# US 9,882,936 B2 · Methods systems, and computer program products for security protocol selection in internet protocol multimedia subsystem networks > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,882,936 B2 - Document ID: US9882936B2 - Status: Granted - Kind: B2 - Application number: 15/413,562 - Filed: 2017-01-24 - Published: 2017-05-11 - Granted: 2018-01-30 - Earliest claimed: 2014-10-24 - Assignees: AT&T Intellectual Property I, L.P. - Applicants: AT&T Intellectual Property I, L.P. - Inventors: Mohamed Khalil; Arun Chatterjee; Mazen Aladwan; Karl Schlieber - Web page: https://patentgrep.com/patent/US9882936B2 ## CPC - H04L 63/205: {involving negotiation or determination of the one or more network security mechanisms to be used, e.g. by negotiation between the client and the server or between peers or by selection according to the capabilities of the entities involved (negotiation of communication capabilities H04L69/24)} - H04L 65/1016: IP multimedia subsystem [IMS] - H04L 65/1073: Registration or de-registration - H04L 65/1104: Session initiation protocol [SIP] - H04W 12/03: Protecting confidentiality, e.g. by encryption - H04W 12/08: Access security - H04W 60/001: {Registration rejection or failure} - H04W 60/04: using triggered events - 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 includes receiving a first secured registration request message from user equipment at a registration server in an Internet Protocol multimedia subsystem network, the first secured registration request message being secured using a first security protocol, determining at the registration server that the first secured registration request message cannot be decoded using the first security protocol, sending a message from the registration server to the user equipment proposing a second security protocol, and receiving a second secured registration request message from the user equipment at the registration server, the second secured registration request message being secured using the second security protocol. ## Claims ### Claim 1 A system, comprising: a memory that stores instructions; and a processor that executes the instructions to perform operations, the operations comprising: receiving, at a registration server, a security protocol identification message from user equipment, wherein the security protocol identification message identifies a list of security protocols supported by the user equipment, wherein the list of security protocols comprises a first protocol and a second protocol; sending, prior to receiving a first secured registration request message from the user equipment, a first message from the registration server to the user equipment proposing the first protocol; receiving, at the registration server, the first secured registration request message from the user equipment, wherein the first secured registration request message is secured using the first security protocol, wherein the first secured registration request message is received from the user equipment in response to sending the first message from registration server to the user equipment proposing the first protocol; determining, at the registration server, that the first secured registration request message cannot be decoded using the first protocol; sending, to the user equipment, a second message from the registration server proposing the second protocol; and receiving, at the registration server, a second secured registration request message from the user equipment, wherein the second secured registration request message is secured using the second protocol. ### Claim 2 (depends on 1) The system of claim 1, wherein the operations further comprise decoding the second secured registration request message using the second protocol. ### Claim 3 (depends on 2) The system of claim 2, wherein the operations further comprise registering the user equipment with an internet protocol multimedia subsystem network after decoding the second secured registration request message. ### Claim 4 (depends on 1) The system of claim 1, wherein the operations further comprise determining that the second secured registration request message cannot be decoded using the second security protocol. ### Claim 5 (depends on 4) The system of claim 4, wherein the operations further comprise sending, to the user equipment, a third message from the registration server proposing a third protocol. ### Claim 6 (depends on 5) The system of claim 5, wherein the operations further comprise receiving, at the registration server, a third secured registration request message from the user equipment, wherein the third secured registration request message is secured using the third protocol. ### Claim 7 (depends on 6) The system of claim 6, wherein the operations further comprise decoding the third secured registration request message. ### Claim 8 (depends on 7) The system of claim 7, wherein the operations further comprise registering the user equipment with an internet protocol multimedia subsystem network after decoding the third secured registration request message. ### Claim 9 (depends on 1) The system of claim 1, wherein the operations further comprise determining, based on the list of security protocols, that the second protocol is associated with a greater probability of successful registration of the user equipment than a third protocol. ### Claim 10 (depends on 1) The system of claim 1, wherein the operations further comprise sending a disable message to the user equipment to disable functionality in the user equipment for registering the user equipment. ### Claim 11 (depends on 1) The system of claim 1, wherein the operations further comprise determining that the user equipment is infected with a virus if the second secured registration request message cannot be decoded. ### Claim 12 (depends on 1) The system of claim 1, wherein the operations further comprise receiving an additional request to register the user equipment if registration of the user equipment fails. ### Claim 13 A method, comprising: receiving, at a registration server, a security protocol identification message from user equipment, wherein the security protocol identification message identifies a list of security protocols supported by the user equipment, wherein the list of security protocols comprises a first protocol and a second protocol; sending, prior to receiving a first secured registration request message from the user equipment, a first message from the registration server to the user equipment proposing the first protocol; receiving, at the registration server, the first secured registration request message from the user equipment, wherein the first secured registration request message is secured using the first security protocol, wherein the first secured registration request message is received from the user equipment in response to sending the first message from registration server to the user equipment proposing the first protocol; determining, at the registration server, that the first secured registration request message cannot be decoded using the first protocol; sending, to the user equipment, a second message from the registration server proposing the second protocol; and receiving, at the registration server, a second secured registration request message from the user equipment, wherein the second secured registration request message is secured using the second protocol. ### Claim 14 (depends on 13) The method of claim 13, further comprising decoding the second secured registration request message using the second protocol. ### Claim 15 (depends on 14) The method of claim 14, further comprising registering the user equipment with a network after decoding the second secured registration request message. ### Claim 16 (depends on 13) The method of claim 13, further comprising determining, based on the list of security protocols, that the second protocol is associated with a greater probability of successful registration of the user equipment than a third protocol. ### Claim 17 (depends on 13) The method of claim 13, further comprising sending a disable message to the user equipment to disable functionality in the user equipment for registering the user equipment. ### Claim 18 (depends on 13) The method of claim 13, further comprising determining that the user equipment is infected with a virus if the second secured registration request message cannot be decoded. ### Claim 19 (depends on 13) The method of claim 13, further comprising receiving an additional request to register the user equipment if registration of the user equipment fails. ### Claim 20 A non-transitory computer-readable medium comprising instructions, which, when loaded and executed by a processor, cause the processor to perform operations, the operations comprising: receiving, at a registration server, a security protocol identification message from user equipment, wherein the security protocol identification message identifies a list of security protocols supported by the user equipment, wherein the list of security protocols comprises a first protocol and a second protocol; sending, prior to receiving a first secured registration request message from the user equipment, a first message from the registration server to the user equipment proposing the first protocol; receiving, at the registration server, the first secured registration request message from the user equipment, wherein the first secured registration request message is secured using the first security protocol, wherein the first secured registration request message is received from the user equipment in response to sending the first message from registration server to the user equipment proposing the first protocol; determining, at the registration server, that the first secured registration request message cannot be decoded using the first protocol; sending, to the user equipment, a second message from the registration server proposing the second protocol; and receiving, at the registration server, a second secured registration request message from the user equipment, wherein the second secured registration request message is secured using the second protocol.