# US 2020/0288317 A1 · Security protection to prevent unauthorized use of mobile network extenders > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0288317 A1 - Document ID: US20200288317A1 - Status: Published application - Kind: A1 - Application number: 16/291,833 - Filed: 2019-03-04 - Published: 2020-09-10 - Earliest claimed: 2019-03-04 - Assignees: Cisco Technology, Inc. - Applicants: Cisco Technology, Inc. - Inventors: Shivaji Pundlik Diwane; Hungjen Sean Yang; Sundara Paal Rani Thirumalaiappan; Keith Neil Mark Dsouza; Sendilvadivu Ganesan - Web page: https://patentgrep.com/patent/US20200288317A1 ## CPC - H04W 12/08: Access security - H04W 12/0431: Key distribution or pre-distribution; Key agreement - H04W 12/069: using certificates or pre-shared keys - H04W 12/126: Anti-theft arrangements, e.g. protection against subscriber identity module [SIM] cloning - H04W 12/50: Secure pairing of devices - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract In one illustrative example, a mobile network extender has a network interface configured to connect with a host router and a cellular modem configured to provide a wireless link for communications via a cellular mobile network. In a pairing process, the extender may establish a secure encrypted channel with the router via the network interface. In a locking process, the extender may receive information from the router and verify the information. Upon verification, the extender may be set in a locked state in which the extender is logically locked to the router. The extender may also receive and store a secret session key from the router, and permit the router to acquire the extender for communications. In the locked state, the extender may permit or deny subsequent router acquisition upon router reconnection based on verifying, using the secret session key, authentication data received via the network interface. ## Claims ### Claim 1 A method comprising: at a mobile network extender comprising a module which includes a network interface configured to connect with a host router of a private network and a cellular modem configured to provide a wireless link with a base station of a cellular mobile network to provide wide area network access for the private network via the host router, establishing a secure encrypted channel with the host router via the network interface; based on verifying information received from the host router over the secure encrypted channel, setting the extender in a locked state in which the extender is logically locked to the host router; receiving and storing a secret session key from the host router; and permitting the host router to acquire the extender to provide the wide area network access for the private network via the wireless link, wherein, in the locked state, permitting or denying subsequent router acquisition upon router reconnection with the extender is based on verifying, using the secret session key, authentication data received via the network interface. ### Claim 2 (depends on 1) The method of claim 1 wherein, in the locked state, permitting or denying subsequent router acquisition upon router reconnection further comprises: permitting subsequent router acquisition upon router reconnection based on verifying that the authentication data matches the secret session key; and denying subsequent router acquisition upon router reconnection if the authentication data fails to match the secret session key. ### Claim 3 (depends on 1) The method of claim 1, wherein the information comprises extender information, and wherein verifying the information comprises verifying that the extender information matches predetermined extender information associated with the extender. ### Claim 4 (depends on 3) The method of claim 3, wherein the predetermined extender information comprises an International Mobile Equipment Identity (IMEI) of the extender. ### Claim 5 (depends on 1) The method of claim 1, wherein the extender further comprises one or more subscriber identity module (SIM) interfaces, each SIM interface is configured to receive a SIM for use with the cellular modem, and the method further comprises: based on verifying the information received from the host router over the secure encrypted channel, locking the SIM attached to one of the SIM interfaces. ### Claim 6 (depends on 5) The method of claim 5, wherein the information comprises SIM information, and wherein verifying the information comprises verifying that the SIM information matches predetermined SIM information associated with the SIM. ### Claim 7 (depends on 1) The method of claim 1, wherein the network interface of the extender comprises an Ethernet interface for an Ethernet connection to the host router, the method further comprising: receiving, from the host router, one or more messages indicating a request for locking, the one or more messages including the information to be verified. ### Claim 8 (depends on 1) The method of claim 1, further comprising: in response to receiving, from the host router, one or more messages indicating a request for unlocking the host router, setting the extender from the locked state to an unlocked state in which the extender is logically unlocked from the host router; and wherein, in the unlocked state, permitting subsequent router acquisition upon router reconnection with the extender is based on verifying information received via the network interface without verifying authentication data using the secret session key. ### Claim 9 (depends on 1) The method of claim 1, further comprising: in response to receiving, from the host router, one or more messages indicating a request for pairing: exchanging device certificates with the host router via the network interface; establishing trust based on a device certificate of the host router; and establishing the secure encrypted channel with the host router in response to establishing the trust. ### Claim 10 (depends on 1) The method of claim 1, wherein: the extender further comprises one or more subscriber identity module (SIM) interfaces; the information comprises extender information and SIM information; the extender information comprises an International Mobile Equipment Identity (IMEI) which identifies the extender; the SIM information comprises one or more of an International Mobile Subscriber Identity (IMSI), an Integrated Circuit Card ID (ICCID), and a Card Holder Verification 1 (CHV1), which identifies a SIM attached to one of the SIM interfaces; and the method further comprising: based on verifying the information received from the host router over the secure encrypted channel, setting the extender in the locked state and locking a SIM attached to a SIM interface using the CHV1. ### Claim 11 (depends on 5) The method of claim 5, further comprising: in response to receiving, from the host router, one or more messages indicating a request for unlocking: setting the extender from the locked state to an unlocked state in which the extender is logically unlocked; and unlocking the SIM, wherein, in the unlocked state, permitting subsequent router acquisition upon router reconnection with the extender is based on verifying information received over the network interface without verifying authentication data using the secret session key. ### Claim 12 (depends on 1) The method of claim 1, wherein the extender further comprises one or more subscriber identity module (SIM) interfaces, and wherein the secret session key is a function of one or more of a device certificate associated with the host router, an International Mobile Equipment Identity (IMEI) of the extender, an International Mobile Subscriber Identity (IMSI) of a SIM, and an Integrated Circuit Card ID (ICCID) of the SIM. ### Claim 13 A mobile network extender comprising: a module including one or more processors, a network interface configured to connect with a host router of a private network, and a cellular modem with an antenna; the cellular modem with the antenna being configured to provide a wireless link with a base station of a cellular mobile network to provide wide area network access for the private network via the host router; one or more Subscriber Identity Module (SIM) interfaces, each SIM interface being configured to receive a SIM for use with the cellular modem; the one or more processors being configured to: establish a secure encrypted channel with the host router via the network interface; based on verifying information received from the host router over the secure encrypted channel, set the extender in a locked state in which the extender is logically locked to the host router; receive and store a secret session key from the host router; and permit the host router to acquire the extender to provide the wide area network access for the private network via the wireless link, wherein, in the locked state, permitting or denying subsequent router acquisition upon router reconnection with the extender is based on verifying, using the secret session key, authentication data received via the network interface. ### Claim 14 (depends on 13) The mobile network extender of claim 13, wherein the one or more processors are further configured to permit or deny subsequent router acquisition upon router reconnection by: permitting subsequent router acquisition upon router reconnection based on verifying that the information matches the secret session key; and denying subsequent router acquisition upon router reconnection if the information fails to match the secret session key. ### Claim 15 (depends on 13) The mobile network extender of claim 13, wherein: the one or more processors are further configured to, based on verifying the information received from the host router over the secure encrypted channel, set the extender in the locked state and locking the SIM. ### Claim at position 16 16-20. (canceled) ### Claim 21 (depends on 15) The mobile network extender of claim 15, wherein the one or more processors are further configured to: in response to receiving, from the host router, one or more messages indicating a request for unlocking: setting the extender from the locked state to an unlocked state in which the extender is logically unlocked; and unlocking the SIM, wherein, in the unlocked state, permitting subsequent router acquisition upon router reconnection with the extender is based on verifying information received over the network interface without verifying authentication data using the secret session key. ### Claim 22 A computer program product for a mobile network extender, the mobile network extender comprising a module including one or more processors, a network interface to connect with a host router of a private network, and a cellular modem to provide a wireless link with a base station of a cellular mobile network to provide wide area network access for the private network via the host router, the computer program product comprising: a non-transitory computer readable medium; instructions stored in the non-transitory computer readable medium, the instructions being executable on the one or more processors of the extender for: establishing a secure encrypted channel with a host router via the network interface; based on verifying information received from the host router over the secure encrypted channel, setting the extender in a locked state in which the extender is logically locked to the host router; receiving and storing a secret session key from the host router; and permitting the host router to acquire the extender to provide the wide area network access for the private network via the wireless link, wherein, in the locked state, permitting or denying subsequent router acquisition upon router reconnection with the extender is based on verifying, using the secret session key, authentication data received via the network interface. ### Claim 23 (depends on 22) The computer program product of claim 22, wherein the instructions are executable by the one or more processors of the extender further for: in the locked state, permitting or denying subsequent router acquisition upon router reconnection further by: permitting subsequent router acquisition upon router reconnection based on verifying that the authentication data matches the secret session key; and denying subsequent router acquisition upon router reconnection if the authentication data fails to match the secret session key. ### Claim 24 (depends on 22) The computer program product of claim 22, wherein the extender further comprises one or more Subscriber Identity Module (SIM) interfaces, each SIM interface is configured to receive a SIM for use with the cellular modem, and wherein: the information comprises extender information and SIM information; the extender information comprises an International Mobile Equipment Identity (IMEI); the SIM information comprises one or more of an International Mobile Subscriber Identity (IMSI), an Integrated Circuit Card ID (ICCID), and a Card Holder Verification 1 (CHV1); and the instructions are executable on the one or more processors of the extender further for, based on verifying the information received from the host router over the secure encrypted channel, set the extender in the locked state and locking the SIM. ### Claim 25 (depends on 22) The computer program product of claim 22, wherein the extender further comprises one or more Subscriber Identity Module (SIM) interfaces, each SIM interface is configured to receive a SIM for use with the cellular modem, and the instructions are executable on the one or more processors of the extender further for: in response to verifying the information received from the host router over the secure encrypted channel, setting the extender in the locked state and locking the SIM; in response to receiving, from the host router, one or more messages indicating a request for unlocking: setting the extender from the locked state to an unlocked state in which the extender is logically unlocked; and unlocking the SIM.