5g paging message integrity protection method and system

Abstract

The application discloses a 5G paging message integrity protection method and system, the method comprises the following steps: receiving and saving the user terminal configuration / user subscription configuration message sent by a business operation support system, wherein the user terminal configuration / user subscription configuration message contains a public key in a system master key pair; receiving the paging message sent by a base station device, wherein the paging message contains base station signature information; verifying the validity of the base station signature information by using the public key, and receiving or rejecting the paging message based on the verification result. The application can enable the terminal device to defend against security risks such as fake base stations, man-in-the-middle attacks, or paging channel hijacking.

Description

Technical Field

[0001] This invention relates to the field of network security technology, and in particular to a method and system for protecting the integrity of 5G paging messages. Background Technology

[0002] Mobile communication network services have become widely used in people's daily lives due to their mobility and convenience. With the large-scale deployment of 5G mobile communication networks, more and more people are starting to use 5G network services. While enjoying the convenience brought by mobile communication networks, hostile actors are increasingly becoming a serious problem by using illegal relay devices or fake base stations to eavesdrop on wireless air interface communications and steal users' identity, location, and privacy information.

[0003] Due to the open nature of mobile communication air interfaces, adversaries can deploy fake base station equipment or relay attack equipment in specific 4G / 5G network environments. By tampering with or forging paging messages sent by legitimate base stations, they can mislead terminal devices into connecting to illegal base stations, resulting in the leakage of sensitive user information, such as identity and location. Furthermore, adversaries can use fake base stations or relay equipment to send false paging messages at higher power on specific paging channels, preventing terminal devices from receiving normal paging messages (paging channel hijacking), thus preventing idle terminal devices from receiving important information (incoming calls, SMS messages, and other downlink services). These attacks can pose serious threats to high-security user / network services, making defense against such attacks a crucial issue. To prevent attacks from eavesdropping on or disrupting information transmitted over the air interface, mobile networks have implemented air interface security protection mechanisms. Once activated, these mechanisms ensure the confidentiality and integrity of signaling and user data transmitted by terminals and base station equipment.

[0004] However, current security mechanisms have some security flaws. Specifically, existing wireless air interface information security protection requires that the terminal and network authentication be completed after the RRC connection is established before negotiating air interface security protection keys and activating air interface signaling plane and user plane security protection. Furthermore, when there is no service data interaction on the air interface, the terminal device needs to disconnect the RRC connection and enter an idle state to reduce battery consumption. In the idle state, if downlink service data (incoming calls, SMS, etc.) occurs, the network side notifies the user terminal via paging messages, and the terminal device establishes an RRC connection with the network to receive downlink service data. However, the paging process generally occurs in the idle state, and the air interface is without any security protection at this time. This allows attackers to use fake base stations / relay devices to send false paging information for attacks. Summary of the Invention

[0005] To overcome the above problems, this invention discloses a 5G paging message integrity protection method and system, which enables terminal devices to verify whether the paging message was sent from a legitimate base station device and whether the paging message has been tampered with when they receive a paging message, thereby defending against security risks such as fake base stations, man-in-the-middle attacks, or paging channel hijacking.

[0006] A 5G paging message integrity protection method, applied to terminal equipment, includes the following steps:

[0007] Receive and save user terminal configuration / user subscription configuration messages sent by the business operation support system, wherein the user terminal configuration / user subscription configuration messages contain the public key in the system master key pair, and the system master key pair is generated by the key distribution management center;

[0008] The system receives a paging message sent by a base station device. The paging message includes paging parameters, a timestamp, a globally unique identifier of the base station device, and base station signature information. The base station signature information is obtained by the base station device signing the paging parameters, timestamp, and globally unique identifier of the base station device using a signature key and the public key in the system master key pair. The signature key is generated by the key distribution management center based on the private key, the globally unique identifier of the base station device, and a freshness factor.

[0009] The public key is used to verify the validity of the base station signature information, and based on the verification result, the response to the paging message is accepted or rejected.

[0010] Furthermore, the method for generating the system master key includes the SM9 key generation algorithm.

[0011] Further, the step of the base station device obtaining the signature key includes:

[0012] The base station equipment sends a signature key request message to the key distribution management center. The signature key request message contains the globally unique identifier of the base station equipment and a freshness factor.

[0013] The key distribution management center uses the SM9 cryptographic algorithm and generates the signature key based on the globally unique identifier of the base station equipment, the freshness factor, and the private key in the system master key pair.

[0014] The key distribution management center sends a signature key response message to the base station equipment. The signature key response message includes the base station equipment signature key, the public key in the system master key pair, and the key generation period.

[0015] or,

[0016] The network management system sends a base station signature key request message to the key distribution management center. The base station signature key request message contains a list of globally unique identifiers of base station equipment in the entire network system and a freshness factor.

[0017] The key distribution management center uses the SM9 cryptographic algorithm and, based on the private key and the globally unique identifiers of base station equipment in the list of globally unique identifiers of base station equipment, generates the signature key for each base station identifier in the list and determines the key lifespan.

[0018] The key distribution management center sends a signature key response message to the network management system. The signature key response message includes the signature key list, the public key in the system master key pair, the key lifespan, and the list of globally unique identifiers for base station equipment.

[0019] The network management system sends a base station configuration device message to the base station device. The base station configuration device message includes the signature key, the public key in the system master key pair, and the key lifespan.

[0020] Furthermore, the paging parameters include: user temporary identifier or user identifier, ETWS earthquake and tsunami warning system information, and paging reason.

[0021] Furthermore, after refusing to respond to the paging message, an alarm indicating that the paging message integrity verification has failed is generated.

[0022] A storage medium storing a computer program, wherein the computer program is configured to execute any of the methods described above at runtime.

[0023] A 5G paging message integrity protection terminal device, comprising:

[0024] The first receiving module is used to receive and save user terminal configuration / user subscription configuration messages sent by the business operation support system, wherein the user terminal configuration / user subscription configuration messages contain the public key in the system master key pair, and the system master key pair is generated by the key distribution management center;

[0025] The second receiving module is used to receive paging messages sent by the base station equipment. The paging message includes paging parameters, timestamp, global unique identifier of the base station equipment, and base station signature information. The base station signature information is obtained by the base station equipment signing the paging parameters, timestamp, and global unique identifier of the base station equipment using a signature key and the public key in the system master key pair. The signature key is generated by the key distribution management center based on the private key, freshness factor, and global unique identifier of the base station equipment.

[0026] The verification module is used to verify the validity of the base station signature information using the public key and the SM9 digital signature verification algorithm, and to allow or deny the response to the paging message based on the verification result.

[0027] A 5G paging message integrity protection system includes:

[0028] The key distribution management center is used to generate the system master key pair; and to generate a signature key based on the private key in the master key pair, the globally unique identifier of the base station equipment, and the freshness factor.

[0029] The business operation support system is used to send user terminal configuration / user subscription configuration messages, which include the public key and key generation period in the system master key pair.

[0030] The base station equipment is used to sign paging parameters, timestamps, and the globally unique identifier of the base station equipment using a signature key and the public key in the system master key pair to obtain base station signature information; and to send a paging message, wherein the paging message includes paging parameters, timestamps, the globally unique identifier of the base station equipment, and base station signature information;

[0031] The terminal device is used to receive and store user terminal configuration / user subscription configuration messages sent by the business operation support system; receive paging messages sent by the base station device; verify the validity of the base station signature information using the public key; and allow or refuse to respond to the paging message based on the verification result.

[0032] Furthermore, the system also includes:

[0033] The network management system is used to send a base station signature key request message to the key distribution management center and a base station configuration device message to the base station device; wherein, the base station signature key request message contains a globally unique list of base station devices in the entire network system and a freshness factor, and the base station configuration device message contains the signature key, the public key in the system master key pair, and the key lifespan.

[0034] Compared with the prior art, the present invention has at least the following advantages:

[0035] 1) Enable terminals to verify the authenticity and integrity of paging messages sent by base stations, and defend against fake base stations using forged paging messages for illegal location purposes;

[0036] 2) It can defend against man-in-the-middle tampering with paging messages and deceiving end users;

[0037] 3) Avoid introducing device certificate management infrastructure to reduce system implementation complexity and cost;

[0038] 4) Avoid including base station certificates in air interface paging messages to reduce air interface signaling overhead; Attached Figure Description

[0039] Figure 1 Framework diagram of an identifier-based mobile network paging message protection system.

[0040] Figure 2 A flowchart of an identifier-based mobile network paging message protection method. Detailed Implementation

[0041] The technical solutions in the embodiments of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely specific embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] The paging message integrity protection system of the present invention, such as Figure 1 As shown, the public key from the mobile network system master key pair is pre-installed in the terminal device or the terminal USIM card. Before sending a paging message, the base station device generates a paging message signature using its own signature key, the public key from the system master key pair, and the SM9 digital signature generation algorithm, and appends it to the end of the paging message. Upon receiving the paging message, the user terminal device first verifies the validity of the base station's paging message signature using the public key from the system master key pair and the SM9 digital signature verification algorithm. If the verification fails, the paging message is ignored, and access to the base station device is denied. This prevents adversaries from deceiving the terminal device by broadcasting false paging messages.

[0043] This invention enhances device functionality and expands the content of paging messages. The base station equipment needs to add its signature and timestamp to the paging message. Furthermore, the user terminal equipment's functionality needs to be enhanced by pre-installing the public key from the mobile network system master key pair. The terminal equipment uses the public key from the system master key pair and the SM9 digital signature verification algorithm to verify the validity of the base station equipment signature contained in the received paging message. If the message signature verification fails, the terminal equipment ignores the paging message and refuses access to the base station equipment. By adding base station signature information to the paging message, the authenticity and integrity of the paging message are protected. Based on this idea, this invention proposes a specific implementation scheme.

[0044] This invention enhances mobile networks by introducing a Key Management and Distribution Center (KMC) function. This function uses the SM9 algorithm to generate a system master key public-private key pair and provides the public key to the user terminal. Additionally, it generates a base station device signature key based on the base station equipment identifier (BID), the private key from the system master key pair, and the SM9 algorithm, and provides it to the base station equipment. The base station equipment uses its own signature key, the public key from the system master key pair, and the SM9 digital signature generation algorithm to generate a base station signature (sigBS) based on existing parameters, timestamps, and the base station equipment ID of the paging message or cluster paging message. Existing paging messages or cluster paging messages are extended by adding timestamps, the base station equipment ID, and the base station equipment's signature information (sigBS). The public key from the system master key pair is pre-installed in the user terminal equipment or USIM card. Upon receiving a paging message or cluster paging message, the user terminal equipment uses the public key from the system master key pair and the SM9 digital signature verification algorithm to verify the validity of the base station signature (sigBS) contained in the paging message or cluster paging message. If the signature is valid, the user terminal equipment responds to the paging message and continues normal network access. If the signature verification fails, the paging message is ignored, a paging message indicating signature verification failure is generated, and access to the base station equipment is refused in response to the paging message.

[0045] The paging message integrity protection method of the present invention, such as Figure 2 As shown, it mainly includes:

[0046] (1) The Key Distribution Management Center (KMC) uses the SM9 key generation algorithm to generate the system master key public-private key pair PUBkmc and PRIkmc.

[0047] (2) The base station equipment sends a signature key request message to the KMC, which includes the base station equipment’s globally unique identifier eNB / gNBID and freshness factor.

[0048] (3) KMC uses the SM9 digital signature algorithm to generate the base station device signature key PRIbs based on the base station device identifier eNB / gNB ID, freshness factor and private key PRIkmc, and determines the key life cycle.

[0049] (4) KMC sends a signature key response message to the base station equipment, which includes the base station equipment signature key PRIbs, public key PUBkmc, and key lifespan.

[0050] (5) As an alternative to (2)-(4), the network management system OAM sends a base station signature key request message to KMC, which includes a list of globally unique eNB / gNB IDs of base station equipment and a freshness factor.

[0051] (6) As an alternative to (2)-(4), KMC uses the SM9 digital signature algorithm to generate a list of base station device signature keys PRIbs in batches based on the base station device identifier eNB / gNBID and PRIkmc.

[0052] (7) As an alternative to (2)-(4), KMC sends a signature key response message to the network management system OAM, which includes a list of base station equipment signature keys PRIbs, a list of globally unique base station equipment eNB / gNB IDs, public key PUBkmc, and key lifecycle.

[0053] (8) As an alternative to (2)-(4), the network management system OAM sends a base station configuration device message to the base station, which includes the base station device signature key PRIbs, public key PUBkmc, and key lifecycle.

[0054] (9) As an alternative to (2)-(4), the base station sends a base station configuration device response message to the network management system OAM to indicate that the configuration message has been successfully received.

[0055] (10) The base station equipment securely stores the base station equipment signature key PRIbs, public key PUBkmc, and key lifecycle.

[0056] (11) Before the user terminal attaches to the mobile network, the Business Operation Support System (BOSS) sends a user terminal configuration / user subscription configuration message to the legitimate USIM card in the system via offline method. The message includes the public key PUBkmc in the system master key pair. The public key PUBkmc is obtained by the Business Operation Support System (BOSS) sending a public key request to the KMC.

[0057] (12) The user terminal equipment (UE) reads the relevant key parameters from the USIM card through the interface between the UE and the USIM card, and securely saves the public key PUBkmc in the system master key pair.

[0058] (13) The user terminal equipment (UE) replies to the business operation support system (BOSS) with a user terminal configuration / user subscription configuration response message to indicate that the configuration information has been successfully received.

[0059] (14) The base station uses the signature key PRIbs, the public key PUBkmc, and the SM9 digital signature generation algorithm to generate base station signature information signBS from the existing parameters of the paging message, the timestamp, and the globally unique identifier of the base station equipment eNB / gNB ID.

[0060] (15) The base station equipment sends paging messages or cluster paging messages through the wireless air interface, and adds base station message signature (signBS), timestamp (timestamp), and base station equipment global unique identifier (eNB / gNB ID) to the existing parameters.

[0061] (16) When a user terminal device receives a paging message or a cluster paging message, it uses the public key PUBkmc in the system master key pair and the SM9 digital signature verification algorithm to verify the validity of the base station signature signBS contained in the paging message (regenerating the base station signature signBS' based on the existing parameters of the paging message, timestamp, and the globally unique identifier of the base station device eNB / gNB ID, and verifying the signature by comparing the consistency between signBS and signBS'). If the signature verification fails, the user terminal device refuses to respond to or ignores the paging message or cluster paging message, and generates a paging message integrity verification failure alarm.

[0062] In summary, this invention discloses a signature-based paging message security protection method. This solution is applicable to 3G / 4G / 5G and broadband trunking B-TrunC systems, and has the following main features:

[0063] Introducing a Key Distribution Management Center (KMC) into the existing 4G / 5G network architecture. This function generates a system master key public-private key pair PUBkmc and PRIkmc for base station equipment authentication based on the SM9 algorithm.

[0064] KMC uses the SM9 algorithm to generate the base station equipment signature key PRIbs from PRIkmc, the freshness factor, and the globally unique eNB / gNB ID of the base station equipment, and determines the key lifespan.

[0065] KMC sends the base station's signature key PRIbs, public key PUBkmc, and key lifecycle to the base station through a direct interface with the base station or indirectly through the network management system OAM.

[0066] KMC sends the public key PUBkmc from the system master key pair to the user terminal device's USIM card through a direct interface with the user terminal device or indirectly through the business operation support BOSS system.

[0067] The existing paging messages or trunking paging messages are extended to include base station signatures, time errors, and a globally unique eNB / gNB ID for the base station equipment.

[0068] When a base station sends a paging message, it uses the base station's private key and public key PUBkmc to calculate the base station signature information sigBS based on the paging message parameters, time error, and the base station's globally unique eNB / gNB ID, using the SM9 signature algorithm.

[0069] After receiving a paging message, the user terminal device verifies the base station device signature sigBS in the paging message using the public key PUBkmc in the preset system master key pair and the SM9 signature verification algorithm. If the verification is successful, the user terminal device responds to the paging message and accesses the base station according to the normal procedure; otherwise, it refuses to respond to the paging message and generates a paging message verification failure alarm.

[0070] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for protecting the integrity of 5G paging messages, applied to a terminal device, comprising the following steps: Receive and save user terminal configuration / user subscription configuration messages sent by the business operation support system, wherein the user terminal configuration / user subscription configuration messages contain the public key in the system master key pair, and the system master key pair is generated by the key distribution management center using the SM9 key generation algorithm; The system receives a paging message sent by a base station device. The paging message includes paging parameters, a timestamp, a globally unique identifier of the base station device, and base station signature information. The base station signature information is obtained by the base station device using a signature key and the public key in the system master key pair to sign the paging parameters, timestamp, and globally unique identifier of the base station device using the SM9 digital signature generation algorithm. The signature key is generated by the key distribution management center based on the private key in the system master key pair, the globally unique identifier of the base station device, and a freshness factor, using the SM9 cryptographic algorithm. Using the public key, the validity of the base station signature information is verified using the SM9 digital signature verification algorithm, and based on the verification result, the response to the paging message is accepted or rejected. The step of the base station equipment obtaining the signature key includes: The network management system sends a base station signature key request message to the key distribution management center. The base station signature key request message contains a list of globally unique identifiers of base station equipment in the entire network system and a freshness factor. The key distribution management center uses the SM9 cryptographic algorithm and, based on the private key and the globally unique identifiers of base station equipment in the list of globally unique identifiers of base station equipment, generates the signature key for each base station identifier in the list and determines the key lifespan. The key distribution management center sends a signature key response message to the network management system. The signature key response message includes the signature key list, the public key in the system master key pair, the key lifespan, and the list of globally unique identifiers for base station equipment. The network management system sends a base station configuration device message to the base station device. The base station configuration device message includes the signature key, the public key in the system master key pair, and the key lifespan.

2. The method as described in claim 1, characterized in that, The paging parameters include: user temporary identifier or user identifier, ETWS earthquake and tsunami warning system information, and paging reason.

3. The method as described in claim 1, characterized in that, After refusing to respond to the paging message, an alarm indicating that the paging message integrity verification failed is generated.

4. A 5G paging message integrity protection terminal device, comprising: The first receiving module is used to receive and save user terminal configuration / user subscription configuration messages sent by the business operation support system. The user terminal configuration / user subscription configuration messages contain the public key in the system master key pair. The system master key pair is generated by the key distribution management center using the SM9 key generation algorithm. The second receiving module is used to receive paging messages sent by the base station equipment. The paging message includes paging parameters, a timestamp, a globally unique identifier of the base station equipment, and base station signature information. The base station signature information is obtained by the base station equipment using a signature key and the public key in the system master key pair to sign the paging parameters, timestamp, and globally unique identifier of the base station equipment using the SM9 digital signature generation algorithm. The signature key is generated by the key distribution management center based on the private key in the system master key pair, the freshness factor, and the globally unique identifier of the base station equipment using the SM9 cryptographic algorithm. The verification module is used to verify the validity of the base station signature information using the public key and the SM9 digital signature verification algorithm, and to allow or deny the response to the paging message based on the verification result; The step of the base station equipment obtaining the signature key includes: The network management system sends a base station signature key request message to the key distribution management center. The base station signature key request message contains a list of globally unique identifiers of base station equipment in the entire network system and a freshness factor. The key distribution management center uses the SM9 cryptographic algorithm and, based on the private key and the globally unique identifiers of base station equipment in the list of globally unique identifiers of base station equipment, generates the signature key for each base station identifier in the list and determines the key lifespan. The key distribution management center sends a signature key response message to the network management system. The signature key response message includes the signature key list, the public key in the system master key pair, the key lifespan, and the list of globally unique identifiers for base station equipment. The network management system sends a base station configuration device message to the base station device. The base station configuration device message includes the signature key, the public key in the system master key pair, and the key lifespan.

5. A 5G paging message integrity protection system, comprising: The key distribution management center is used to generate the system master key pair using the SM9 key generation algorithm. A signature key is generated based on the private key in the system master key pair, the globally unique identifier of the base station equipment, the freshness factor, and the SM9 cryptographic algorithm. The business operation support system is used to send user terminal configuration / user subscription configuration messages, which include the public key and key generation period in the system master key pair. The base station equipment uses the public key in the signature key and the system master key pair to sign the paging parameters, timestamp, and the globally unique identifier of the base station equipment using the SM9 digital signature generation algorithm to obtain the base station signature information. Send a paging message, which includes paging parameters, a timestamp, a globally unique identifier for the base station equipment, and base station signature information; Terminal equipment is used to receive and store user terminal configuration / user subscription configuration messages sent by the business operation support system; Receive paging messages sent by base station equipment; Using the public key, the validity of the base station signature information is verified using the SM9 digital signature verification algorithm, and based on the verification result, the response to the paging message is allowed or denied. The step of the base station equipment obtaining the signature key includes: The network management system sends a base station signature key request message to the key distribution management center. The base station signature key request message contains a list of globally unique identifiers of base station equipment in the entire network system and a freshness factor. The key distribution management center uses the SM9 cryptographic algorithm and, based on the private key and the globally unique identifiers of base station equipment in the list of globally unique identifiers of base station equipment, generates the signature key for each base station identifier in the list and determines the key lifespan. The key distribution management center sends a signature key response message to the network management system. The signature key response message includes the signature key list, the public key in the system master key pair, the key lifespan, and the list of globally unique identifiers for base station equipment. The network management system sends a base station configuration device message to the base station device. The base station configuration device message includes the signature key, the public key in the system master key pair, and the key lifespan.

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