Patent Publication Number: US-2022216987-A1

Title: Device and method for managing shared digital key

Description:
TECHNICAL FIELD 
     The present disclosure relates to a device and method for managing a shared digital key. 
     BACKGROUND ART 
     As personalized electronic devices, such as smartphones and tablet personal computers (PCs), become popular, technologies for performing security, authentication, and the like using a digitized virtual key (i.e. , digital key) are under development. As one of such digital key technologies, a technology of integrating a digital key into a mobile device, for example, a smartphone by using a wireless communication technology such near field communication (NFC) is being developed. 
     By inserting a digital key into a mobile device, a user of the mobile device may open and close a door by using the digital key, in replacement of a physical key. In addition, as the function of the digital key is further expanded, the user of the mobile device may use the digital key to access and control the mobile device. 
     The use of digital keys may bring great improvements in user convenience and industrial effectiveness, but security concerns are also raised. Due to the nature of digital keys that require connection with electronic devices, the electronic devices may be exposed to risks such as hacking. Therefore, it is necessary to manage digital keys in a high-security area. 
     DESCRIPTION OF EMBODIMENTS 
     Technical Problem 
     Various embodiments of the present disclosure provide a device and method for managing a shared digital key. 
     Solution to Problem 
     According to various embodiments of the present disclosure, an operating method of an electronic device for managing a digital key includes: receiving a response message to a request message for managing a shared digital key; verifying information included in the received response message; and managing the shared digital key based on the verified information. 
     According to various embodiments of the present disclosure, an operating method of a target device includes: verifying information included in a request message for managing a shared digital key; generating a response message to the request message based on the verified information; and transmitting the generated response message. 
     According to various embodiments of the present disclosure, an electronic device includes: a communicator configured to receive a response message to a request message for managing a shared digital key; and at least one processor configured to verify information included in the received response message and manage the shared digital key based on the verified information. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a diagram for describing an environment to which a digital key is applied, according to various embodiments of the present disclosure. 
         FIG. 2  is a diagram for describing a system for implementing a service by using a digital key, according to various embodiments of the present disclosure. 
         FIG. 3  is a sequence diagram for schematically describing a method of managing a shared digital key, according to various embodiments of the present disclosure. 
         FIG. 4  illustrates an example of information included in a request message and a response message, according to various embodiments of the present disclosure. 
         FIG. 5  is a flowchart of an operating process of an electronic device, according to various embodiments of the present disclosure. 
         FIG. 6  is a flowchart of an operating process of a target device, according to various embodiments of the present disclosure. 
         FIG. 7  is a sequence diagram for schematically describing a digital key management method initiated or triggered by an electronic device, according to various embodiments of the present disclosure. 
         FIG. 8  is a sequence diagram for schematically describing a digital key management method initiated or triggered by a target device, according to various embodiments of the present disclosure. 
         FIG. 9  is a sequence diagram for schematically describing a digital key management method initiated or triggered by a first backend server, according to various embodiments of the present disclosure. 
         FIG. 10  is a sequence diagram for schematically describing a digital key management method initiated or triggered by a second backend server, according to various embodiments of the present disclosure. 
         FIG. 11  is a diagram illustrating a configuration of an electronic device, according to various embodiments of the present disclosure. 
         FIG. 12  is a diagram illustrating a configuration of a target device, according to various embodiments of the present disclosure. 
         FIG. 13  is a diagram illustrating a configuration of a secure element, according to various embodiments of the present disclosure. 
     
    
    
     BEST MODE 
     According to various embodiments of the present disclosure, an operating method of an electronic device for managing a digital key includes: receiving a response message to a request message for managing a shared digital key; verifying information included in the received response message; and managing the shared digital key based on the verified information. 
     Mode of Disclosure 
     Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that the present disclosure may be easily carried out by those of ordinary skill in the art. However, the present disclosure may be embodied in many different forms and is not limited to the embodiments of the present disclosure described herein. Also, in order to clearly describe the present disclosure, parts having no relation to the description are omitted, and like reference numerals are assigned to like elements throughout the specification. 
     Some embodiments of the present disclosure may be represented by functional block configurations and various processing steps. All or part of these functional blocks may be implemented in various numbers of hardware and/or software configurations that perform specific functions. For example, the functional blocks of the present disclosure may be implemented by one or more microprocessors, or may be implemented by circuit configurations for certain functions. Also, for example, the functional blocks of the present disclosure may be implemented in various programming or scripting languages. The functional blocks may be implemented as an algorithm that is executed on one or more processors. Also, the present disclosure may employ the related art for electronic configuration, signal processing, and/or data processing. 
     In addition, connecting lines or connecting members between elements illustrated in the drawings only exemplify functional connections and/or physical or circuit connections. In an actual device, a connection between elements may be represented by various functional connections, physical connections, or circuit connections that are replaceable or added. 
     Hereinafter, the present disclosure will be described in detail with reference to the accompanying drawings. 
       FIG. 1  is a diagram for describing an environment to which a digital key is applied, according to various embodiments of the present disclosure. 
     Referring to  FIG. 1 , an owner device  100 , a user  1  of the owner device  100 , and electronic devices  11 ,  12 , . . . for performing access and control by using a digital key stored in the owner device  100  is disclosed. In various embodiments, the user  1  who uses the owner device  100  may be referred to as an owner. 
     The owner device  100  may include a personalized mobile device, but the present disclosure is not limited thereto. The owner device  100  may include various types of electronic devices. For example, the owner device  100  may include a smartphone, a tablet personal computer (PC), a PC, a camera, and a wearable device. The owner device  100  may perform a process of accessing the electronic devices  11 ,  12 , . . . and generating, deleting, and managing digital keys for controlling the electronic devices  11 ,  12 , . . . , and may perform authentication on the digital keys. 
     The electronic devices  11 ,  12 , . . . may interoperate with the owner device  100  to perform an operation for generating the digital keys, and may be controlled and accessed by using the digital keys. 
     As an example, the owner device  100  may store a digital key for interoperating with the electronic device  11  mounted on an automobile. The owner device  100  may control various operations of the automobile by using the stored digital key. For example, the owner device  100  may use the digital key to open and close a door of the automobile, start an engine, and control various devices mounted on the automobile. Furthermore, the owner device  100  may also control an operation related to autonomous driving, such as an automatic parking system. 
     As another example, the owner device  100  may store a digital key for interoperating with a doorlock  12 . The owner device  100  may open and close a door by using the stored digital key. 
     The electronic device that the owner device  100  may control by using the digital key is not limited to the example illustrated in  FIG. 1 , and the digital key technology may be applied to various electronic devices. Hereinafter, for convenience of description, a case in which the owner device  100  interoperates with the electronic device  11  mounted on the automobile will be described as an example. However, the following description may also be applied to a case in which the owner device  100  interoperates with various electronic devices other than the electronic device  11  mounted on the automobile. 
       FIG. 2  is a diagram for describing a system for implementing a service by using a digital key, according to various embodiments of the present disclosure. 
     Referring to  FIG. 2 , an owner device backend server  210 , a target device backend server  220 , a backend server  230  for an electronic device of another user, an owner device  100 , a first near field communication (NFC) reader  250 - 1 , an electronic device  11 , a second NFC reader  250 - 2 , an electronic device  240  of another user, and digital keys  260 - 1 ,  260 - 2 , and  260 - 3  of another user are illustrated. In various embodiments of the present disclosure, the electronic device  11  may be referred to as a target device  11 . 
     Although not illustrated in  FIG. 2 , a service provider server is a server that is operated by a service provider which provides a digital key service to a user. The service provider refers to a business operator that provides services related to, for example, automobile, hotels, houses, buildings, and the like, and may provide a digital key service to a user as an additional service based on a main service. For example, an automobile company sells automobiles, and a hotel, house, or building company provides services related to hotels, houses, or buildings. For example, the service provider server may be operated by an automobile company. For example, the service provider server may provide a digital key service for an access function such as door opening and closing, engine start, and control. 
     The service provider server may include a user information database that stores user account information such as user identifier (ID) and password, selling product, or service information. For example, when an automobile company sells an automobile, the service provider server may store information about user ID, password, identification number of the sold automobile, and use or non-use of a digital key service. 
     The owner device backend server (or backend server)  210  provides a technology and service capable of securely issuing a digital key to the owner device  100  and storing the digital key. The owner device backend server  210  may be, for example, a server that is operated by a manufacturer (original equipment manufacturer (OEM)) of the owner device  100 , a server that is operated by a telecommunications company that provides a mobile communication service, or a server that is operated by a service provider that provides a digital key service. 
     For example, when the user  1  purchases an automobile and stores a digital key of the automobile on the owner device  100 , the owner device  100  may perform an authentication procedure. For example, the owner device  100  may perform an authentication procedure to check whether the user  1  is a valid user, the automobile is a valid automobile, and the like. The owner device backend server  210  may support such an authentication procedure. 
     The target device backend server  220  may provide a digital key service related to the target device. For example, the target device backend server  220  may provide a digital key service for an access function such as door opening and closing, engine start, and control. In an embodiment, the target device backend server  220  may be a server that is operated by a service provider which provides a digital key service to a user. More specifically, the target device backend server  220  may be a server that is operated by a manufacturer of the target device  11 . The service provider may refer to a business operator that provides services related to, for example, automobile, hotels, houses, buildings, and the like, and may provide a digital key service to a user as an additional service based on a main service. For example, when an automobile company sells automobiles and a hotel, house, or building company provides services related to hotels, houses, or buildings, the target device backend server  220  may be operated by the automobile company or the hotel, house, or building company. 
     In an embodiment, the target device backend server  220  may include a user information database that stores user account information such as user ID and password, selling product, or service information. For example, when an automobile company sells an automobile, the target device backend server  220  may store information about user ID, password, identification number of the sold automobile, and use or non-use of a digital key service. 
     In an embodiment, the target device backend server  220  may transmit information for the digital key service to the owner device backend server  210  in order to provide the digital key service to the user. In addition, the target device backend server  220  may transmit information for the digital key service to the backend server  230  for the electronic device of another user in order to provide the digital key service to another user (e.g. , a friend). 
     The backend server  230  for the electronic device of another user may be a server that is operated by a manufacturer of the electronic device  240  of another user (e.g. , a friend) other than an owner. The manufacturer of the owner device  100  may be identical to or different from the manufacturer of the electronic device  240  of another user (e.g. , a friend). 
     The electronic device  11  is an entity corresponding to a product and a service that the service provider sells to the user. For example, the electronic device  11  may include a gate of an automobile, a hotel, a house, a building, or the like. More specifically, the electronic device  11  may include not only a vehicle door, a trunk gate, and an oil filling port in an automobile, but also an access gate for engine start and vehicle control. 
     In various embodiments of the present disclosure, the owner device  100 , the target device  11 , and the electronic device  240  of another user may share the digital key of another user. For example, the owner device may store a digital key  260 - 1  of another user, the target device may store a digital key  260 - 2  of another user, and another user may store his or her digital key  260 - 3 . In various embodiments, the owner device  100  may manage the target device  11  and the digital key through the first NFC reader  250 - 1 . The electronic device  240  of another user may manage the target device  11  and the digital key through the second NFC reader  250 - 2 . 
     A method of managing a digital key shared between devices when the digital key of another user is shared by the owner device  100 , the target device  11 , and the electronic device  240  of another user, according to various embodiments of the present disclosure, will be described. That is, a method of managing the digital key  260 - 2  of another user stored in the target device  11 , according to various embodiments of the present disclosure, will be described. In this case, the management of the shared digital key may refer to revocation or updating of the shared digital key. In various embodiments, the above-described management of the shared digital key may be requested by the user  1  (e.g. , the owner) or another user (e.g. , the friend). In various embodiments, the above-described management of the shared digital key may be initiated or triggered by the owner device  100 , the electronic device  240  of another user, the target device  11 , the owner device backend server  210 , the backend server  230  for the electronic device of another user, or the target device backend server  220 . In various embodiments of the present disclosure, initiating or triggering may mean that the management of the shared digital key is started. 
     In various embodiments of the present disclosure, the user  1  (e.g. , the owner) or another user (e.g. , the friend) may make a request to revoke the digital key  260 - 2  of another user stored in the target device  11 . In this case, the operation of revoking the digital key  260 - 2  of another user may be initiated or triggered by the owner device  100 , the electronic device  240  of another user, the target device  11 , the owner device backend server  210 , the backend server  230  for the electronic device of another user, or the target device backend server  220 . In various embodiments, the revoking of the shared digital key may refer to revocation of the permission to share the digital key shared with another user. 
     In various embodiments of the present disclosure, the user  1  (e.g. , the owner) may make a request to update the digital key  260 - 2  of another user stored in the target device  11 . In this case, the operation of updating the digital key  260 - 2  of another user may be initiated or triggered by the owner device  100 , the target device  11 , the owner device backend server  210 , or the target device backend server  220 . In various embodiments, the updating of the shared digital key may refer to changing information about an expiration date of the digital key shared with another user or the permission to use the digital key shared with another user. In an embodiment, the permission to use the shared digital key may refer to permission to open and close an automobile door, to open and close a trunk door, or to start an automobile. In an embodiment, an update request other than the permission to use the shared digital key may be requested by another user (e.g. , the friend). However, the present disclosure may be implemented in various different forms, and is not limited to the embodiments described herein. Hereinafter, a method of managing a pre-shared digital key will be described. 
       FIG. 3  is a sequence diagram for schematically describing a method of managing a shared digital key, according to various embodiments of the present disclosure. 
     Referring to  FIG. 3 , an electronic device  310  may refer to the owner device  100  or the electronic device  240  of another user. A target device  320  may refer to the electronic device  11 . For example, the electronic device  11  may refer to an automobile or an electronic device mounted on the automobile. In various embodiments, the electronic device  310  may be referred to as an initiator. 
     In operation  301 , the electronic device  310  may generate a request message. For example, the electronic device  310  may generate a message requesting management of a shared digital key. In various embodiments, the request message may include information about the shared digital key, request information, routing information, or a signature of a sender who has transmitted the request message. For example, the signature of the sender may refer to a signature of a user of the electronic device  310 . 
     In operation  303 , the electronic device  310  may transmit the request message. For example, the electronic device  310  may transmit the generated request message to the target device  320 . 
     In operation  305 , the target device  320  may verify the received request message.27388387118362 For example, the target device  320  may verify information about the shared digital key, request information, or a signature of a sender transmitting the request message, which is included in the received request message. 
     In operation  307 , the target device  320  may perform an operation according to the request. That is, the target device  320  may perform shared digital key management based on the information included in the request message. For example, when the request information of the request message includes information related to the revocation of the shared digital key, the target device  320  may revoke the shared digital key stored in the target device  320 . When the request information of the request message includes information related to the updating of the shared digital key, the target device  320  may update the shared digital key stored in the target device  320 . 
     In operation  309 , the target device  320  may generate a response message. In various embodiments, the response message may include information about the shared digital key, response information, routing information, or a signature of a sender transmitting the response message. For example, the signature of the sender may refer to a signature of a user of the target device  320 . 
     In operation  311 , the target device  320  may transmit the response message. For example, the target device  320  may transmit the generated response message to the electronic device  310 . 
     In operation  313 , the electronic device  310  may verify the response message. For example, the electronic device  310  may verify information about the shared digital key, response information, or a signature of a sender transmitting the response message, which is included in the response message. 
     In operation  315 , the electronic device  310  may perform an operation according to the response. For example, when the response information of the response message includes information related to the revocation of the shared digital key, the electronic device  310  may revoke the shared digital key stored in the electronic device  310 . When the response information of the response message includes information related to the updating of the shared digital key, the electronic device  310  may update the shared digital key stored in the electronic device  310 . 
     Through the above-described operations, the electronic device  310  and the target device  320  may manage the shared digital key of another user. The meaning of the information included in the request message and the response message will be described in detail with reference to  FIG. 4 . 
       FIG. 4  illustrates an example of the information included in the request message and the response message, according to various embodiments of the present disclosure. 
     Referring to  FIG. 4 , the request message  410  may include digital key information  412 , request information  414 , routing information  416 , and a sender signature  418 . The response message  420  may include digital key information  422 , response information  424 , routing information  426 , and a sender signature  428 . 
     In various embodiments, the digital key information included in the request message  410  may include information related to a shared digital key. For example, the digital key information may include a unique ID of the shared digital key. The unique identifier may distinguish the shared digital key from other digital keys. 
     In various embodiments, the request information  414  included in the request message  410  may refer to information requesting the management of the shared digital key. For example, the management of the shared digital key may refer to revocation or updating of the shared digital key. In an embodiment, the request information may include data (revocation request) for revoking the shared digital key. In another embodiment, the request information may include data (update request) for updating the shared digital key. Although the revocation or updating of the digital key is described as an example of the method of managing the digital key, the present disclosure is not limited thereto. 
     In various embodiments, the routing information  416  included in the request message  410  may include information related to a transmission path of the request message  410 . For example, the routing information  416  may include an address for a destination to which the request message  410  is to be transmitted. In an embodiment, the address for the destination to which the request message  410  is to be transmitted may refer to a packet address to which a data packet is to be transmitted. 
     In various embodiments, the sender signature  418  included in the request message  410  may include information related to the signature of the sender who has transmitted the request message. For example, when the request message  410  is transmitted from the electronic device  310 , the sender signature  418  may refer to a signature of a user of the electronic device  310 . In various embodiments, the device receiving the request message  410  may verify, through the sender signature  418  included in the request message  410 , whether the request message  410  has been transmitted by a correct sender. 
     In various embodiments, the digital key information included in the response message  420  may include information related to a shared digital key. For example, the digital key information may include a unique ID of the shared digital key. The unique identifier may distinguish the shared digital key from other digital keys. 
     In various embodiments, the response information  424  included in the response message  420  may refer to information requesting the management of the shared digital key. For example, a response to the management of the shared digital key may refer to a result of revoking or updating the shared digital key. That is, when the request information  414  included in the request message  410  indicates the revocation of the shared digital key, the target device  320  may revoke the shared digital key and include a result thereof in the response information  424 . That is, when the request information  414  included in the request message  410  indicates the updating of the shared digital key, the target device  320  may update the shared digital key and include a result thereof in the response information  424 . 
     In an embodiment, the response information  424  may include data (revocation_attestation) indicating a result of revoking the shared digital key. In another embodiment, the response information  424  may include data (update_confirmation) indicating a result of updating the shared digital key. Although the revocation or updating of the digital key is described as the method of managing the digital key, the present disclosure is not limited thereto. 
     In various embodiments, the routing information  426  included in the response message  420  may include information related to a transmission path of the response message  420 . For example, the routing information  426  may include an address for a destination to which the response message  420  is to be transmitted. In an embodiment, the address for the destination to which the response message  420  is to be transmitted may refer to a packet address to which a data packet is to be transmitted. 
     In various embodiments, the sender signature  428  included in the response message  420  may include information related to the signature of the sender who has transmitted the response message. For example, when the response message  420  is transmitted from the target device  320 , the sender signature  428  may refer to a signature of a user of the target device  320 . In various embodiments, the device receiving the response message  420  may verify, through the sender signature  428  included in the response message  420 , whether the response message  420  has been transmitted by a correct sender. Although it has been described that the request message  410  may include the digital key information  412 , the request information  414 , the routing information  416 , and the sender signature  418 , and the response message  420  may include the digital key information  422 , the response information  424 , the routing information  426 , and the sender signature  428 , the present disclosure is not limited thereto. 
       FIG. 5  is a flowchart of the operating process of the electronic device, according to various embodiments of the present disclosure. Hereinafter, the electronic device  310  may refer to the owner device  100  or the electronic device  240  of another user. In addition, the first backend server may refer to the backend server of the electronic device  310 , and the second backend server may refer to the backend server of the target device  320 . The backend server of the electronic device  310  may refer to the backend server  210  of the owner device or the backend server  230  for the electronic device of another user. 
     Referring to  FIG. 5 , in operation  501 , the electronic device  310  may receive a response message to a request message for managing a shared digital key. Although not illustrated in  FIG. 5 , in an embodiment, when the management of the shared digital key is initiated or triggered by the electronic device  310 , the electronic device  310  may generate the request message for managing the shared digital key and transmit the generated request message to the target device  320 . In another embodiment, when the management of the shared digital key is initiated or triggered by the target device  320 , the operation, performed by the electronic device  310 , of generating and transmitting the request message may be omitted. In another embodiment, when the management of the shared digital key is initiated or triggered by the first backend server, the first backend server may generate the request message. In another embodiment, when the management of the shared digital key is initiated or triggered by the second backend server, the second backend server may generate the request message. After that, the electronic device  310  may receive a response message to the request message for managing the shared digital key. 
     In operation  503 , the electronic device  310  may verify information included in the received response message. For example, the received response message may include at least one of digital key information, response information, routing information, or a sender signature. In various embodiments, the response information may refer to a response to the management of the shared digital key. For example, the response to the management of the shared digital key may refer to a result of revoking or updating the shared digital key. Also, the electronic device  310  may verify, through the sender signature, whether the response message has been transmitted by a correct sender. 
     In operation  505 , the electronic device  310  may manage the shared digital key based on the verified information. For example, when it is verified that the response information of the response message includes information related to the revocation of the shared digital key, the electronic device  310  may revoke the shared digital key stored in the electronic device  310 . When it is verified that the response information of the response message includes information related to the updating of the shared digital key, the electronic device  310  may update the shared digital key stored in the electronic device  310 . As the method of managing the shared digital key, the revocation or updating of the shared digital key is described in operation  505 , but the present disclosure is not limited thereto. 
       FIG. 6  is a flowchart of the operating process of the target device, according to various embodiments of the present disclosure. Hereinafter, the electronic device  310  may refer to the owner device  100  or the electronic device  240  of another user. In addition, the first backend server may refer to the backend server of the electronic device  310 , and the second backend server may refer to the backend server of the target device  320 . The backend server of the electronic device  310  may refer to the backend server  210  of the owner device or the backend server  230  for the electronic device of another user. 
     Although not illustrated in  FIG. 6 , in an embodiment, when the management of the shared digital key is initiated or triggered by the electronic device  310 , the target device  320  may receive the above-described request message from the electronic device  310 . In another embodiment, when the management of the shared digital key is initiated or triggered by the target device  320 , operation  601  may be replaced with an operation of managing the shared digital key. In another embodiment, when the management of the shared digital key is initiated or triggered by the first backend server, the target device  320  may receive, from the second backend server, a request message changed from the request message transmitted from the first backend server. In another embodiment, when the management of the shared digital key is initiated or triggered by the second backend server, the target device  320  may receive the request message generated by the second backend server. 
     Referring to  FIG. 6 , in operation  601 , the target device  320  may verify information included in the request message for managing the shared digital key. For example, the request message may include at least one of digital key information, request information, routing information, or a sender signature. In various embodiments, the request information may refer to information requesting the management of the shared digital key. For example, the management of the shared digital key may refer to revocation or updating of the shared digital key. Also, the target device  320  may verify, through the sender signature, whether the request message has been transmitted by a correct sender. 
     In operation  603 , the target device  320  may generate a response message to the request message based on the verified information. For example, the target device  320  may generate a response message including information about the shared digital key, response information, routing information, or a signature of a sender transmitting the response message. In various embodiments, the response information may refer to a response to the management of the shared digital key. For example, the response to the management of the shared digital key may refer to a result of revoking or updating the shared digital key. In various embodiments, the signature of the sender who has transmitted the response message may refer to the signature of the user of the target device  320 . 
     In operation  605 , the target device  320  may transmit the generated response message. In an embodiment, when a communication method using NFC is used, the generated response message may be directly transmitted to the electronic device  310 . In another embodiment, when a communication method using a hypertext transfer protocol (HTTP) is used, the generated response message may be transmitted to the first backend server or the electronic device  310  through the second backend server. Hereinafter,  FIGS. 7 to 10  illustrate embodiments of digital key management operations according to a device that initiates or triggers management of a shared digital key. 
       FIG. 7  is a sequence diagram for schematically describing a digital key management method initiated or triggered by an electronic device, according to various embodiments of the present disclosure. 
     Referring to  FIG. 7 , an electronic device  310  may refer to the owner device  100  or the electronic device  240  of another user. A target device  320  may refer to the electronic device  11 . For example, the electronic device  11  may refer to an automobile or an electronic device mounted on the automobile. In addition, a first backend server  710  may refer to a backend server of the electronic device  310 , and a second backend server  720  may refer to a backend server of the target device  320 . The backend server of the electronic device  310  may refer to the backend server  210  of the owner device or the backend server  230  for the electronic device of another user. 
     In operation  701 , the electronic device  310  may generate a request message. That is, the electronic device  310  may generate a request message for managing a shared digital key of another user (e.g. , a friend). In various embodiments, the request message may include information about the shared digital key, request information, routing information, or a signature of a sender transmitting the request message. In an embodiment, the generated request message may be transmitted through an NFC connection between the electronic device  310  and the target device  320 . Hereinafter, a communication scenario through an NFC connection may be referred to as an “option 1” scenario. In another embodiment, the generated request message may be transmitted through an HTTP communication method via the first backend server  710  or the second backend server  720 . In this case, the HTTP communication method may refer to a communication method through an Internet connection. Hereinafter, a communication scenario through an HTTP connection may be referred to as an “option 2” scenario. In various embodiments, in the case of the option 1 scenario, operations  703  to  715  may be performed after operation  701 . 
     In operation  703 , the electronic device  310  may transmit the request message. For example, the electronic device  310  may transmit the generated request message to the target device  320 . At this time, the request message may be transmitted through an NFC connection between the electronic device  310  and the target device  320 . 
     In operation  705 , the target device  320  may verify the received request message. For example, the target device  320  may verify information about the shared digital key, request information, or a signature of a sender transmitting the request message, which is included in the received request message. 
     In operation  707 , the target device  320  may perform an operation according to the request. That is, the target device  320  may perform shared digital key management based on the information included in the request message. For example, when the request information of the request message includes information related to the revocation of the shared digital key, the target device  320  may revoke the shared digital key stored in the target device  320 . When the request information of the request message includes information related to the updating of the shared digital key, the target device  320  may update the shared digital key stored in the target device  320 . 
     In operation  709 , the target device  320  may generate a response message. In various embodiments, the response message may include information about the shared digital key, response information, routing information, or a signature of a sender transmitting the response message. For example, the signature of the sender may refer to a signature of a user of the target device  320 . In various embodiments, the response information may include information about a result of revoking or updating the shared digital key. 
     In operation  711 , the target device  320  may transmit the response message. For example, the target device  320  may transmit the generated response message to the electronic device  310 . At this time, the response message may be transmitted through an NFC connection between the electronic device  310  and the target device  320 . 
     In operation  713 , the electronic device  310  may verify the response message. For example, the electronic device  310  may verify information about the shared digital key, response information, or a signature of a sender transmitting the response message, which is included in the response message. 
     In operation  715 , the electronic device  310  may perform an operation according to the response. That is, the electronic device  310  may perform shared digital key management based on the information included in the verified response message. For example, when the response information of the response message includes information related to the revocation of the shared digital key, the electronic device  310  may revoke the shared digital key stored in the electronic device  310 . When the response information of the response message includes information related to the updating of the shared digital key, the electronic device  310  may update the shared digital key stored in the electronic device  310 . In various embodiments, the information related to the management of the shared digital key of the electronic device  310  may be transmitted to the first backend server  710  or the second backend server  720 . For example, the electronic device  310  may revoke or update the shared digital key and transmit, to the second backend server  720 , information related to a result of the revoking or the updating. After that, the first backend server  710  may transmit, to the second backend server  720 , information related to a result of the revoking or the updating. In various embodiments, in the case of the option 2 scenario, operations  717  to  737  may be performed after operation  701 . In this case, operations  723  to  727  may be performed in the same manner as operations  705  to  709 . In addition, operations  735  and  737  may be performed in the same manner as operations  713  and  715 . 
     In operation  717 , the electronic device  310  may transmit a request message. That is, the electronic device  310  may transmit the generated request message to the first backend server  710 . In this case, a mutual authentication procedure between the electronic device  310  and the first backend server  710  may be performed. 
     In operation  719 , the first backend server  710  may transmit the request message to the second backend server  720 . For example, the first backend server  710  may identify the second backend server  720  by using routing information included in the request message, and may transmit the request message to the second backend server  720 . In this case, a mutual authentication procedure between the first backend server  710  and the second backend server  720  may be performed. 
     In operation  721 , the second backend server  720  may transmit a request message to the target device  320 . In this case, a mutual authentication procedure between the second backend server  720  and the target device  320  may be performed. 
     In operation  723 , the target device  320  may verify the request message. For example, the target device  320  may verify information about the shared digital key, request information, or a signature of a sender transmitting the request message, which is included in the received request message. 
     In operation  725 , the target device  320  may perform an operation according to the request. That is, the target device  320  may perform shared digital key management based on the information included in the request message. For example, when the request information of the request message includes information related to the revocation of the shared digital key, the target device  320  may revoke the shared digital key stored in the target device  320 . When the request information of the request message includes information related to the updating of the shared digital key, the target device  320  may update the shared digital key stored in the target device  320 . 
     In operation  727 , the target device  320  may generate a response message. In various embodiments, the response message may include information about the shared digital key, response information, routing information, or a signature of a sender transmitting the response message. For example, the signature of the sender may refer to a signature of a user of the target device  320 . In various embodiments, the response information may include information about a result of revoking or updating the shared digital key. 
     In operation  729 , the target device  320  may transmit a response message to the second backend server  720 . In this case, a mutual authentication procedure between the target device  320  and the second backend server  720  may be performed. 
     In operation  731 , the second backend server  720  may transmit the response message. For example, the second backend server  720  may identify the first backend server  710  by using routing information included in the response message, and may transmit the response message to the first backend server  710 . In this case, a mutual authentication procedure between the first backend server  710  and the second backend server  720  may be performed. 
     In operation  733 , the first backend server  710  may transmit the response message. That is, the first backend server  710  may transmit the received response message to the electronic device  310 . In this case, a mutual authentication procedure between the electronic device  310  and the first backend server  710  may be performed. 
     In operation  735 , the electronic device  310  may verify the response message. For example, the electronic device  310  may verify information about the shared digital key, response information, or a signature of a sender transmitting the response message, which is included in the response message. 
     In operation  737 , the electronic device  310  may perform an operation according to the response. That is, the electronic device  310  may perform shared digital key management based on the information included in the verified response message. For example, when the response information of the response message includes information related to the revocation of the shared digital key, the electronic device  310  may revoke the shared digital key stored in the electronic device  310 . When the response information of the response message includes information related to the updating of the shared digital key, the electronic device  310  may update the shared digital key stored in the electronic device  310 . 
     When the digital key management procedure as described with reference to  FIG. 7  is performed in the option 1 scenario and the option 2 scenario, the following operations may be performed. 
     In an embodiment, when the management (e.g. , revocation or updating) of the shared digital key of another user is initiated or triggered by the owner device  100 , a notification about the management of the shared digital key may be transmitted to the electronic device  240  of another user or the backend server  230  for the electronic device of another user. 
     In another embodiment, when the management (e.g. , revocation) of the shared digital key of another user is initiated or triggered by the electronic device  240  of another user, a notification about the management of the shared digital key may be transmitted to the owner device  100  or the backend server  210  of the owner device. Through the procedures as described above, the digital key management operation initiated or triggered by the electronic device  310  may be performed. 
       FIG. 8  is a sequence diagram for schematically describing a digital key management method initiated or triggered by a target device, according to various embodiments of the present disclosure. 
     Referring to  FIG. 8 , an electronic device  310  may refer to the owner device  100  or the electronic device  240  of another user. A target device  320  may refer to the electronic device  11 . For example, the electronic device  11  may refer to an automobile or an electronic device mounted on the automobile. In addition, a first backend server  810  may refer to a backend server of the electronic device  310 , and a second backend server  820  may refer to a backend server of the target device  320 . The backend server of the electronic device  310  may refer to the backend server  210  of the owner device or the backend server  230  for the electronic device of another user. 
     In operation  801 , the target device  320  may perform digital key management. Although not illustrated in  FIG. 8 , before the target device  320  performs digital key management, a digital key management operation may be initiated or triggered by a request of a requester requesting digital key management. For example, the requester may refer to the user  1  of the owner device  100  or another user (e.g. , a friend) other than the owner. In an embodiment, the requester may request shared digital key management through a physical button of the target device  320 , a button on a user interface, or input of a password. When the target device  320  is started up, an additional authentication procedure for a shared digital key management request may not be required. In various embodiments, the requester&#39;s request for the shared digital key management to the target device  320  may be implemented in the form of a request message for managing the shared digital key. As described above, after the shared digital key management is requested, the target device  320  may perform a digital key management operation. For example, when the requester&#39;s request is to revoke the shared digital key, the target device  320  may revoke the shared digital key stored in the target device  320 . When the requester&#39;s request is to update the shared digital key, the target device  320  may update the shared digital key stored in the target device  320 . 
     In operation  803 , the target device  320  may generate a response message. For example, the target device  320  may perform a shared digital key management operation and generate a result thereof in the form of a response message. In various embodiments, the response message may include information about the shared digital key, response information, routing information, or a signature of a sender transmitting the response message. For example, the signature of the sender may refer to a signature of a user of the target device  320 . In various embodiments, the response information may include information about a result of revoking or updating the shared digital key. In an embodiment, the generated response message may be transmitted through an NFC connection between the electronic device  310  and the target device  320 . Hereinafter, a communication scenario through an NFC connection may be referred to as an “option 1” scenario. In another embodiment, the generated response message may be transmitted through an HTTP communication method via the first backend server  810  or the second backend server  820 . In this case, the HTTP communication method may refer to a communication method through an Internet connection. Hereinafter, a communication scenario through an HTTP connection may be referred to as an “option 2” scenario. In an embodiment, when the requester is the owner, the response message may be transmitted through an NFC connection between the electronic device  310  and the target device  320 , or may be transmitted through an HTTP connection via the first backend server  810  or the second backend server  820 . In another embodiment, when the requester is another user other than the owner, the response message may be transmitted through an HTTP connection via the first backend server  810  or the second backend server  820 . In various embodiments, in the case of the option 1 scenario, operations  805  to  809  may be performed after operation  803 . 
     In operation  805 , the target device  320  may transmit the response message. For example, the target device  320  may transmit the generated response message to the electronic device  310 . At this time, the response message may be transmitted through an NFC connection between the electronic device  310  and the target device  320 . 
     In operation  807 , the electronic device  310  may verify the response message. For example, the electronic device  310  may verify information about the shared digital key, response information, or a signature of a sender transmitting the response message, which is included in the response message. 
     In operation  809 , the electronic device  310  may perform an operation according to the response. That is, the electronic device  310  may perform shared digital key management based on the information included in the verified response message. For example, when the response information of the response message includes information related to the revocation of the shared digital key, the electronic device  310  may revoke the shared digital key stored in the electronic device  310 . When the response information of the response message includes information related to the updating of the shared digital key, the electronic device  310  may update the shared digital key stored in the electronic device  310 . In various embodiments, the information related to the management of the shared digital key of the electronic device  310  may be transmitted to the first backend server  810  or the second backend server  820 . For example, the electronic device  310  may revoke or update the shared digital key and transmit, to the first backend server  810 , information related to a result of the revoking or the updating. After that, the first backend server  810  may transmit, to the second backend server  820 , information related to a result of the revoking or updating. In various embodiments, in the case of the option 2 scenario, operations  811  to  819  may be performed after operation  803 . At this time, operations  817  and  819  may be performed in the same manner as operations  807  and  809 . 
     In operation  811 , the target device  320  may transmit the response message. For example, the target device  320  may transmit the generated response message to the second backend server  820 . In this case, a mutual authentication procedure between the target device  320  and the second backend server  820  may be performed. 
     In operation  813 , the second backend server  820  may transmit the response message. For example, the second backend server  820  may identify the first backend server  810  by using routing information included in the response message, and may transmit the response message to the first backend server  810 . In this case, a mutual authentication procedure between the first backend server  810  and the second backend server  820  may be performed. 
     In operation  815 , the first backend server  810  may transmit the response message. That is, the first backend server  810  may transmit the received response message to the electronic device  310 . In this case, a mutual authentication procedure between the electronic device  310  and the first backend server  810  may be performed. 
     In operation  817 , the electronic device  310  may verify the response message. For example, the electronic device  310  may verify information about the shared digital key, response information, or a signature of a sender transmitting the response message, which is included in the response message. 
     In operation  819 , the electronic device  310  may perform an operation according to the response. That is, the electronic device  310  may perform shared digital key management based on the information included in the verified response message. For example, when the response information of the response message includes information related to the revocation of the shared digital key, the electronic device  310  may revoke the shared digital key stored in the electronic device  310 . When the response information of the response message includes information related to the updating of the shared digital key, the electronic device  310  may update the shared digital key stored in the electronic device  310 . 
     When the digital key management procedure as described with reference to  FIG. 8  is performed in the option 1 scenario and the option 2 scenario, the following operations may be performed. 
     In an embodiment, when the management (e.g. , revocation or updating) of the shared digital key of another user is requested by the owner, a notification about the management of the shared digital key may be transmitted to the electronic device  240  of another user or the backend server  230  for the electronic device of another user. 
     In another embodiment, when the management (e.g. , revocation) of the shared digital key of another user is requested by another user, a notification about the management of the shared digital key may be transmitted to the owner device  100  or the backend server  210  of the owner device. Through the procedures as described above, the digital key management operation initiated or triggered by the target device  320  may be performed. 
       FIG. 9  is a sequence diagram for schematically describing a digital key management method initiated or triggered by a first backend server, according to various embodiments of the present disclosure. 
     Referring to  FIG. 9 , an electronic device  310  may refer to the owner device  100  or the electronic device  240  of another user. A target device  320  may refer to the electronic device  11 . For example, the electronic device  11  may refer to an automobile or an electronic device mounted on the automobile. In addition, a first backend server  910  may refer to a backend server of the electronic device  310 , and a second backend server  920  may refer to a backend server of the target device  320 . The backend server of the electronic device  310  may refer to the backend server  210  of the owner device or the backend server  230  for the electronic device of another user. 
     In operation  901 , the first backend server  910  may generate the request message. In various embodiments, the requester may request the shared digital key management to the first backend server  910 . In an embodiment, the request may refer to a request through a call of the requester or an application on the electronic device of the requester. The above-described request message may include information about the shared digital key, request information, routing information, or a signature of a sender transmitting the request message. Because the first backend server  910  transmits the request message, the request message may include the signature of the first backend server  910 . 
     In operation  903 , the first backend server  910  may transmit the request message. In various embodiments, the first backend server  910  may identify the second backend server  920  by using routing information included in the request message. The first backend server  910  may transmit the request message to the identified second backend server  920 . In this case, a mutual authentication procedure between the first backend server  910  and the second backend server  920  may be performed. 
     In operation  905 , the second backend server  920  may verify the request message. For example, the second backend server  920  may verify information about the shared digital key, request information, routing information, or a signature of a sender transmitting the request message, which is included in the request message. 
     In operation  907 , the second backend server  920  may generate the request message. That is, the second backend server  920  may generate a new request message by using information included in the request message received from the first backend server  910 . In an embodiment, when the shared digital key management operation is initiated or triggered by the first backend server  910 , the second backend server  920  may replace the signature of the first backend server  910  included in the received request message with its own signature. In another embodiment, the second backend server  920  may add its own signature in addition to the signature of the first backend server  910  included in the received request message. In another embodiment, the second backend server  920  may transmit the received request message to the target device  320  without generating a new request message. That is, the second backend server  920  may reuse the request message received from the first backend server  910  without generating a new request message based on the request message received from the first backend server  910 . As described above, when the second backend server  920  does not generate a new request message, operation  907  may be omitted. 
     In operation  909 , the second backend server  920  may transmit the request message. That is, the second backend server  920  may transmit, to the target device  320 , the request message including its own signature. In this case, a mutual authentication procedure between the target device  320  and the second backend server  920  may be performed. In another embodiment, when the second backend server  920  does not generate a new request message and transmits, to the target device  320 , the request message received from the first backend server  910 , the second backend server  920  may transmit, to the target device  320 , a message including its own signature or the signature of the first backend server  910 . 
     In operation  911 , the target device  320  may verify the received request message. For example, the target device  320  may verify information about the shared digital key, request information, or a signature of a sender transmitting the request message, which is included in the received request message. For example, the target device  320  may verify a request for the revocation or the updating of the shared digital key through the request information included in the request message. Also, the target device  320  may verify that the sender signature included in the request message is the signature of the second backend server  920 . In another embodiment, when the second backend server  920  does not generate a new request message and transmits, to the target device  320 , the request message received from the first backend server  910 , the target device  320  may verify that the sender signature included in the request message is the signature of the first backend server  910  or the second backend server  920 . 
     In operation  913 , the target device  320  may perform an operation according to the request. That is, the target device  320  may perform shared digital key management based on the information included in the request message. For example, when the request information of the request message includes information related to the revocation of the shared digital key, the target device  320  may revoke the shared digital key stored in the target device  320 . When the request information of the request message includes information related to the updating of the shared digital key, the target device  320  may update the shared digital key stored in the target device  320 . 
     In operation  915 , the target device  320  may generate a response message. In various embodiments, the response message may include information about the shared digital key, response information, routing information, or a signature of a sender transmitting the response message. For example, the signature of the sender may refer to a signature of a user of the target device  320 . In various embodiments, the response information may include information about a result of revoking or updating the shared digital key. 
     In operation  917 , the target device  320  may transmit the response message. For example, the target device  320  may transmit the generated response message to the second backend server  920 . In this case, a mutual authentication procedure between the target device  320  and the second backend server  920  may be performed. 
     In operation  919 , the second backend server  920  may verify the response message. For example, the second backend server  920  may verify routing information included in the response message. The second backend server  920  may identify, as the first backend server  910 , a target to which the response message is to be transmitted, based on the verified routing information. 
     In operation  921 , the second backend server  920  may transmit the response message. For example, the second backend server  920  may transmit the verified response message to the first backend server  910 . In this case, a mutual authentication procedure between the first backend server  910  and the second backend server  920  may be performed. 
     In various embodiments, a response message to the request message requesting the shared digital key management may be transmitted to the electronic device of the digital key management requester. In an embodiment, when the requester is the owner, the response message may be transmitted through an NFC connection between the electronic device  310  and the target device  320 , or may be transmitted through an HTTP connection via the first backend server  910  or the second backend server  920 . In another embodiment, when the requester is another user other than the owner, the response message may be transmitted through an HTTP connection via the first backend server  910  or the second backend server  920 . In an embodiment, the response message generated by the target device  320  in operation  915  may be transmitted through an NFC connection between the electronic device  310  and the target device  320 . Hereinafter, a communication scenario through an NFC connection may be referred to as an “option 1” scenario. In another embodiment, the response message generated by the target device  320  may be transmitted through the HTTP communication method via the first backend server  910  or the second backend server  920 . In this case, the HTTP communication method may refer to a communication method through an Internet connection. Hereinafter, a communication scenario through an HTTP connection may be referred to as an “option 2” scenario. In various embodiments, in the case of the option 1 scenario, operations  923  to  927  may be performed after operation  921 . 
     In operation  923 , the target device  320  may transmit the response message. For example, the target device  320  may transmit the generated response message to the electronic device  310 . At this time, the response message may be transmitted through an NFC connection between the electronic device  310  and the target device  320 . 
     In operation  925 , the electronic device  310  may verify the response message. For example, the electronic device  310  may verify information about the shared digital key, response information, or a signature of a sender transmitting the response message, which is included in the response message. 
     In operation  927 , the electronic device  310  may perform an operation according to the response. That is, the electronic device  310  may perform shared digital key management based on the information included in the verified response message. For example, when the response information of the response message includes information related to the revocation of the shared digital key, the electronic device  310  may revoke the shared digital key stored in the electronic device  310 . When the response information of the response message includes information related to the updating of the shared digital key, the electronic device  310  may update the shared digital key stored in the electronic device  310 . In various embodiments, in the case of the option 2 scenario, operations  929  to  933  may be performed after operation  921 . At this time, operations  931  and  933  may be performed in the same manner as operations  925  and  927 . 
     In operation  929 , the first backend server  910  may transmit the response message. For example, the first backend server  910  may transmit, to the electronic device  310 , the response message received from the second backend server  920  in operation  921 . In this case, a mutual authentication procedure between the first backend server  910  and the electronic device  310  may be performed. 
     In operation  931 , the electronic device  310  may verify the response message. For example, the electronic device  310  may verify information about the shared digital key, response information, or a signature of a sender transmitting the response message, which is included in the response message. 
     In operation  933 , the electronic device  310  may perform an operation according to the response. That is, the electronic device  310  may perform shared digital key management based on the information included in the verified response message. For example, when the response information of the response message includes information related to the revocation of the shared digital key, the electronic device  310  may revoke the shared digital key stored in the electronic device  310 . When the response information of the response message includes information related to the updating of the shared digital key, the electronic device  310  may update the shared digital key stored in the electronic device  310 . 
     When the digital key management procedure as described with reference to  FIG. 9  is performed in the option 1 scenario and the option 2 scenario, the following operations may be performed. 
     In an embodiment, when the management (e.g. , revocation or updating) of the shared digital key of another user is requested by the owner, a notification about the management of the shared digital key may be transmitted to the electronic device  240  of another user or the backend server  230  for the electronic device of another user. 
     In another embodiment, when the management (e.g. , revocation) of the shared digital key of another user is requested by another user, a notification about the management of the shared digital key may be transmitted to the owner device  100  or the backend server  210  of the owner device. Through the procedures as described above, the digital key management operation initiated or triggered by the first backend server may be performed. 
       FIG. 10  is a sequence diagram for schematically describing a digital key management method initiated or triggered by a second backend server, according to various embodiments of the present disclosure. 
     Referring to  FIG. 10 , an electronic device  310  may refer to the owner device  100  or the electronic device  240  of another user. A target device  320  may refer to the electronic device  11 . For example, the electronic device  11  may refer to an automobile or an electronic device mounted on the automobile. In addition, a first backend server  1010  may refer to a backend server of the electronic device  310 , and a second backend server  1020  may refer to a backend server of the target device  320 . The backend server of the electronic device  310  may refer to the backend server  210  of the owner device or the backend server  230  for the electronic device of another user. 
     In operation  1001 , the second backend server  1020  may generate a request message. In various embodiments, a requester may request a shared digital key management to the second backend server  1020 . In an embodiment, the request may refer to a request through a call of the requester or an application on the electronic device of the requester. The above-described request message may include information about the shared digital key, request information, routing information, or a signature of a sender transmitting the request message. Because the second backend server  1020  transmits the request message, the request message may include the signature of the second backend server  1020 . 
     In operation  1003 , the second backend server  1020  may transmit the request message. That is, the second backend server  1020  may transmit, to the target device  320 , the request message including its own signature. In this case, a mutual authentication procedure between the target device  320  and the second backend server  1020  may be performed. 
     In operation  1005 , the target device  320  may verify the received request message. For example, the target device  320  may verify information about the shared digital key, request information, or a signature of a sender transmitting the request message, which is included in the received request message. For example, the target device  320  may verify a request for the revocation or the updating of the shared digital key through the request information included in the request message. Also, the target device  320  may verify that the sender signature included in the request message is the signature of the second backend server  920 . 
     In operation  1007 , the target device  320  may perform an operation according to the request. That is, the target device  320  may perform shared digital key management based on the information included in the request message. For example, when the request information of the request message includes information related to the revocation of the shared digital key, the target device  320  may revoke the shared digital key stored in the target device  320 . When the request information of the request message includes information related to the updating of the shared digital key, the target device  320  may update the shared digital key stored in the target device  320 . 
     In operation  1009 , the target device  320  may generate a response message. In various embodiments, the response message may include information about the shared digital key, response information, routing information, or a signature of a sender transmitting the response message. For example, the signature of the sender may refer to a signature of a user of the target device  320 . In various embodiments, the response information may include information about a result of revoking or updating the shared digital key. 
     In operation  1011 , the target device  320  may transmit a response message. For example, the target device  320  may transmit the generated response message to the second backend server  1020 . In this case, a mutual authentication procedure between the target device  320  and the second backend server  1020  may be performed. 
     In operation  1013 , the second backend server  1020  may verify the response message. For example, the second backend server  1020  may verify routing information included in the response message. In an embodiment, the second backend server  1020  may identify, as the first backend server  1010 , a target to which the response message is to be transmitted, based on the verified routing information. 
     In various embodiments, a response message to the request message requesting the shared digital key management may be transmitted to the electronic device of the digital key management requester. In an embodiment, when the requester is the owner, the response message may be transmitted through an NFC connection between the electronic device  310  and the target device  320 , or may be transmitted through an HTTP connection via the first backend server  910  or the second backend server  920 . In another embodiment, when the requester is another user other than the owner, the response message may be transmitted through an HTTP connection via the first backend server  910  or the second backend server  920 . In an embodiment, the response message generated by the target device  320  in operation  1009  may be transmitted through an NFC connection between the electronic device  310  and the target device  320 . Hereinafter, a communication scenario through an NFC connection may be referred to as an “option 1” scenario. In another embodiment, the response message generated by the target device  320  may be transmitted through the HTTP communication method via the first backend server  910  or the second backend server  920 . In this case, the HTTP communication method may refer to a communication method through an Internet connection. Hereinafter, a communication scenario through an HTTP connection may be referred to as an “option 2” scenario. In various embodiments, in the case of the option 1 scenario, operations  1015  to  1019  may be performed after operation  1013 . 
     In operation  1015 , the target device  320  may transmit a response message. For example, the target device  320  may transmit the generated response message to the electronic device  310 . At this time, the response message may be transmitted through an NFC connection between the electronic device  310  and the target device  320 . 
     In operation  1017 , the electronic device  310  may verify the response message. For example, the electronic device  310  may verify information about the shared digital key, response information, or a signature of a sender transmitting the response message, which is included in the response message. 
     In operation  1019 , the electronic device  310  may perform an operation according to the response. That is, the electronic device  310  may perform shared digital key management based on the information included in the verified response message. For example, when the response information of the response message includes information related to the revocation of the shared digital key, the electronic device  310  may revoke the shared digital key stored in the electronic device  310 . When the response information of the response message includes information related to the updating of the shared digital key, the electronic device  310  may update the shared digital key stored in the electronic device  310 . In various embodiments, the information related to the management of the shared digital key of the electronic device  310  may be transmitted to the first backend server  1010 . For example, the electronic device  310  may revoke or update the shared digital key and transmit, to the first backend server  1010 , information related to a result of the revoking and updating. 
     In various embodiments, in the case of the option 2 scenario, operations  1021  to  1027  may be performed after operation  1013 . At this time, operations  1025  and  1027  may be performed in the same manner as operations  1017  and  1019 . 
     In operation  1021 , the second backend server  1020  may transmit a response message. For example, the second backend server  1020  may transmit the verified response message to the first backend server  1010 . In this case, a mutual authentication procedure between the first backend server  1010  and the second backend server  1020  may be performed. 
     In operation  1023 , the first backend server  1010  may transmit the response message. For example, the first backend server  1010  may transmit, to the electronic device  310 , the response message received from the second backend server  1020  in operation  1021 . In this case, a mutual authentication procedure between the first backend server  1010  and the electronic device  310  may be performed. 
     In operation  1025 , the electronic device  310  may verify the response message. For example, the electronic device  310  may verify information about the shared digital key, response information, or a signature of a sender transmitting the response message, which is included in the response message. 
     In operation  1027 , the electronic device  310  may perform an operation according to the response. That is, the electronic device  310  may perform shared digital key management based on the information included in the verified response message. For example, when the response information of the response message includes information related to the revocation of the shared digital key, the electronic device  310  may revoke the shared digital key stored in the electronic device  310 . When the response information of the response message includes information related to the updating of the shared digital key, the electronic device  310  may update the shared digital key stored in the electronic device  310 . 
     When the digital key management procedure as described with reference to  FIG. 10  is performed in the option 1 scenario and the option 2 scenario, the following operations may be performed. 
     In an embodiment, when the management (e.g. , revocation or updating) of the shared digital key of another user is requested by the owner, a notification about the management of the shared digital key may be transmitted to the electronic device  240  of another user or the backend server  230  for the electronic device of another user. 
     In another embodiment, when the management (e.g. , revocation) of the shared digital key of another user is requested by another user, a notification about the management of the shared digital key may be transmitted to the owner device  100  or the backend server  210  of the owner device. Through the procedures as described above, the digital key management operation initiated or triggered by the second backend server may be performed. 
     An operating method of the electronic device  310  for managing a digital key, according to various embodiments of the present disclosure, may include: receiving a response message to a request message for managing a shared digital key; verifying information included in the received response message; and managing the shared digital key based on the verified information. 
     According to various embodiments of the present disclosure, the request message may include at least one of information about the shared digital key, request information, routing information, or a signature of a device transmitting the request message, and the response message may include at least one of information about the shared digital key, response information, routing information, or a signature of a device transmitting the response message. 
     According to various embodiments of the present disclosure, the request information may include information requesting the shared digital key management, the response information may include a result of management the shared digital key, and the shared digital key management may include at least one of revoking or updating the shared digital key. 
     According to various embodiments of the present disclosure, the revoking of the shared digital key may refer to revocation of the permission to share the shared digital key, and the updating of the shared digital key may refer to updating information about an expiration date of the shared digital key or the permission to use the shared digital key. 
     The operating method of the electronic device  310 , according to various embodiments of the present disclosure, may further include transmitting the information about the shared digital key management to the third electronic device  310 . 
     The request message or the response message according to various embodiments of the present disclosure may be transmitted through a communication method using NFC or a communication method using HTTP. In an embodiment, when a communication method using HTTP is used, the request message or the response message may be transmitted through the first backend server or the second backend server. 
     The operating method of the electronic device  310 , according to various embodiments of the present disclosure, may include: generating a request message for managing a shared digital key; and transmitting the generated request message to the target device  320 . 
     According to various embodiments of the present disclosure, when shared digital key management is initiated or triggered by the first backend server, the request message may be generated by the first backend server, the generated request message may be transmitted to the second backend server, and the response message may be a response message to the request message changed based on the request message transmitted to the second backend server. 
     According to various embodiments of the present disclosure, when shared digital key management is initiated or triggered by the second backend server, the request message may be generated by the second backend server, the generated request message may be transmitted to the target device  320 , and the response message may be a response message to the request message transmitted to the target device  320 . 
     An operating method of the target device  320  for managing a digital key, according to various embodiments of the present disclosure, may include: verifying information included in the request message for managing the shared digital key; generating a response message to the request message based on the verified information; and transmitting the generated response message. 
     The operating method of the target device  320 , according to various embodiments of the present disclosure, may further include receiving the request message for managing the shared digital key. The request message may include at least one of information about the shared digital key, request information, routing information, or a signature of a device transmitting the request message. The response message may include at least one of information about the shared digital key, response information, routing information, or a signature of a device transmitting the response message. 
       FIGS. 11 to 13  illustrates configurations of an electronic device and a target device. 
       FIG. 11  is a diagram illustrating a configuration of an electronic device  310 , according to various embodiments of the present disclosure. In  FIG. 11 , the electronic device  310  may refer to the owner device  100  or the electronic device  240  of another user. 
     Referring to  FIG. 11 , the electronic device  310  may include a processor  1110 , a communicator  1120 , a memory  1130 , a secure element  1150 , and a bus  1140  connecting the elements to each other. However, the electronic device  310  may be implemented by more elements than the elements illustrated in  FIG. 11 . 
     Although  FIG. 11  illustrates that the electronic device  310  includes one processor, embodiments of the present disclosure are not limited thereto, and the electronic device  310  may include a plurality of processors. At least some operations and functions of the processor  1110  may be performed by a plurality of processors. The electronic device  310  illustrated in  FIG. 11  may perform the method for managing the shared digital key, according to various embodiments of the present disclosure, and the descriptions of  FIGS. 3 to 10  may be applied thereto. Therefore, contents overlapping the above description will be omitted. 
     The communicator  1120  may perform wired and/or wireless communication with other devices, servers, or networks. To this end, the communicator  1120  may include a communication module supporting at least one of various wired and/or wireless communication methods. For example, the communication module may be in the form of a chipset, or may be a sticker/barcode (e.g. , a sticker including an NFC tag) including information necessary for communication. 
     The wireless communication may include, for example, at least one of cellular communication, wireless fidelity (Wi-Fi), Wi-Fi Direct, Bluetooth, ultra wide band (UWB), or NFC. The wired communication may include, for example, at least one of universal serial bus (USB) or high definition multimedia interface (HDMI). 
     In an embodiment, the communicator  1120  may include a communication module for short range communication. For example, the communicator  1120  may include a communication module that performs various short range communication such as infrared communication, magnetic secure transmission (MST), and magnetic secure communication, in addition to Wi-Fi, Wi-Fi Direct, Bluetooth, and NFC. 
     Various types of data such as files and programs such as applications may be installed and stored in the memory  1130 . The processor  1110  may access and use data stored in the memory  1130 , or may store new data in the memory  1130 . In an embodiment, programs and data for managing the digital key may be installed and stored in the memory  1130 . However, embodiments of the present disclosure are not limited thereto, and programs and data for managing the digital key may be installed and stored in the secure element  1150 . In an embodiment, information about the shared digital key of another user other than the owner may be stored in the memory  1130 . 
     The secure element  1150  is a secure storage of the electronic device  310  and is a secure area accessible only by an authenticated application. The secure element  1150  may be configured to be separated from a general storage area in a software manner, or may be configured to be physically separated from the memory  1130 . 
     The processor  1110  may control the overall operations of the electronic device  310 , and may include at least one processor such as a central processing unit (CPU) or a graphics processing unit (GPU). The processor  1110  may control other elements included in the electronic device  310  so as to perform the operation for managing the shared digital key. 
     The processor  1110  may execute programs stored in the memory  1130  and the secure element  1150 , may read a stored file, or may store a new file. 
     The bus  1140  is a common data transmission path connecting the communicator  1120 , the memory  1130 , the secure element  1150 , and the processor  1110 . 
     In various embodiments of the present disclosure, the communicator  1120  may receive a response message to the request message for managing the shared digital key. The processor  1110  may verify information included in the received response message and manage the shared digital key based on the verified information. 
     In various embodiments of the present disclosure, the request message may include at least one of information about the shared digital key, request information, routing information, or a signature of a device transmitting the request message. Also, the response message may include at least one of information about the shared digital key, response information, routing information, or a signature of a device transmitting the response message. 
     In various embodiments of the present disclosure, the request information may include information requesting shared digital key management. The response information may include a result of managing the shared digital key. Also, the shared digital key management may include at least one of revocation or updating of the shared digital key. 
     In various embodiments of the present disclosure, the revocation of the shared digital key may include revocation of the permission to share the shared digital key. The updating of the shared digital key may refer to updating information about the expiration date of the shared digital key or the permission to use the shared digital key. 
     In various embodiments of the present disclosure, the processor  1110  may transmit information about the shared digital key management to the third electronic device. At this time, the third electronic device may refer to the owner device  100 , the electronic device  240  of another user, the owner device backend server  210 , the target device backend server  220 , or the backend server  230  for the electronic device of another user. 
     In various embodiments of the present disclosure, the request message or the response message may be transmitted through a communication method using NFC or a communication method using HTTP. In an embodiment, when the communication method using HTTP is used, the request message or the response message may be transmitted through the first backend server or the second backend server. 
     In various embodiments of the present disclosure, the processor  1110  may generate a request message for managing the shared digital key, and the communicator  1120  may transmit the generated request message to the target device. 
     In various embodiments of the present disclosure, when the digital key management is initiated or triggered by the first backend server, the request message may be generated by the first backend server, and the generated request message may be transmitted to the second backend server. The response message may be a response message to the request message changed based on the request message transmitted to the second backend server. 
     According to various embodiments of the present disclosure, when the shared digital key management is initiated or triggered by the second backend server, the request message may be generated by the second backend server, the generated request message may be transmitted to the target device, and the response message may be a response message to the request message transmitted to the target device. 
       FIG. 12  is a diagram illustrating a configuration of a target device  320 , according to various embodiments of the present disclosure. In  FIG. 12 , the target device  320  may refer to the electronic device  11 . 
     Referring to  FIG. 12 , the target device  320  may include a processor  1210 , a communicator  1220 , a memory  1230 , a secure element  1250 , and a bus  1240  connecting the elements to each other. However, the target device  320  may be implemented by more elements than the elements illustrated in  FIG. 12 . 
     Although  FIG. 12  illustrates that the target device  320  includes one processor, embodiments of the present disclosure are not limited thereto, and the target device  320  may include a plurality of processors. At least some operations and functions of the processor  1210  may be performed by a plurality of processors. The target device  320  illustrated in  FIG. 12  may perform the method for managing the shared digital key, according to various embodiments of the present disclosure, and the descriptions of  FIGS. 3 to 10  may be applied thereto. Therefore, contents overlapping the above description will be omitted. 
     The communicator  1220  may perform wired and/or wireless communication with other devices, servers, or networks. To this end, the communicator  1220  may include a communication module supporting at least one of various wired and/or wireless communication methods. For example, the communication module may be in the form of a chipset, or may be a sticker/barcode (e.g. , a sticker including an NFC tag) including information necessary for communication. 
     The wireless communication may include, for example, at least one of cellular communication, wireless fidelity (Wi-Fi), Wi-Fi Direct, Bluetooth, ultra wide band (UWB), or NFC. The wired communication may include, for example, at least one of USB or HDMI. 
     In an embodiment, the communicator  1220  may include a communication module for short range communication. For example, the communicator  1120  may include a communication module that performs various short range communication such as infrared communication, MST, and magnetic secure communication, in addition to Wi-Fi, Wi-Fi Direct, Bluetooth, and NFC. 
     Various types of data such as files and programs such as applications may be installed and stored in the memory  1230 . The processor  1210  may access and use data stored in the memory  1230 , or may store new data in the memory  1230 . In an embodiment, programs and data for managing the digital key may be installed and stored in the memory  1230 . However, embodiments of the present disclosure are not limited thereto, and programs and data for managing the digital key may be installed and stored in the secure element  1250 . In an embodiment, information about the shared digital key of another user other than the owner may be stored in the memory  1230 . 
     The secure element  1250  is a secure storage of the target device  320  and is a secure area accessible only by an authenticated application. The secure element  1250  may be configured to be separated from a general storage area in a software manner, or may be configured to be physically separated from the memory  1230 . 
     The processor  1210  may control the overall operations of the target device  320 , and may include at least one processor such as a CPU or a GPU. The processor  1210  may control other elements included in the target device  320  so as to perform the operation for managing the shared digital key. 
     The processor  1210  may execute programs stored in the memory  1230  and the secure element  1250 , may read a stored file, or may store a new file. 
     The bus  1240  is a common data transmission path connecting the communicator  1220 , the memory  1230 , the secure element  1250 , and the processor  1210 . 
     In various embodiments of the present disclosure, the processor  1210  may verify information included in the request message for managing the shared digital key. The processor  1210  may generate a response message to the request message based on the verified information. The communicator  1220  may transmit the generated response message. 
     In various embodiments of the present disclosure, the communicator  1220  may receive the response message for managing the shared digital key. In this case, the request message may include at least one of information about the shared digital key, request information, routing information, or a signature of a device transmitting the request message, and the response message may include at least one of information about the shared digital key, response information, routing information, or a signature of a device transmitting the response message. 
       FIG. 13  is a diagram illustrating a configuration of a secure element  1150 , according to various embodiments of the present disclosure. 
     Referring to  FIG. 13 , the secure element  1150  may include a communication interface  1310 , a memory  1320 , and a processor  1330 . 
     In various embodiments, the secure element  1150  is a secure storage of the electronic device  310  and is a secure area accessible only by an authenticated application. In an embodiment, the secure element  1150  may include an embedded secure element (eSE), a universal integrated circuit card (UICC), a secure digital card (SD Card), an embedded UICC (eUICC), and/or a trusted execution environment (TEE), and the like. 
     The communication interface  1310  may communicate with a host  101 . In an embodiment, the communication interface  1310  may include at least one of various wired and/or wireless communication interfaces for communicating with the host  101 . The host  101  may be one of devices included in the electronic device  310 , and may include, for example, an application processor (AP), a memory, and the like. The communication interface  1310  may be, for example, a serial interface such as ISO  7816 , USB, inter-integrated circuit (IC), serial peripheral interface (SPI), single wire protocol (SWP), and/or ultra wide band (UWB), or any serial interface commonly used for communication between two hardware devices. Also, the communication interface  1310  may be a wireless interface such as ISO 14443, Zigbee, Bluetooth, or the like, which directly connects an antenna to a hardware device. Furthermore, the communication interface  1310  may be a parallel interface connected to a central bus of the electronic device  310 . In this case, the communication interface  1310  may include a buffer that receives commands and data from the host  101 . 
     Various types of data such as files and programs such as applications may be installed and stored in the memory  1320 . The processor  1330  may access and use data stored in the memory  1320 , or may store new data in the memory  1320 . In an embodiment, programs and data for processing the digital key may be installed and stored in the memory  1320 . 
     The processor  1330  may control the overall operations of the secure element  1150 , and may include at least one processor such as a CPU or a GPU. The processor  1330  may control other elements included in the secure element  1150  to perform operations for processing the digital key. For example, the processor  1330  may execute programs stored in the memory  1320 , may read a stored file, or may store a new file. In an embodiment, the processor  1330  may perform an operation of processing the digital key by executing a program stored in the memory  1320 . 
     On the other hand, the secure element  1150  of  FIG. 11  corresponds to the secure element  1250  of  FIG. 12 . The description of  FIG. 11  may be equally applied to the secure element  1250  of  FIG. 12 . 
     The methods according to the embodiments of the present disclosure, which are described in the claims or the specification, may be implemented as hardware, software, or a combination of hardware and software. 
     When implemented as software, a computer-readable storage medium storing one or more programs (software modules) may be provided. One or more programs stored in the computer-readable storage medium are configured to be executable by one or more processors in an electronic device. One or more programs include instructions that cause the electronic device to execute the methods according to the embodiments of the present disclosure, which are described in the claims or the specification of the present disclosure. 
     One or more programs (software modules, software, etc.) may be stored in RAM, non-volatile memory including flash memory, ROM, electrically erasable programmable read only memory (EEPROM), magnetic disc storage device, CD-ROM, DVD, other types of optical storage devices, or magnetic cassette. Alternatively, one or more programs may be stored in a memory provided by a combination of all or part of these devices. Also, each memory may include a plurality of configured memories. 
     Also, one or more programs may be stored in an attachable storage device that is accessible through a communication network such as Internet, intranet, local area network (LAN), wide LAN (WLAN), or storage area network (SAN), or communication network provided by a combination thereof These storage devices may be connected through an external port to a device that performs the embodiments of the present disclosure. Also, a separate storage on the communication network may access the device that performs the embodiment of the present disclosure. 
     Although specific embodiments have been described in the detailed description of the present disclosure, various modifications may be made without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the above-described embodiments of the present disclosure and should be determined by the appended claims and the equivalents thereof. 
     Block diagrams disclosed in the present disclosure may be interpreted by those of ordinary skill in the art as conceptual representations of circuits for implementing the principles of the present disclosure. Similarly, it will be appreciated by those of ordinary skill in the art that any flow charts, flow diagrams, state transition diagrams, pseudo-codes, and the like may be represented substantially in a computer-readable medium, and a computer or a processor, whether or not explicitly illustrated, represents a variety of processes that may be executed by the computer or the processor. Therefore, the above-described embodiments of the present disclosure may be written as a program that is executable on a computer, and may be implemented in a general-purpose digital computer that operates the program by using a computer-readable recording medium. The computer-readable recording medium includes a storage medium such as a magnetic storage medium (e.g. , read-only memory (ROM), floppy disk, hard disk, etc.) and an optically readable medium (e.g. , compact disc read-only memory (CD-ROM), digital versatile disc (DVD), etc.). 
     Functions of various elements illustrated in the drawings may be provided through the use of dedicated hardware as well as hardware capable of executing software in association with appropriate software. When provided by a processor, such functions may be provided by a single dedicated processor, a single shared processor, or a plurality of individual processors, some of which may be shared. Furthermore, explicit use of the terms “processor” or “controller” should not be construed as referring exclusively to hardware capable of executing software, and the processor or the controller may implicitly include, without limitation, digital signal processor (DSP) hardware, ROM for storing software, random access memory (RAM), and non-volatile storage. 
     In the claims of the present specification, an element expressed as a means for performing a specific function may encompass any method of performing the particular function. Such an element may include a combination of circuit elements that perform a specific function, or any form of software, including firmware or microcode, combined with suitable circuits to perform software for performing the particular function. 
     The indications herein to “an embodiment” of the principles of the present disclosure and various modifications of such expressions mean that a particular feature, structure, characteristic, etc. in connection with this embodiment is included in at least one embodiment of the principles of the present disclosure. Thus, the expression “in an embodiment” and any other modifications disclosed throughout the present specification are not necessarily all referring to the same embodiment. 
     Throughout the present specification, the expression “at least one of A and B” is used to select only the first option A, only the second option B, both the first option A and the second option B. As an additional example, the expression “at least one of A, B, or C” may indicate only the first option A, only the second option B, only the third option C, both the first option A and the second option B, both the first option A and the third option C, both the second option B and the third option C, and all of the first option, the second option, and the third option. Even when more items are listed, it may be clearly interpreted by those of ordinary skill in the art. 
     So far, the preferred embodiments of the present disclosure have been described. 
     All embodiments and conditional examples disclosed throughout the present specification are described with the intent to help those of ordinary skill in the art to understand the principles and concepts of the present disclosure, and those of ordinary skill in the art will appreciate that the present disclosure may be embodied in modified forms without departing from the spirit and scope of the present disclosure. Therefore, the disclosed embodiments should be considered from an explanatory viewpoint rather than a limitative viewpoint. The scope of the present disclosure is shown in the claims rather than the foregoing description, and all differences within the scope equivalent thereto should be construed as falling within the present disclosure.