Information processing system and program

Abstract

To be removed in the case where an authentication key required for an application in a use of a service is not used.SOLUTION: A compound machine 10 includes: an authentication service 24 that authenticates a generated private key using the private key; a key information storage part 18 that stores key information corresponded with an application using the authentication service 24; a secret key provision part 13 that refers the key information in accordance with an acquirement request containing an application ID and an authentication service from the application, and provides the secret key required for starting a use of a cloud service 22 to an acquisition request source; an application survival confirmation part 15 that confirms an existence of the application registered to the key information; and a key information management part 14 that removes the secret key that is not also used from any applications registered to the key information and the key information corresponded to the secret key.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an information processing system and a program. [Background technology]

[0002] Recently, a technology is known in which a service system is formed on the cloud and a service is provided via the Internet to a device installed in an on-premise environment or the like. In such a service system, a technology is known in which the authenticity of a device is confirmed using an authentication key of a public key cryptosystem, that is, a key pair of a public key and a private key, in order to prevent "spoofing" by a fake device. More specifically, the device holds its own private key and has its own public key held on the cloud side, and these key pairs are linked. When an application running on the device executes a process in cooperation with the cloud, the application transmits an authentication request including the private key held by the device to the cloud. When a server on the cloud that provides a cloud service receives the authentication request including the private key, the server authenticates the device using the private key. The application becomes able to use the cloud service by being successfully authenticated by the server. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2008-502251 [Patent Document 2] Patent No. 3775791 Specification Summary of the Invention [Problem to be solved by the invention]

[0004] The life cycles of multiple applications installed in an information processing device are not necessarily the same, and are not necessarily known information. Therefore, when multiple applications use the same authentication key for authentication, it is unclear at what point the authentication key will no longer be used.

[0005] In recent years, the life cycle of authentication keys has become important, and it has become necessary to discard or inactivate keys that are no longer in use at a certain point in time. Therefore, it is desirable to be able to meet this requirement.

[0006] An object of the present invention is to delete an authentication key necessary for an application to use a service when the authentication key is no longer in use. [Means for solving the problem]

[0007] The information processing system of the present invention is equipped with a processor, and when the processor refers to key management information in which an authentication key used for authentication when an application installed on an information processing device uses a service is associated with an application that uses the authentication key, if there is an authentication key that has been uninstalled from the information processing device and is no longer associated with a single application, the processor deletes the authentication key.

[0008] In addition, the key management information is set so that the authentication key is associated with authentication destination information identifying an authentication destination of an application using the authentication key, encryption method information of the authentication key, application identification information of the application using the authentication key, and information on last use date and time of the authentication key by the application, and when an acquisition request for the authentication key from the application includes the authentication destination information and encryption method information of the authentication key, the processor updates the authentication destination information of the authentication key, the encryption method information of the authentication key, and the last use date and time information corresponding to the application identification information of the application with date and time information at the time when the acquisition request was acquired, and when a plurality of authentication keys are associated with one authentication destination information when referring to the key management information, the processor refers to the last use date and time information associated with each of the plurality of authentication keys to identify the latest authentication key from the plurality of authentication keys.

[0009] Furthermore, when the same application identification information is associated with at least two of the plurality of authentication keys associated with one of the authentication destination information, the processor refers to last use date and time information associated with the application identification information and deletes the authentication key that is not the latest among the at least two authentication keys associated with the application identification information.

[0010] The key management information further includes registration date and time information when the authentication key is registered in the key management information, and the processor refers to the registration date and time information to delete the authentication key that has been registered for a predetermined time.

[0011] In addition, when the authentication destination of the application authenticates the application by confirming that the authentication key that the application sends to the service when using the service, which is one of a pair of keys, and the other of the pair of keys that the application holds form a pair, the processor is characterized in that it confirms the validity of the pair of keys by sending the authentication key to the authentication destination before deleting the authentication key to be deleted.

[0012] In addition, when the processor confirms that the pair of keys is valid, the processor holds the authentication key that is to be deleted rather than deleting it.

[0013] In addition, when the processor confirms that the pair of keys is invalid, the processor deletes the authentication key that is determined to be deletable.

[0014] The program of the present invention causes a computer to refer to key management information that associates an authentication key used for authentication when an application installed on an information processing device uses a service with an application that uses the authentication key, and if an authentication key exists that has been uninstalled from the information processing device and is no longer associated with a single application, the computer realizes the function of deleting the authentication key. Effect of the Invention

[0015] According to the invention recited in claim 1, an authentication key required for an application to use a service can be deleted when it is no longer in use.

[0016] According to the invention recited in claim 2, it is possible to select, as a deletion target, an authentication key that is not the latest among the authentication keys authenticated by the authentication destination.

[0017] According to the invention recited in claim 3, it is possible to delete the old authentication key that was used as the authentication key used by the application before switching to the new authentication key.

[0018] According to the invention recited in claim 4, an authentication key that is considered to have become outdated after a predetermined time has elapsed can be automatically deleted.

[0019] According to the invention recited in claim 5, it is possible to check whether or not application authentication is still possible by using a pair of keys including the authentication key to be deleted.

[0020] According to the invention as recited in claim 6, the authentication key can be stored rather than deleted in consideration of cases where the application uses it again.

[0021] According to the invention recited in claim 7, it is possible to delete an unnecessary authentication key that is no longer usable.

[0022] According to the invention recited in claim 8, an authentication key required for an application to use a service can be deleted when it is no longer in use. [Brief description of the drawings]

[0023] [Figure 1] 1 is a diagram showing an overall configuration of a service system and a block configuration of a multifunction peripheral according to a first embodiment. [Diagram 2] FIG. 4 is a diagram showing an example of a data configuration of key information stored in a key information storage unit in the first embodiment. [Diagram 3] 10 is a flowchart showing a service usage process in the first embodiment. [Figure 4] 4 is a flowchart showing a private key management process in the first embodiment. [Diagram 5] FIG. 11 is a diagram showing an example of a data configuration of key information stored in a key information storage unit in the second embodiment. [Figure 6] 6 is a diagram showing an example of settings in the key management table shown in FIG. 5 after a new key algorithm provided by the authentication service is used. FIG. [Figure 7] 13 is a flowchart showing a private key management process in the second embodiment. [Figure 8] FIG. 11 is a diagram showing the overall configuration of a service system and a block configuration of a multifunction peripheral according to a third embodiment. [Figure 9] 13 is a flowchart showing a private key management process in the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[0025] Embodiment 1 FIG. 1 is an overall configuration diagram of a service system in this embodiment. The service system in this embodiment is one form of an information processing system according to the present invention. FIG. 1 shows a configuration in which a multifunction device 10 installed in an on-premise environment and a cloud 20 are connected via a network 2 such as the Internet. The cloud 20 includes a cloud service system 22 that provides predetermined cloud services a to c, and an authentication service system 24 that provides authentication services X and Y using a private key. In the following description, when it is not necessary to distinguish between the cloud services a to c, they will be collectively referred to as "cloud service 22". When it is not necessary to distinguish between the authentication services X and Y, they will be collectively referred to as "authentication service 24".

[0026] In the cloud 20 shown in FIG. 1, three cloud services a to c and two authentication services X and Y are provided, but the number of services provided is not limited to this and may be one or more for each.

[0027] The cloud service 22 is provided by one service server, which is one form of information processing device, or by multiple service servers operating in cooperation with each other. Conversely, one service server provides one or multiple cloud services 22. Typically, one cloud service 22 is provided by one service server.

[0028] The authentication service 24 is provided by one or more service servers, which are a form of information processing device, similar to the cloud service 22. Furthermore, one service server provides one or more authentication services 24. Typically, one authentication service 24 is provided by one service server.

[0029] The service servers providing the services 22 and 24 are virtual server computers formed on the cloud 20. Although the service servers are virtual, they have a CPU, ROM, RAM, storage means, and communication means. The cloud service 22 and the authentication service 24 basically provide the same services as before.

[0030] The multifunction device 10 in this embodiment is a form of an image forming device equipped with various functions such as a printing function, a copying function, a scanning function, etc., and is a device that has an information processing device (also called a "computer"). The multifunction device 10 in this embodiment can be realized with a general-purpose hardware configuration that has existed for a long time. That is, the multifunction device 10 is equipped with a CPU, a ROM, a RAM, a storage unit such as a hard disk drive (HDD) that stores image data, a mailbox, etc., an operation panel as a user interface, a network interface that connects to a network 2 such as the Internet, a scanner, a print engine, etc. that are necessary to provide various functions.

[0031] Furthermore, the multifunction device 10 in this embodiment is equipped with an HSM (Hardware Security Module) such as a TPM (Trusted Platform Module) as a means for storing keys. The HSM is a hardware device with enhanced tamper-resistant functions that keeps the encryption process secure by generating, protecting, and managing keys used for encrypting and decrypting data and creating digital signatures and certificates, and is fixed to the board. The service system in this embodiment can be used by multiple multifunction devices 10, but since each multifunction device 10 has the same functions described below, only one is shown in FIG. 1.

[0032] 1 further shows an example of functional blocks of the multifunction device 10 in this embodiment. The multifunction device 10 in this embodiment has a key storage unit 11, an application execution unit 12, a private key providing unit 13, a key information management unit 14, an application existence confirmation unit 15, a notification unit 16, an application storage unit 17, and a key information storage unit 18. Note that the multifunction device 10 naturally provides multiple functions such as a printing function and a scanning function, but in this embodiment, functional blocks that are not used in the description are omitted from the figure.

[0033] The key storage unit 11 is realized by the above-mentioned HSM, and stores at least the private key. Meanwhile, the multifunction device 10 generates a key pair of a public key and a private key of a public key cryptosystem as a pair of information that can prove that they form a pair, in order to confirm the authenticity of the device itself. Then, the private key is stored in the key storage unit 11 as described above. On the other hand, the public key is stored in the authentication service system 24.

[0034] Incidentally, an authentication key is a key used for authentication. A private key and a public key are formed as a key pair and used together. Therefore, in the present embodiment, the authentication key may refer to the key pair described above in a broad sense, or may refer to a private key used by the multifunction device 10 for authentication in a narrow sense.

[0035] The application execution unit 12 executes applications that are in an executable state by being installed in the multifunction device 10. When an application starts using any of the cloud services 22, it transmits an authentication request including a private key stored in the key storage unit 11 to the cloud service 22. In response to a request to obtain a private key from an application, the private key providing unit 13 provides the corresponding private key to the application that has made the request.

[0036] The key information storage unit 18 stores key information, which will be described later, and the key information management unit 14 manages the registration, update, deletion, etc. of the key information. The application existence confirmation unit 15 confirms the existence of the application set in the key information. "Existing" means that the application is in an executable state due to being installed in the multifunction device 10. On the other hand, "not existing" means that the application has been deleted from the multifunction device 10, for example by being uninstalled, and is not in an executable state.

[0037] The notification unit 16 notifies the administrator of the multifunction device 10 that the private key has been deleted, etc., as will be described in detail later. Alive applications are stored in the application storage unit 17. Strictly speaking, an application becomes executable when it is loaded into RAM, but in this embodiment, if an application is stored in the application storage unit 17, it is determined that the application is in an executable state, i.e., is alive.

[0038] Fig. 2 is a diagram showing an example of the data structure of key information stored in key information storage unit 18 in this embodiment. As shown in Fig. 2, key information can be expressed in a table format. Therefore, in the following description, both key information and the key management table correspond to key management information, but in the following description, it is assumed that key information corresponding to each private key is managed in the key management table.

[0039] The key information is set by associating a private key identification information (hereinafter, "key ID") with an authentication service and an application ID. In the authentication service, identification information of the authentication service 24 is set as authentication destination information that specifies the authentication destination that performs authentication using the private key. In the example shown in FIG. 1, the identification information of the authentication service 24 is "X" or "Y". In the application ID, identification information of an application that uses the private key as an authentication key in the authentication service 24 is set.

[0040] In the example of key information settings shown in Figure 2, it can be seen that the private key with key ID "keyX1" is used for authentication of applications "app A" and "app B" by authentication service X. To this end, the public key paired with private key "keyX1" needs to be associated with authentication service X and stored and managed. Similarly, it can be seen that the private key with key ID "keyY1" is used for authentication of application "app C" by authentication service Y. To this end, the public key paired with private key "keyY1" needs to be associated with authentication service Y and stored and managed.

[0041] Each of the components 11 to 16 in the multifunction device 10 is realized by the cooperative operation of a computer installed in the multifunction device 10 and a program running on a CPU installed in the computer. Also, each of the storage units 17 and 18 is realized by a HDD installed in the multifunction device 10. Alternatively, a RAM or an external storage means may be used via a network.

[0042] Furthermore, the programs used in the present embodiment can be provided not only by communication means, but also by being stored in a computer-readable recording medium such as a USB memory. The programs provided from the communication means or recording medium are installed in a computer, and various processes are realized by the computer's CPU sequentially executing the programs.

[0043] Next, the operation of this embodiment will be described. First, the process when an application uses cloud service 22 will be described with reference to the flowchart shown in FIG.

[0044] Incidentally, the application in this embodiment is an application for providing a user with a predetermined cloud service 22 in cooperation with the cloud service 22. The cloud service 22 requests authentication of the multifunction device 10 to the authentication service 24, and the authentication service 24 to which the request is made is specified by contract. Therefore, the administrator of the multifunction device 10 knows the cloud service 22 with which each application operates in cooperation and the authentication service 24 used to authenticate the multifunction device 10, and the application recognizes the cloud service 22 and authentication service 24 to be used.

[0045] When any application is launched, the application execution unit 12 starts executing the application. The application first makes a request to the private key providing unit 13 to obtain a private key required to use the cloud service 22. This request includes its own application ID and the authentication service 24 to be used.

[0046] When private key provider 13 receives an acquisition request sent from application execution unit 12 (step S101), it checks whether key information corresponding to the pair of application ID and authentication service 24 included in the acquisition request is registered in the key management table. If the key information is registered, it means that a private key corresponding to the authentication service has been generated and exists (Y in step S102), so private key provider 13 refers to the key information to identify a private key corresponding to the pair of application ID and authentication service 24, retrieves the private key from key storage unit 11, and provides it to the application that has made the acquisition request (step S106).

[0047] On the other hand, if the key information has not been registered, it is determined that a key pair associated with the authentication service 24 has not yet been generated. In this case (N in step S102), the key information management unit 14 generates a key pair (step S103) and executes an initial registration process (step S104).

[0048] The administrator of the multifunction device 10 is given authentication information consisting of an ID and a password, or a customer code, by the authentication service 24 at the time of contract. Therefore, in the initial registration process, the key information management unit 14 authenticates that the administrator is a legitimate administrator and the multifunction device 10 by having the administrator input and set the authentication information or customer code from the operation panel. Since the multifunction device 10 needs to access the authentication service 24, the acquisition request from the application may specify a URL that can identify the access destination, i.e., the authentication destination, as identification information of the authentication service 24. In this case, in the key management table shown in FIG. 2, "X" or "Y" corresponding to the identification information of the authentication service 24 is set as the authentication destination information included in the key information for convenience, but a URL may also be set.

[0049] Then, when the key information management unit 14 succeeds in authenticating the administrator, it stores the private key of the generated key pair in the key storage unit 11. On the other hand, the public key that forms a pair with the stored private key is transmitted to the authentication service 24 and registered therein.

[0050] In this manner, the key information management unit 14 generates key information by associating the key ID of the generated private key with the authentication service 24 and application ID included in the acquisition request, and registers the generated key information in the key management table (step S105). After that, the private key provision unit 13 refers to the key information, retrieves the private key corresponding to the authentication service 24 and application ID included in the acquisition request from the key storage unit 11, and provides the private key to the application that has made the acquisition request (step S106).

[0051] In this way, when the application obtains a private key in response to a request for a private key made when starting to use the cloud service 22, the application attaches a digital signature using the private key and requests the cloud service 22 to use the service.

[0052] When the application that has made the acquisition request is application A, application A specifies authentication service X and sends the acquisition request to private key providing unit 13, in which case private key providing unit 13 will provide "keyX1" according to the example setting of the key management table shown in Fig. 2. When the application that has made the acquisition request is application C, application C specifies authentication service Y and sends the acquisition request to private key providing unit 13, in which case private key providing unit 13 will provide "keyY1" according to the example setting of the key management table shown in Fig. 2.

[0053] If the key information corresponding to “keyY1” is not registered in the key management table when an acquisition request is received from application C, the key information management unit 14 generates a key pair including the private key “keyY1”, executes the initial registration process described above, and registers the key information of the private key “keyY1” in the key management table.

[0054] When the cloud service 22 receives a service usage request from the multifunction device 10, it requests the corresponding authentication service 24 to perform authentication using the private key included in the service usage request. If the application and, ultimately, the multifunction device 10 are successfully authenticated, the cloud service 22 starts usage in response to the request from the application. In this way, the application becomes able to use the cloud service 22.

[0055] As described above, since a private key is necessary when an application uses cloud service 22, if there is a possibility that the private key will be used by an application, it needs to be managed in the key management table and stored in key storage unit 11. On the other hand, a private key becomes unnecessary after it is no longer used by any application. Therefore, it is not preferable from the viewpoint of security to continue to hold a private key even after it is no longer necessary. Therefore, it is desirable to delete the private key. The private key management process in this embodiment for holding or deleting such a private key will be described with reference to the flowchart shown in FIG. 4.

[0056] The private key management process is performed at a predetermined timing, for example, when the multifunction device 10 is started up, or as a regular process after the start-up.

[0057] When the program for the private key management process is started, the application existence confirmation unit 15 confirms the existence of each application registered in the key management table. To this end, the application existence confirmation unit 15 identifies one application that is not being processed from the key management table (step S121). When there is no application that is not being processed (Y in step S122), the process ends.

[0058] With reference to the application ID item in the key management table, if there is an application that has not been processed (N in step S122), the application existence confirmation unit 15 confirms the existence of the identified application. Specifically, the application existence confirmation unit 15 searches the application storage unit 17, and if the application has been deleted by uninstallation or the like, it is determined that the application is not alive, and if the application is stored without being deleted, it is determined that the application is alive.

[0059] If the application is confirmed to be alive (Y in step S123), the private key registered in the key management table in association with that application may still be in use, so in this case the process returns to step S121 and moves to the next unprocessed application.

[0060] On the other hand, if the existence of the application cannot be confirmed (N in step S123), the application existence confirmation unit 15 confirms whether or not another application is set in the key information corresponding to the application. If another application is set in the key information (Y in step S124), the key information will be referenced when there is an acquisition request from the other application, so the application existence confirmation unit 15 instructs the key information management unit 14 to delete the application ID of the application to be processed from the key information. In response to this instruction, the key information management unit 14 deletes the corresponding application ID (step S127).

[0061] On the other hand, if the key information corresponding to the application being processed does not include any application other than the application (N in step S124), it can be determined that the private key managed by the key information is no longer used by any application. Therefore, the application existence confirmation unit 15 instructs the key information management unit 14 to delete the key information. In response to this instruction, the key information management unit 14 deletes the corresponding key information and also deletes the private key stored by the key storage unit 11 (step S125).

[0062] When the private key and its key information are deleted in this manner, the notification unit 16 notifies the administrator of the multifunction device 10, etc., that the private key has been deleted in response to an instruction from the key information management unit 14 (step S126). This allows the administrator to know that the notified private key has been deleted.

[0063] According to the example of the key management table settings shown in Fig. 2, when the key management process is executed after application A is uninstalled, the private key "keyX1" used by application A may still be used by application B, so the key information of "keyX1" is not deleted. On the other hand, when the key management process is executed after application C is uninstalled, the private key "keyY1" used by application C will no longer be associated with any application as the association with application C is dissolved, so the key information of "keyY1" will be deleted.

[0064] According to this embodiment, it is possible to quickly delete a private key that is no longer used by an application as described above. If it is desired to delete a private key quickly, the above-mentioned private key management process can be executed at relatively short intervals. The execution interval of the private key management process can be determined according to the operation.

[0065] Embodiment 2 As described in the above embodiment 1, a key pair consisting of a private key and a public key is a pair of information that can be proven to form a pair. Also, key pairs of new encryption methods that improve security strength have been developed. In this embodiment, in addition to the above embodiment 1, attention is paid to the encryption method of the authentication key.

[0066] The system configuration and the block configuration of the multifunction device 10 in this embodiment may be the same as those in the first embodiment shown in Fig. 1. In this embodiment, the data structure of the key information is different from that in the first embodiment.

[0067] Fig. 5 is a diagram showing an example of the data configuration of key information stored in the key information storage unit 18 in this embodiment. As shown in Fig. 5, the key information in this embodiment is set by further associating a key algorithm as encryption method information and a last use date as last use date information with the key information in embodiment 1. The name of an algorithm that can identify the encryption method adopted by the private key is set as the key algorithm. The last use date is information associated with each application and indicates the date on which the private key was most recently used by the application. Since detailed information that specifies the use date and time of the private key in units of hours and minutes is not necessary, in this embodiment, the last use date and time information is managed in units of days.

[0068] Next, the operation of this embodiment will be described, but the process when using the service is basically the same as in the first embodiment. However, in this embodiment, a key algorithm is further included in the request for a private key from the application. In accordance with this difference, the application includes an application ID, authentication destination information, and a key algorithm in the request for a private key. The private key providing unit 13 refers to the key management table shown in FIG. 5 and provides a private key corresponding to the application ID, authentication destination information, and key algorithm included in the request, and the key information managing unit 14 updates the last use date corresponding to the authentication destination information, key algorithm, and application ID included in the request with the date and time information when the request was acquired.

[0069] As in the first embodiment, when starting to use the cloud service 22, the application requests the cloud service 22 to use the service by attaching a digital signature using the private key acquired in response to the acquisition request.

[0070] If the application making the request is application A, application A sends a request including authentication service X and key algorithm “algV10”, and the private key providing unit 13 provides “keyX1” by referring to the key management table shown in FIG. 5.

[0071] Next, application A uses "keyX1" to create a digital signature, and requests the use of cloud service a by adding the digital signature. As in the first embodiment, authentication service X verifies the authenticity of multifunction device 10 using the digital signature received from cloud service a and the public key it holds. If authentication is successful, authentication service X returns the authentication result to cloud service a. At this time, if authentication service X has started using a new key algorithm "algV20", it also returns a warning message recommending a change to the new key algorithm. Note that if authentication service X is in the transition period to the new key algorithm, it returns the warning message as described above, allows the use of the key algorithm "algV10", and makes authentication successful.

[0072] If the authentication is successful, cloud service A starts providing the service, but returns a warning message to application A along with the successful authentication.

[0073] When application A receives the warning message, it checks whether its own application has the ability to process the key algorithm "algV20". If it has the processing ability, it can process the next private key acquisition request so that "algV20" is included as the key algorithm. If it does not have the processing ability, it will use the key algorithm "algV10" if it is within the key algorithm transition period, and hope for an upgrade to have the processing ability of "algV20". For this purpose, the notification unit 16 may display on the operation panel or notify the administrator of the multifunction device 10 by email that the key algorithm used in the authentication service X has been changed in response to application A receiving the warning message. It is preferable for the administrator who receives this notification to plan an upgrade of application A within the transition period.

[0074] However, when the private key providing unit 13 receives an acquisition request including the key algorithm "algV20", key information corresponding to "algV20" has not yet been generated. Therefore, the key information managing unit 14 generates a key pair as described in the first embodiment with reference to Fig. 3, generates key information by associating the generated private key "keyX2" with the authentication service X, the key algorithm "algV20", the application A, and the last use date, and registers the generated key information in the key management table. An example of the settings of the key management table after registration is shown in Fig. 6.

[0075] The private key management process in this embodiment will be described below with reference to the flowchart shown in Fig. 7. Note that the same processes as those in the first embodiment are given the same step numbers, and descriptions thereof will be omitted as appropriate.

[0076] According to the example of the key information setting in FIG. 6, multiple private keys “keyX1”, “keyX2” are associated with the authentication service X, and the same application A is associated with each of the multiple private keys “keyX1”, “keyX2”, which is different from the first embodiment. Therefore, in this embodiment, a process based on this difference will be described.

[0077] Focusing on application A, if the existence of application A is confirmed (Y in step S123), if application A is linked to only one private key as shown in FIG. 2 (N in step S201), the process proceeds to step S124 and continues processing in the same manner as in embodiment 1.

[0078] As in the example of the key management table settings shown in FIG. 6, when application A is linked to multiple private keys "keyX1" and "keyX2" (Y in step S201), the key information management unit 14 refers to the last usage date of each of the multiple private keys for application A and identifies the latest private key from among the multiple authentication keys. In other words, one or more older private keys other than the latest one are identified (step S202). After that, the process can be continued in the same manner as in the first embodiment.

[0079] 6, it can be determined that the private key "keyX1" is older than the private key "keyX2." Since the private key "keyX1" is still linked to the application B, the key information management unit 14 only deletes the application A from the key information of the private key "keyX1," and does not delete the key information itself (Y in step S124, S127).

[0080] In this embodiment, the private key associated with the older last usage date in one application is considered to be the old private key. Therefore, although application A is associated with the private keys "keyX1" and "keyX2" as described above, from the viewpoint of security, the older private key "keyX1" is not used retroactively, and the application ID of the application is deleted from the key information corresponding to the private key other than the one that is not the latest.

[0081] However, since the use of old private keys is permitted during the transition period of the key algorithm, it is logically possible that old private keys will be used. Therefore, since the old and new private keys do not always match the new and old dates of the last use of the private keys by the application, it may become impossible to correctly determine whether the private key is new or old based on the last use date included in the key information.

[0082] Therefore, the date on which the private key was first registered in the key management table may be set as registration date and time information in the key information of the private key. In this way, instead of the last use date of the application as described above, the registration date and time information may be referenced to determine whether the private key is new or old.

[0083] However, during the transition period of the key algorithm, the old and new key algorithms and the old and new private keys will not always match. This is because it is conceivable that when an application that is not compatible with the private key "keyX2" uses authentication service X for the first time, the private key "keyX1" will be used. However, assuming that they match in terms of private key operation, the old and new key algorithms are determined using information obtainable by the multifunction device 10. If it were possible to obtain information that could identify the start date of use of the key algorithm from the authentication service 24, the registration date and time information may be set based on that information.

[0084] Furthermore, the key information management unit 14 may refer to the registration date and time information and delete a private key that has been registered in the key management table for a predetermined period of time. The predetermined period of time may be set according to, for example, a transition period of the key algorithm.

[0085] By automatically deleting the private key after a certain period of time has passed, it is possible to promote the transition to authentication using a new key algorithm. For example, in the example of the key management table settings shown in Fig. 6, there is a possibility that the key information corresponding to the old private key "keyX1" will be forcibly deleted. If this happens, application B will no longer be able to be authenticated by authentication service X.

[0086] If application B does not support the key algorithm "algV20", and application B specifies the private key "keyX1" in an acquisition request during the transition period of the key algorithm, the key information management unit 14 executes the initial registration process to regenerate a private key corresponding to the key algorithm "algV10" and generate key information. This allows application B to be authenticated by authentication service X during the transition period. In this case, the notification unit 16 may notify the administrator that an acquisition request including an old key algorithm has been made.

[0087] Once the key algorithm transition period has elapsed, application B will no longer be able to receive authentication from authentication service X. In this case, application B needs to be updated to support the new key algorithm "algV20." It is expected that the administrator will update application B within the transition period.

[0088] Embodiment 3 8 is a diagram showing the overall configuration of the service system according to the present embodiment. The service system according to the present embodiment has a configuration in which a key validity checking unit 19 is added to the multifunction device 10 according to the first embodiment. When the authentication service 24, which is the authentication destination of the application, authenticates the application by checking that the private key transmitted to the cloud service 22 when the application uses the cloud service 22 and the public key held by the application form a pair, the key validity checking unit 19 checks the validity of the key pair before deleting the private key to be deleted. The key validity checking unit 19 is realized by the cooperative operation of a computer mounted on the multifunction device 10 and a program running on a CPU mounted on the computer.

[0089] As described in each of the above embodiments, a private key is automatically deleted when it is no longer used by an application or when a predetermined time has elapsed since the key algorithm was started to be used. Even if an application corresponding to an automatically deleted private key is still active, the key information management unit 14 will not become unable to receive authentication by the authentication service 24 if it generates a new key pair in response to a request for a private key from the application and performs an initial registration process.

[0090] However, in order for an application to be able to be authenticated by the authentication service 24, it is necessary to carry out an initial registration process including the registration of a public key to the authentication service 24 as described above. If authentication using a public key stored and managed in the authentication service 24 is still valid, it may not be necessary to delete the private key paired with that public key, even if it is no longer used by any application, so that it can be reused in the future. In this way, it is possible to avoid carrying out the initial registration process that would otherwise be required when deleting a private key.

[0091] Therefore, in this embodiment, a key validity confirmation unit 19 is provided so that, when a private key is to be deleted, whether authentication using the private key is possible is confirmed before the private key is deleted.

[0092] Next, the operation of this embodiment will be described, but the processing when using the service is basically the same as in embodiment 1. In this embodiment, the contents of the private key management processing are slightly different from those in embodiments 1 and 2. The private key management processing in this embodiment will be described below using the flowchart shown in FIG. 9. Note that the same processing as in embodiment 1 will be assigned the same step numbers and the description will be omitted as appropriate. Here, the explanation will be given using the key management table shown in FIG. 2.

[0093] For example, suppose that application C is uninstalled before the private key management process is performed. According to the example of the settings in the key management table shown in Fig. 2, the private key "keyY1" corresponding to application C is not associated with any application other than application C (N in steps S121 and S122, N in S123, and N in S124), so in the first embodiment, the private key "keyY1" is deleted in step S125.

[0094] In this embodiment, the validity of the key pair is confirmed before deleting the private key "keyY1". That is, the key validity confirmation unit 19 requests authentication using the private key "keyY1" by transmitting the private key "keyY1" to an authentication service Y that can be specified from the key information (step S301).

[0095] The authentication service Y attempts authentication using the sent private key "keyY1". If the authentication service Y still holds the public key paired with the private key "keyY1", the authentication is successful, but if the authentication service Y no longer holds the public key, the authentication fails. For example, the authentication service Y is considered to hold the public key if it is within the contract period with the multifunction device 10. The authentication service Y returns the result of the authentication it performed in response to an authentication request from the key validity confirmation unit 19.

[0096] When an authentication result is returned from the authentication service Y in response to the authentication request, the key information management unit 14 performs the following process. That is, if the authentication is successful (Y in step S302), it is determined that the authentication using the private key "keyY1" is still valid, and the application, in this example, application C, is deleted from the key information of the private key "keyY1" (step S303). As a result, the key information of the private key "keyY1" is held without being deleted from the key management table with the data item of the application ID being blank. In this state, when the private key providing unit 13 receives a request to obtain a private key with authentication service Y specified from any application, the private key "keyY1" linked to authentication service Y can be provided to the application that made the acquisition request without performing an initial registration process.

[0097] On the other hand, if the authentication has failed (N in step S302), the key information management unit 14 determines that the authentication using the private key "keyY1" has become invalid. As a result, the key information management unit 14 deletes the key information of "keyY1" that was determined to be deletable but for which deletion is pending, and deletes the private key "keyY1" stored by the key storage unit 11 (step S125).

[0098] The notification unit 16 notifies the administrator of the multifunction device 10 or the like of the results of the above-mentioned processing by the key information management unit 14 (step S126).

[0099] According to this embodiment, as described above, it is possible to take into consideration the validity of the private key to be deleted and determine whether or not to actually delete it.

[0100] The above-described embodiments may be implemented in appropriate combination.

[0101] In the above embodiments, the term "processor" refers to a processor in a broad sense, including general-purpose processors (e.g., CPU: Central Processing Unit, etc.) and dedicated processors (e.g., GPU: Graphics Processing Unit, ASIC: Application Specific Integrated Circuit, FPGA: Field Programmable Gate Array, programmable logic device, etc.).

[0102] In addition, the operations of the processor in the above embodiments may be performed not only by one processor, but also by multiple processors located at physically separate locations working together. The order of the operations of the processor is not limited to the order described in the above embodiments, and may be changed as appropriate.

[0103] (Additional Note) (((1))) A processor is provided. The information processing system is characterized in that the processor, when referring to key management information that associates an authentication key used for authentication when an application installed on an information processing device uses a service with an application that uses the authentication key, deletes an authentication key if there is an authentication key that has been uninstalled from the information processing device and is no longer associated with any application. (((2))) In the key management information, the authentication key is set in association with authentication destination information specifying an authentication destination of an application using the authentication key, encryption method information of the authentication key, application identification information of the application using the authentication key, and last use date and time information of the authentication key by the application, The processor, when the request to obtain the authentication key from the application includes authentication destination information of the authentication key and encryption method information of the authentication key, updating last use date and time information corresponding to the authentication destination information of the authentication key, the encryption method information of the authentication key, and the application identification information of the application with date and time information at the time the request to obtain the authentication key was obtained; When a plurality of authentication keys are associated with one piece of authentication destination information when referring to the key management information, the latest authentication key is identified from among the plurality of authentication keys by referring to last use date and time information associated with each of the plurality of authentication keys. 1. The information processing system according to claim 1, (((3))) The information processing system described in (((2))) is characterized in that, when the same application identification information is associated with at least two of the plurality of authentication keys associated with one of the authentication destination information, the processor refers to last use date and time information associated with the application identification information and deletes the authentication key that is not the latest of the at least two authentication keys associated with the application identification information. (((4))) the key management information associates the authentication key with registration date and time information when the authentication key was registered in the key management information, The information processing system described in any one of ((1)) to (((3))) is characterized in that the processor refers to the registration date and time information and deletes the authentication key that has been registered for a predetermined time. (((5))) When an authentication destination of the application authenticates the application by confirming that the authentication key that the application transmits to the service when using the service and is one of a pair of keys, and the other of the pair of keys that the application holds form a pair, The information processing system according to any one of ((1)) to (((4))), characterized in that the processor verifies the validity of the pair of keys by sending the authentication key to the authentication destination before deleting the authentication key to be deleted. (((6))) The information processing system described in (((5))) is characterized in that when the processor confirms that the pair of keys is valid, it retains the authentication key that was to be deleted rather than deleting it. (((7))) The information processing system described in ((5)) is characterized in that, when the processor confirms that the pair of keys is invalid, it deletes the authentication key that is determined to be deletable. (((8))) On the computer, a function of deleting an authentication key when, upon referencing key management information in which an authentication key used for authentication when an application installed in an information processing device uses a service is associated with an application using the authentication key, and when an authentication key exists that is uninstalled from the information processing device and is no longer associated with any application, the authentication key is deleted; A program to achieve this.

[0104] According to the invention described in (((1))), an authentication key required for an application to use a service can be deleted when the application is no longer in use. According to the invention described in (((2))), it is possible to select, as a deletion target, an authentication key that is not the latest among the authentication keys authenticated by the authentication destination. According to the invention described in (((3))), it is possible to delete an old authentication key that was used before an application is switched to a new authentication key. According to the invention described in (((4))), an authentication key that is deemed to have become outdated after a predetermined time has passed can be automatically deleted. According to the invention described in (((5))), it is possible to check whether or not authentication of an application is still possible by using a pair of keys including the authentication key to be deleted. According to the invention described in (((6))), it is possible to store the authentication key rather than deleting it, taking into consideration cases in which the application may reuse the authentication key. According to the invention described in (((7))), it is possible to delete unnecessary authentication keys that are no longer usable. According to the invention described in ((8)), an authentication key necessary for an application to use a service can be deleted when the application is no longer in use. [Explanation of symbols]

[0105] 2 network, 10 multifunction device, 11 key storage unit, 12 application execution unit, 13 private key provision unit, 14 key information management unit, 15 application existence confirmation unit, 16 notification unit, 17 application storage unit, 18 key information storage unit, 19 key validity confirmation unit, 20 cloud, 22 cloud service system, 24 authentication service system.

Claims

1. A processor is provided. The information processing system is characterized in that, when the processor refers to key management information that corresponds an authentication key used for authentication when an application installed on an information processing device uses a service to an application that uses the authentication key, if there is an authentication key that has been uninstalled from the information processing device and is no longer associated with a single application, the processor deletes the authentication key.

2. In the key management information, the authentication key is set in association with authentication destination information specifying an authentication destination of an application using the authentication key, encryption method information of the authentication key, application identification information of the application using the authentication key, and last use date and time information of the authentication key by the application, The processor, when the request to obtain the authentication key from the application includes authentication destination information of the authentication key and encryption method information of the authentication key, updating last use date and time information corresponding to the authentication destination information of the authentication key, the encryption method information of the authentication key, and the application identification information of the application with date and time information at the time the request to obtain the authentication key was obtained; When a plurality of authentication keys are associated with one piece of authentication destination information when referring to the key management information, the latest authentication key is identified from among the plurality of authentication keys by referring to last use date and time information associated with each of the plurality of authentication keys.

2. The information processing system according to claim 1 .

3. The information processing system according to claim 2, characterized in that, when the same application identification information is associated with at least two of the plurality of authentication keys associated with one of the authentication destination information, the processor refers to last use date and time information associated with the application identification information and deletes the authentication key that is not the latest among the at least two authentication keys associated with the application identification information.

4. the key management information associates the authentication key with registration date and time information when the authentication key was registered in the key management information, 2. The information processing system according to claim 1, wherein the processor refers to the registration date and time information and deletes the authentication key for which a predetermined time has elapsed since registration.

5. When an authentication destination of the application authenticates the application by confirming that the authentication key that the application transmits to the service when using the service and is one of a pair of keys, and the other of the pair of keys that the application holds form a pair, The information processing system according to claim 1, characterized in that the processor verifies the validity of the pair of keys by sending the authentication key to the authentication destination before deleting the authentication key to be deleted.

6. 6. The information processing system according to claim 5, wherein the processor holds the authentication key that is to be deleted, rather than deleting it, when the processor confirms that the pair of keys is valid.

7. 6. The information processing system according to claim 5, wherein the processor deletes the authentication key that is determined to be deletable when it is determined that the pair of keys is invalid.

8. On the computer, a function of deleting an authentication key when, upon referencing key management information in which an authentication key used for authentication when an application installed in an information processing device uses a service is associated with an application using the authentication key, and when an authentication key exists that is uninstalled from the information processing device and is no longer associated with any application, the authentication key is deleted; A program to achieve this.

Images