Authentication server and program

Abstract

An access token is issued only if the authenticator, SIM, is implemented in a specific WD. [Solution] The authentication server includes access means that can access determination information indicating the relationship between line information and a device identifier; acquisition means that, in response to receiving an authentication request including first line information from a wireless device of a mobile communication network, obtain a first device identifier associated with the first line information from the mobile communication network; and processing means that, if the first device identifier does not match the device identifier associated with the first line information in the determination information, determine that authentication of the wireless device is unsuccessful.

Description

Technical Field

[0001] The present disclosure relates to an authentication technology for wireless devices in a mobile communication network.

Background Art

[0002] Non-Patent Document 1 discloses an authentication method also called FIDO (Fast Identity Online) authentication. According to Non-Patent Document 1, a secret key, also called a credential, is stored in an authenticator, and a public key corresponding to the secret key is stored in an authentication server. The authentication server transmits challenge data to the authenticator, and the authenticator generates a signature of the challenge data based on the stored secret key and transmits it to the authentication server. The authentication server verifies the signature with the stored public key to authenticate the authenticator, and thus authenticate the user using the authenticator. A so-called tamper-resistant device is used for the authenticator.

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Wireless devices (WDs) that communicate via mobile communication networks are equipped with an integrated circuit called a subscriber identification module (SIM). The WD accesses the mobile communication network based on information stored in the SIM, which is also referred to as a profile. In the following description, the term SIM refers to a combination of removable SIM cards, embedded SIMs (eSIMs) that cannot be removed from the WD, and embedded general-purpose integrated circuit cards (eUICCs). The eUICC is an integrated circuit configured to allow remote rewriting of its profile. Because SIMs are tamper-resistant devices, they can be used as authenticators for authentication of WDs (or WD users) by an authentication server.

[0005] Each SIM is assigned a SIM identifier to identify it individually. This SIM identifier may be, for example, an Integrated Circuit Card Identifier (ICCID) or an Embedded Identification Document (EID). Furthermore, the SIM stores a subscriber identifier assigned by the mobile network operator for each contract with the subscriber. This subscriber identifier may be, for example, an International Mobile Subscriber Identifier (IMSI). The subscriber identifier is also the identifier associated with the profile file used to access the mobile network. When using a SIM as an authenticator, the SIM can be identified by the SIM identifier, the subscriber identifier, or a combination of both.

[0006] A WD (Working User) can access an Application Server (AS) on a data network (DN), such as the Internet, via a mobile communication network and utilize services provided by the AS. An "access token" may be used when a WD accesses an AS and receives services. An access token may be issued, for example, by an authentication server that authenticated the WD, and may be used to prove to the AS that the WD has the right to use certain services provided by the AS. The WD presents the access token to the AS when accessing the AS and receiving services.

[0007] Currently, WDs are used in the business activities of companies and other organizations. Because WDs used for business purposes access and store confidential information of companies and other organizations, security policies are applied to WDs used for business purposes, such as restricting the access of ASs (Automated Storage Systems).

[0008] An access token can be used to apply a predetermined security policy to a WD (Working Device). For example, an access token conforming to the security policy to be applied to the WD can be stored in an authentication server, and when the authentication server authenticates the WD, the access token can be sent to the WD. However, if the SIM card is of a type that can be attached to and removed from the WD, it becomes possible to access confidential information using a different WD by inserting the SIM card from a WD leased by a company or other entity into another WD.

[0009] Therefore, it may be required that an access token be issued only if the authenticator, which is the SIM, is implemented in a particular WD. [Means for solving the problem]

[0010] According to one aspect of the present disclosure, the authentication server includes access means capable of accessing determination information indicating a relationship between line information and a device identifier; acquisition means for obtaining a first device identifier associated with the first line information from a mobile communication network in response to receiving an authentication request including first line information from a wireless device of a mobile communication network; and processing means for determining that authentication of the wireless device is unsuccessful if the first device identifier does not match a device identifier associated with the first line information in the determination information. [Effects of the Invention]

[0011] According to this disclosure, access tokens can be issued only when the authenticator, which is a SIM, is implemented in a specific WD. [Brief explanation of the drawing]

[0012] [Figure 1] An example system configuration diagram. [Figure 2] A sequence diagram of the process of registering a public key with the authentication server. [Figure 3] Sequence diagram of the authentication process for WD by the authentication server. [Figure 4] A sequence diagram showing the process when a Working Driver (WD) initiates the use of services provided by an AS (Assessment System). [Figure 5] Another sequence diagram of the process of registering a public key with the authentication server. [Figure 6] Another sequence diagram of the authentication process for WD by the authentication server. [Figure 7] A diagram showing an example of an authentication server configuration. [Modes for carrying out the invention]

[0013] The embodiments will be described in detail below with reference to the attached drawings. Note that the following embodiments do not limit the invention as defined in the claims, and not all combinations of features described in the embodiments are essential to the invention. Two or more features from the multiple features described in the embodiments may be arbitrarily combined. Furthermore, identical or similar configurations will be given the same reference numeral, and redundant descriptions will be omitted.

[0014] <First Embodiment> Figure 1 is a system configuration diagram used to describe the embodiment. WD1 includes a SIM 10 and a processing unit 11. WD1 may be a device that is operated by a human, such as a smartphone or tablet, or a device that is not operated by a human, such as a so-called IoT (Internet of Things) device. Note that WD1 is lent to an employee by a company, and therefore the security policy of that company applies to WD1. In the following description, the company that lent WD1 to an employee will be referred to as the "administrator" of WD1.

[0015] SIM10 is an integrated circuit with tamper resistance and stores a profile for accessing the mobile communication network 21. SIM10 further stores the SIM identifier of SIM10 and the subscriber identifier. As described above, the SIM identifier is an ICCID or an EID, and the subscriber identifier can be an IMSI. In the following description, the SIM identifier, the subscriber identifier, or a combination of the SIM identifier and the subscriber identifier is referred to as the "line information" of WD1 or SIM10.

[0016] The processing unit 11 may include one or more processors, an integrated circuit that performs communication processing for accessing the mobile communication network 21, which is also called a modem chip or the like, a non-volatile memory device, and a volatile memory device. The one or more processors execute an operating system (OS) and an application program (APP) stored in the non-volatile memory device.

[0017] The network 2 in FIG. 1 is a general term for the mobile communication network 21 and the DN22 such as the Internet. WD1 can communicate with the authentication server 3 and the AS5 connected to the DN22 via the mobile communication network 21. The authentication server 3 and the AS5 can also be referred to as devices within the DN22. In FIG. 1, the authentication server 3 and the AS5 are shown as devices within the DN22, but one or both of the authentication server 3 and the AS5 may be devices within the mobile communication network 21. Also, a database (DB) 6 is provided in the mobile communication network 21.

[0018] The mobile communication network 21 stores the device identifier and line information of the WD1 obtained from the WD1 that has accessed the mobile communication network 21 in the DB6. The device identifier identifies the hardware of the individual WD1 and can be, for example, an International Mobile Equipment Identity (IMEI).

[0019] AS5 is a device that provides a predetermined service. The authentication server 3 is a device that performs authentication of WD1 and issues an access token to the WD1 when the authentication of the WD1 is successful. The authentication server 3 stores line information, and determination information indicating a device identifier and an access token associated with the line information. The determination information is created, for example, by the administrator of the WD1 and stored in the authentication server 3 in an arbitrary method in advance. The relationship between the line information and the device identifier indicated by the determination information shows the correspondence relationship between SIM10 (corresponding to the line information) and WD1 (corresponding to the device identifier) permitted by the administrator of the WD1. In other words, the determination information is information indicating the WD1 that can use the SIM10.

[0020] In the present embodiment, the SIM10 operates as an authenticator in the authentication by the authentication server 3. In order to enable the authentication by the authentication server 3, the SIM10 generates a secret key (credential) used in the authentication by the authentication server 3 and a public key corresponding to the secret key. The public key generated by the SIM10 is registered in the authentication server 3 in advance.

[0021] Figure 2 is a sequence of processes for registering a public key in the authentication server 3. In S10, the processing unit 11 transmits a registration request to the authentication server 3. Note that information for communicating with the authentication server 3 is stored in the processing unit 11 in advance. The registration request includes line information. The authentication server 3 responds to the registration request and transmits challenge data to the processing unit 11 in S11. The challenge data can be random data.

[0022] In S12, the processing unit 11 outputs challenge data to the SIM 10 and instructs it to generate a key. In S13, the SIM 10 generates a private key and a public key pair, and in S14 stores the private key. Based on the generated private key, the SIM 10 generates signature data for the challenge data, and in S15 outputs the public key and signature data to the processing unit 11. In S16, the processing unit 11 sends the public key and signature data to the authentication server 3. The authentication server 3 verifies the signature data using the public key. If the verification is successful, in S17 the authentication server 3 stores the public key associated with the line information received in S10, and in S18 notifies the processing unit 11 that registration is complete.

[0023] Figure 3 shows the sequence of authentication processing for WD1 by the authentication server 3. In S20, the processing unit 11 sends an authentication request to the authentication server 3. The authentication request includes line information. In response to the authentication request, the authentication server 3 sends an information request to DB6 in S21. The information request includes the line information received in S20. In S22, DB6 sends the device identifier associated with the line information to the authentication server 3. In S23, the authentication server 3 determines whether the device identifier received in S22 matches the device identifier associated with the line information received in S20 in the determination information.

[0024] If the device identifier received from DB6 does not match the device identifier indicated in the judgment information, it means that the SIM10 lent by the administrator is installed in a different WD than the WD1 lent by the administrator. Therefore, if the device identifier received from DB6 does not match the device identifier indicated in the judgment information, the authentication server 3 notifies the processing unit 11 of the authentication failure. This terminates the sequence in Figure 3. In the example in Figure 3, they match, so the authentication server 3 sends challenge data to the processing unit 11 in S24. The challenge data may be random data.

[0025] In S25, the processing unit 11 outputs challenge data to the SIM 10. The SIM 10 generates signature data for the challenge data based on the stored private key and outputs the signature data to the processing unit 11 in S26. In S27, the processing unit 11 sends the signature data to the authentication server 3. In S28, the authentication server 3 verifies the signature data using the public key associated with the line information received in S20. If the verification of the signature data is successful, the authentication server 3 determines that the authentication of WD1 is successful. If the authentication of WD1 is successful, in S29, the authentication server 3 sends the access token associated with the line information received in S20 to the processing unit 11 in the determination information. If the verification is unsuccessful, the authentication server 3 notifies the processing unit 11 of the authentication failure. This completes the sequence in Figure 3.

[0026] The authentication server can determine that authentication for WD1 failed without requesting information from DB6 if the line information received in S20 is not included in the judgment information. Furthermore, the authentication server can also determine that authentication for WD1 failed without requesting information from DB6 if it does not store the public key associated with the line information received in S20.

[0027] Furthermore, in this embodiment, the access token associated with the line information was stored in the authentication server 3 in advance as part of the determination information. However, it is also possible to configure the system so that the access token is not stored in the authentication server 3 in advance. For example, if the authentication server 3 succeeds in verification in S28, it can be configured to send the line information to a predetermined server that stores the access token, obtain the access token associated with the line information from the predetermined server, and send it to the processing unit 11 in S29.

[0028] Figure 4 shows the sequence when WD accesses AS5 to receive services. In S30, processing unit 11 sends a service request to AS5. The service request includes an access token. Based on the access token, AS5 determines the service usage rights that WD1 possesses.

[0029] For example, an access token may contain information indicating the service usage rights of WD1. In this case, AS5 can determine the usage rights of WD1 based on the information indicated by the access token. Alternatively, an access token may be an identifier for accessing information used to determine the service usage rights of WD1. In this case, AS5 can obtain information used to determine the service usage rights of WD1 from a predetermined server by sending the access token to that server.

[0030] With the above configuration, access tokens can be issued only when the authenticator, SIM10, is implemented in a specific WD1.

[0031] <Second Embodiment> Next, the second embodiment will be described, focusing on the differences from the first embodiment. In the first embodiment, encrypted communication such as Hypertext Transfer Protocol Secure (HTTPS) may be used for communication between the processing unit 11 and the authentication server 3. Therefore, the line information transmitted to the authentication server 3 in S10 of Figure 2 and S20 of Figure 3 will be kept confidential even if eavesdropping occurs on the network 2. However, the line information transmitted to the authentication server 3 in S10 of Figure 2 and S20 of Figure 3 is information stored in the SIM 10. Therefore, in the sequences of Figures 2 and 3, the processing unit 11 needs to read the line information from the SIM 10.

[0032] In this case, if a malicious app is running in the processing unit 11, the line information may be misused. Therefore, in this embodiment, the SIM 10, rather than the processing unit 11, performs encrypted communication with the authentication server 3.

[0033] Figure 5 shows the sequence of operations for registering a public key with the authentication server 3 according to this embodiment. In S40, the processing unit 11 sends a registration instruction to the SIM 10. In response to the registration instruction from the processing unit 11, the SIM 10 communicates with the authentication server 3 in S41 and starts the communication key exchange process. The information for communicating with the authentication server 3 is stored in the SIM 10 in advance. Alternatively, the information for communicating with the authentication server 3 is notified by the processing unit 11 in S40.

[0034] The communication key exchange process could be, for example, a Transport Layer Security (TLS) handshake performed over HTTPS. Through the communication key exchange process, SIM10 and authentication server 3 generate a common encryption key (communication key) to be used for encrypting communication. After the communication key is generated, information sent and received between SIM10 and authentication server 3 is encrypted using the generated communication key. In S42, SIM10 sends a registration request including line information to authentication server 3. In response to the registration request, authentication server 3 sends challenge data to SIM10 in S43.

[0035] In S44, SIM10 generates a private key and a public key pair, and in S45 stores the private key. Based on the generated private key, SIM10 generates signature data for the challenge data, and in S46 sends the public key and signature data to the authentication server 3. The authentication server 3 verifies the signature data using the public key. If the verification is successful, in S47, the authentication server 3 stores the public key associated with the line information received in S42, and in S48 notifies SIM10 that registration is complete. In S49, SIM10 notifies the processing unit 11 that registration is complete.

[0036] In communication between SIM10 and authentication server 3, SIM10 performs processing at or above the Transmission Control Protocol (TCP) layer, while processing unit 11 performs processing at or below the Internet Protocol (IP) layer. In this case, TCP packets are sent and received between SIM10 and processing unit 11. Therefore, similar to network 2, processing unit 11 cannot decrypt the encrypted information sent and received between SIM10 and authentication server 3, thereby reducing the risk of leakage of line information.

[0037] Figure 6 shows the sequence of the authentication process according to this embodiment. In S50, the processing unit 11 sends an authentication instruction to the SIM 10. In response to the authentication instruction from the processing unit 11, the SIM 10 communicates with the authentication server 3 in S51 and starts the communication key exchange process. In S52, the SIM 10 sends an authentication request including line information to the authentication server 3. In response to the authentication request, the authentication server 3 sends an information request to the DB6 in S53. The information request includes the line information received in S52. In S54, the DB6 sends the device identifier associated with the line information to the authentication server 3. In S55, the authentication server 3 determines whether the device identifier received in S54 matches the device identifier associated with the line information received in S52 in the determination information. If they do not match, the authentication server 3 notifies the processing unit 11 of the authentication failure. This completes the sequence in Figure 6. In the example in Figure 6, they match, so the authentication server 3 sends challenge data to the SIM 10 in S56.

[0038] SIM10 generates signature data for the challenge data based on the stored private key and sends the signature data to the authentication server 3 in S57. In S58, the authentication server 3 verifies the signature data using the public key associated with the circuit information received in S52. If the verification is successful, in S59, the authentication server 3 sends the access token associated with the circuit information received in S52 to SIM10. In S60, SIM10 outputs the access token to the processing unit 11. The processing when the processing unit 11 uses the service provided by AS5 is the same as in the first embodiment.

[0039] The SIM10 has a processor and is configured to run simple applications such as applets. Therefore, it is possible to have the SIM10 perform processing that conforms to encrypted communication protocols such as HTTPS.

[0040] Furthermore, if WD1 is a device that is operated by a human, such as a smartphone, the trigger for the processing unit 11 to start the sequence in Figures 3 and 6 may be, for example, when the user of WD1 performs an operation to access AS5. In this case, the processing unit 11 starts the process in Figure 4 after obtaining an access token. The processing unit 11 may also start the sequence in Figures 3 and 6 as a trigger if it does not have a valid access token or if the access token has expired. In this case, the processing unit 11 starts the process in Figure 4 at a pre-programmed timing or at a timing when it becomes necessary to access AS5 due to a change in circumstances.

[0041] With the above configuration, access tokens can be issued only when the authenticator, SIM10, is implemented in a specific WD1. Furthermore, this embodiment can reduce the risk of leakage of network information.

[0042] <Example configuration of authentication server 3> Figure 7 is a schematic diagram of the authentication server 3. The authentication server 3 includes, for example, one or more processors and one or more memory devices. The one or more memory devices may include volatile memory devices and non-volatile memory devices. Each functional block shown in Figure 7 can be realized by one or more processors executing computer programs stored in one or more memory devices.

[0043] Although the authentication server 3 in Figure 7 is a single device, the authentication server 3 may be implemented by multiple devices that can communicate with each other. Furthermore, Figure 7 shows only the functional blocks necessary for understanding this disclosure, and the authentication server 3 may have functional blocks other than those shown in Figure 7.

[0044] The storage unit 30 stores determination information that indicates the relationship between the line information and the device identifier. When the processing unit 31 obtains a public key from WD1 through the registration process described in Figures 2 and 5, it stores the public key in the storage unit 30, associating it with the line information of WD1.

[0045] The acquisition unit 32 is configured to access the determination information stored in the storage unit 30. In response to receiving an authentication request containing first line information from the WD1 of the mobile communication network 21, it acquires the first device identifier associated with the first line information from the mobile communication network 21. The acquisition unit 32 may be configured to perform the process of acquiring the device identifier from the mobile communication network only if the determination information contains first line information.

[0046] The processing unit 31 determines that authentication of WD1 is unsuccessful if the first device identifier does not match the device identifier associated with the first line information in the determination information. The processing unit 31 may also determine that authentication of WD1 is unsuccessful if the determination information does not include the first line information. The processing unit 31 may also determine that authentication of WD1 is unsuccessful if it cannot obtain the public key associated with the first line information.

[0047] If the processing unit 31 determines that the first device identifier matches the device identifier associated with the first circuit information in the determination information, it sends challenge data to WD1 and receives signed data of the challenge data from WD1. The processing unit 31 verifies the signed data based on the public key associated with the first circuit information, and if the verification of the signed data is successful, it may determine that authentication of WD1 has been successful. If the processing unit 31 determines that authentication of WD1 has been successful, it may send the first access token associated with the first circuit information to WD1.

[0048] For example, the first access token is stored in the storage unit 30 in association with the first line information, and the processing unit 31 can transmit the first access token stored in the storage unit 30 to the WD1. Alternatively, the processing unit 31 can obtain the first access token from another device based on the first line information and transmit it to the WD1.

[0049] In Figure 7, the storage unit 30 is shown as a component of the authentication server 3, but the storage unit 30 can also be configured to be located on an external device to the authentication server 3. In this case, instead of the storage unit 30 in Figure 7, the authentication server 3 is provided with an access unit or acquisition unit that accesses the external device and retrieves the information stored on that device.

[0050] Furthermore, the Disclosure provides a program executable on one or more processors. The program, when executed on one or more processors of a device or apparatus, includes instructions that cause the device or apparatus to function, for example, as WD1 or authentication server 3. Furthermore, the Disclosure provides a non-temporary computer-readable storage medium containing the program. Furthermore, the Disclosure provides methods that WD1 or authentication server 3 execute for the processes illustrated in Figures 2 to 6. Furthermore, the Disclosure provides a program for causing a device having one or more processors to execute these methods, and a non-temporary computer-readable storage medium containing the program.

[0051] The invention is not limited to the embodiments described above, and various modifications and changes are possible within the scope of the gist of the invention.

[0052] With the above configuration, access tokens can be issued only when the authenticator, SIM, is implemented in a specific WD. Therefore, it becomes possible to contribute to Goal 9 of the United Nations-led Sustainable Development Goals (SDGs): "Build resilient infrastructure, promote sustainable industrialization and foster innovation." [Explanation of symbols]

[0053] 30: Storage unit, 31: Processing unit, 32: Acquisition unit

Claims

1. An access means that can access determination information showing the relationship between line information and device identifier, An acquisition means that, in response to receiving an authentication request including first circuit information from a wireless device of a mobile communication network, acquires a first device identifier associated with the first circuit information from the mobile communication network, Processing means for determining that authentication of the wireless device is unsuccessful if the first device identifier does not match the device identifier associated with the first line information in the determination information, An authentication server equipped with this feature.

2. The authentication server according to claim 1, wherein the processing means determines that the authentication of the wireless device is unsuccessful if the determination information does not include the first line information.

3. The authentication server according to claim 1, wherein the processing means, upon determining that the authentication of the wireless device has been successful, transmits a first access token associated with the first line information to the wireless device.

4. The authentication server according to claim 3, wherein the processing means transmits challenge data to the wireless device when the first device identifier matches the device identifier associated with the first line information in the determination information, and when it receives signature data of the challenge data from the wireless device as a response to the transmission of the challenge data, it verifies the signature data based on the public key associated with the first line information, and determines that the authentication of the wireless device is successful if the verification of the signature data is successful.

5. The aforementioned determination information also shows the relationship between the line information and the access token. The authentication server according to claim 3, wherein the processing means transmits the first access token indicated by the determination information to the wireless device.

6. The authentication server according to claim 3, wherein the processing means obtains the first access token from another device based on the first line information and transmits it to the wireless device.

7. The authentication server according to claim 1, wherein the line information is information stored in an integrated circuit implemented in the wireless device and which stores a profile for the wireless device to access the mobile communication network.

8. The authentication server according to claim 7, wherein the line information is an identifier of the integrated circuit, a subscriber identifier assigned to the profile by the operator of the mobile communication network, or a combination of the identifier of the integrated circuit and the subscriber identifier.

9. The identifier of the aforementioned integrated circuit is an integrated circuit card identifier (ICCID) or an embedded identification document (EID), The authentication server according to claim 8, wherein the subscriber identifier is an International Mobile Subscriber Identifier (IMSI).

10. A program that, when executed on one or more processors of a device having one or more processors, causes the device to function as an authentication server according to any one of claims 1 to 9.

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