generate the Kamf_new.

### Claim 15 (depends on 13)

The communication method according to claim 13, wherein the registration request message further carries a second key update indication that indicates a network side to update an AMF key, and wherein the target AMF obtains the Kamf_new based on the second key update indication.

### Claim 16 (depends on 13)

The communication method according to claim 13, wherein the registration request message carries a key input parameter T1 that is used to generate the Kamf_new.

### Claim 17 (depends on 13)

The communication method according to claim 13, wherein the target AMF obtains the Kamf_new in response to a determination that a locally preset key update condition is met.

### Claim 18 (depends on 13)

The communication method according to claim 13, wherein a key input parameter T4 is used to generate the Kamf_new; and
the method further includes sending, by the target AMF to the UE, a first message that carries the key input parameter T4; or
wherein the key update service request carries a key input parameter T2 and/or a key input parameter T1, wherein a key input parameter T4 and the key input parameter T2 and/or T1 carried in the key update service are used to generate the Kamf_new; and
the method further includes sending, by the target AMF to the UE, a first message that carries the key input parameter T4.