# US 10,375,031 B2 · Ultra dense network security architecture method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,375,031 B2 - Document ID: US10375031B2 - Status: Granted - Kind: B2 - Application number: 15/213,266 - Filed: 2016-07-18 - Published: 2017-01-26 - Granted: 2019-08-06 - Earliest claimed: 2015-07-24 - Assignees: Futurewei Technologies, Inc. - Applicants: Futurewei Technologies, Inc. - Inventors: Ahmad Shawky Muhanna; Zhibi Wang; Jiangsheng Wang - Web page: https://patentgrep.com/patent/US10375031B2 ## CPC - H04L 63/0428: {wherein the data content is protected, e.g. by encrypting or encapsulating the payload} - H04L 63/065: {for group communications (cryptographic mechanisms or cryptographic arrangements for key management involving conference or group key H04L9/0833)} - H04L 63/083: {using passwords (cryptographic mechanisms or cryptographic arrangements for entity authentication using a predetermined code H04L9/3226)} - H04W 12/04: Key management, e.g. using generic bootstrapping architecture [GBA] - H04W 12/06: Authentication - 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 method for establishing a trust relationship in an ultra dense network is provided. The method comprises receiving, by a user equipment (UE), a reconfiguration request from a macrocell; deriving, by the UE, a user plane encryption key according to information in the reconfiguration request; transmitting, by the UE, a first user plane signaling message to a first microcell in a group of microcells when the UE is attached to the first microcell; and transmitting, by the UE, a second user plane signaling message to a second microcell in the group of microcells when the UE is attached to the second microcell, wherein the first user plane signaling message and the second user plane signaling message are both encrypted according to the user plane encryption key. ## Claims ### Claim 1 A method for establishing a trust relationship in an ultra dense network, the method comprising: receiving, by a user equipment (UE), a reconfiguration request from a macrocell that includes a unique counter that is assigned to a group of microcells; encrypting, by the UE, a first user plane signaling message and a second user plane signaling message using the same user plane encryption key, wherein the user plane encryption key is derived in accordance with the unique counter; transmitting, by the UE, the first user plane signaling message to a first microcell in the group of microcells during a first period in which the UE is communicatively coupled to the first microcell; and transmitting, by the UE, the second user plane signaling message to a second microcell in the group of microcells during a second period in which the UE is communicatively coupled to the second microcell. ### Claim 2 (depends on 1) The method of claim 1, wherein the reconfiguration request includes an algorithm to be used by the UE for deriving the user plane encryption key, and wherein the unique counter is used as an input to the algorithm. ### Claim 3 (depends on 1) The method of claim 1, further comprising: deriving a radio resource control (RRC) encryption key (KRRCenc) according to the user plane encryption key; and transmitting an RRC message to the first microcell, wherein signaling in the RRC message is encrypted according to KRRCenc. ### Claim 4 (depends on 1) The method of claim 1, further comprising: deriving a radio resource control (RRC) integrity key (KRRCint) according to the user plane encryption key; receiving an RRC message from the first microcell; and verifying the integrity of the RRC message according to KRRCint. ### Claim 5 (depends on 1) The method of claim 1, wherein the UE receives an identity of the group of microcells from at least one of: the first microcell; the second microcell; and a macrocell associated with the first microcell and the second microcell. ### Claim 6 A user equipment (UE) comprising: a processor; and a non-transitory computer readable storage medium storing programming for execution by the processor, the programming including instructions that when executed by the processor cause the UE to: receive a reconfiguration request from a macrocell that includes a unique counter that is assigned to a group of microcells; encrypt a first user plane signaling message and a second user plane signaling message using the same user plane encryption key, wherein the user plane encryption key is derived in accordance with the unique counter; transmit the first user plane signaling message to a first microcell in the group of microcells during a first period in which the UE is communicatively coupled to the first microcell; and transmit the second user plane signaling message to a second microcell in the group of microcells during a first period in which the UE is communicatively coupled to the second microcell. ### Claim 7 (depends on 6) The UE of claim 6, wherein the reconfiguration request includes an algorithm to be used by the UE for deriving the user plane encryption key, and wherein the unique counter is used as an input to the algorithm. ### Claim 8 (depends on 6) The UE of claim 6, wherein the programming further includes instructions to: derive a radio resource control (RRC) encryption key (KRRCenc) according to the user plane encryption key; and transmit an RRC message to the first microcell, wherein signaling in the RRC message is encrypted according to KRRCenc. ### Claim 9 (depends on 6) The UE of claim 6, wherein the programming further includes instructions to: derive a radio resource control (RRC) integrity key (KRRCint) according to the user plane encryption key; receive an RRC message from the first microcell; and verify the integrity of the RRC message according to KRRCint. ### Claim 10 (depends on 6) The UE of claim 6, wherein the UE receives an identity of the group of microcells from at least one of: the first microcell; the second microcell; and a macrocell associated with the first microcell and the second microcell. ### Claim 11 A computer program product comprising a non-transitory computer readable storage medium storing programming, the programming when executed includes instructions to: receive a reconfiguration request from a macrocell that includes a unique counter that is assigned to a group of microcells; encrypt a first user plane signaling message and a second user plane signaling message using the same a user plane encryption key, wherein the user plane encryption key is derived in accordance with the unique counter; transmit the first user plane signaling message to a first microcell in the group of microcells during a first period in which a user equipment (UE) is communicatively coupled to the first microcell; and transmit the second user plane signaling message to a second microcell in the group of microcells during a first period in which the UE is communicatively coupled to the second microcell. ### Claim 12 (depends on 11) The computer program product of claim 11, wherein the reconfiguration request includes an algorithm to be used by the UE for deriving the user plane encryption key, and wherein the unique counter is used as an input to the algorithm. ### Claim 13 (depends on 11) The computer program product of claim 11, wherein the programming further includes instructions to: derive a radio resource control (RRC) encryption key (KRRCenc) according to the user plane encryption key; and transmit an RRC message to the first microcell, wherein signaling in the RRC message is encrypted according to KRRCenc. ### Claim 14 (depends on 11) The computer program product of claim 11, wherein the programming further includes instructions to: derive a radio resource control (RRC) integrity key (KRRCint) according to the user plane encryption key; receive an RRC message from the first microcell; and verify the integrity of the RRC message according to KRRCint. ### Claim 15 (depends on 11) The computer program product of claim 11, wherein the UE receives an identity of the group of microcells from at least one of: the first microcell; the second microcell; and a macrocell associated with the first microcell and the second microcell. ### Claim 16 A user equipment (UE) comprising: a receiver configured to receive a reconfiguration request from a macrocell that includes a unique counter that is assigned to a group of microcells; one or more processors configured to encrypt a first user plane signaling message and a second user plane signaling message using the same user plane encryption key, wherein the user plane encryption key is derived in accordance with the unique counter; and a transmitter configured to transmit the first user plane signaling message to a first microcell in the group of microcells during a first period in which the UE is communicatively coupled to the first microcell, and to transmit the second user plane signaling message to a second microcell in the group of microcells during a first period in which the UE is communicatively coupled to the second microcell. ### Claim 17 (depends on 16) The UE of claim 16, wherein the information in the reconfiguration request identifies an algorithm to be used by the UE for deriving the user plane encryption key and includes the unique counter to be used as an input into the algorithm.