JP5826910B2 - Communication apparatus and key management method - Google Patents

Description

  Embodiments described herein relate generally to a communication device and a key management method.

  A research project related to quantum cryptography communication called SECOQC (Secure Communication based on Quantum Cryptography) is known. In SECOQC, a function for performing key exchange based on random numbers generated by quantum key distribution (QKD) and distributed and accumulated in a plurality of nodes, and Q3P (Quantum Point to Point Protocol) Technologies such as the protocol named are proposed.

  QKD is a method for realizing the advancement of next-generation communication security, and the security of the service itself is also important. For example, QKD is a revolutionary technology that can provide an absolutely secure communication environment.

Kollmitzer C., Pivk M. (Eds.), Applied Quantum Cryptography, Lect.Notes Phys. 797 (Springer, Berlin Heidelberg 2010), p155-p168, DOI 10.1007 / 978-3-642-04831-9

  However, in the prior art, the absolute safety of communication using QKD cannot be realized unless the security of the encryption key generated in the system using QKD is ensured. In particular, an attack in which an encryption key stored inside is leaked due to intrusion from a network, such as an intrusion from a communication node that provides an encryption key and a route for delivering a key to a service, can be considered. In other words, countermeasures against so-called cyber attacks are an issue.

  The communication apparatus according to the embodiment includes a key storage unit, a reception unit, an analysis unit, a generation unit, and an access control unit. The key storage unit stores the encryption key. The receiving unit receives a message. The analysis unit analyzes whether or not the message includes an access request for the encryption key. The generation unit generates request information for requesting access to the encryption key requested by the access request when the message includes an access request. The access control unit controls access to the encryption key based on the request information.

The figure which shows an example of the network structure of an encryption communication system. The network block diagram of the encryption communication system of 1st Embodiment. The block diagram which shows the structure of the node of 1st Embodiment. FIG. 5 is a sequence diagram of service use processing according to the first embodiment. The block diagram of the communication control part of 1st Embodiment. The flowchart of the key access process in 1st Embodiment. The block diagram of the node of the modification 1. FIG. The block diagram of the node of the modification 2. FIG. The hardware / software block diagram of the node of 1st Embodiment. The conceptual diagram in the case of managing a link key and an application key in multiple layers. The figure which shows an example of the management information used in order to implement | achieve multilayering. The block diagram of the node which modularized encryption key management of each hierarchy. The block diagram which shows the structure of the node of 2nd Embodiment. The block diagram which shows the structure of the node of 3rd Embodiment. The block diagram which shows the structure of the node of 4th Embodiment.

  Exemplary embodiments of a communication apparatus according to the present invention will be explained below in detail with reference to the accompanying drawings.

(First embodiment)
The communication device (node) according to the first embodiment is configured so that the encryption key cannot be directly accessed from the external network.

  FIG. 1 is a diagram illustrating an example of a network configuration of an encryption communication system. Because of the importance of information communication, encryption communication is performed between a plurality of applications (application 200a, application 200c) to ensure communication safety using encryption (use of application key).

  The encryption method used in encryption communication and the key generation method used for encryption also evolve in accordance with advances in technology and computers. For example, QKD is attracting attention as a means for providing unconditionally safe communication. QKD can be used as a function (service) for providing an encryption key for performing encrypted communication. Such a service (encryption key generation service) is configured independently of data encryption communication. Such a configuration makes it possible to provide advanced encryption communication.

  FIG. 2 is a diagram illustrating an example of a network configuration of the cryptographic communication system according to the first embodiment. FIG. 2 illustrates a network configuration example of a communication system that includes an encryption key generation service independent of data encryption communication.

  Even in such a cryptographic communication system, the cryptographic key provided by the cryptographic key generation service is exposed to various risks. For example, there are risks such as eavesdropping on the communication path, unauthorized access to the node 100, and inappropriate activation of the application 200. QKD reliably detects wiretapping on the communication path and makes it impossible, but does not prevent unauthorized access to the node 100. Therefore, at the system level, the value of QKD that guarantees unconditional safety may not be fully utilized.

  Therefore, in the present embodiment, in such an encryption key generation service, it is possible to ensure the safety of the generated encryption key even when connected to a network for communication with an existing communication system.

  As shown in FIG. 2, the cryptographic communication system according to the present embodiment includes nodes 100a to 100c as communication devices and applications 200a and 200c.

  When it is not necessary to distinguish the nodes 100a to 100c, the node 100 may be simply referred to as a node 100. When it is not necessary to distinguish between the applications 200a and 200c, the application 200a may be simply referred to as an application 200. The number of nodes 100 is not limited to three. Further, the number of applications 200 is not limited to two. Further, the application 200 may be realized integrally with the node 100 or may be realized as a terminal independent of the node.

  Each of the nodes 100a to 100c has a function of generating and sharing a random number with an opposite node, and a function of performing encrypted communication on a link using the generated random number as a link key.

The node 100 may have a function of generating a random number independently of the link and a function of transmitting the generated random number to another node. Hereinafter, an example in which the nodes 100a and 100c (nodes connected to the applications 200a and 200c) have these functions will be described. Specifically, an example of the following network configuration shown in FIG. 2 will be described.
The node 100a and the node 100b are connected by a link 300a that is a cryptographic communication network, and the node 100b and the node 100c are connected by a link 300b that is a cryptographic communication network.
The application 200a performs encrypted communication with the application 200c.
The application 200a acquires an application key from the node 100a for encrypted communication.
The application 200c acquires an application key from the node 100c for encrypted communication.

  FIG. 3 is a block diagram illustrating an example of the configuration of the node 100. As illustrated in FIG. 3, the node 100 includes a communication control unit 110, a management control unit 120, an access control unit 130, and a key storage unit 141.

  The key storage unit 141 stores an encryption key. The encryption key may be any encryption key including, for example, the link key and application key shown in FIG. The key storage unit 141 can be configured by any commonly used storage medium such as an HDD (Hard Disk Drive), an optical disk, a memory card, and a RAM (Random Access Memory).

  The communication control unit 110 controls communication with an external device such as the application 200. For example, the communication control unit 110 receives a message requesting access to the encryption key from the application 200. Further, the communication control unit 110 transmits the encryption key read from the key storage unit 141 to the application 200 in response to the message. Details of the function and configuration of the communication control unit 110 will be described later.

  The management control unit 120 controls encryption key management in accordance with the access request transmitted from the communication control unit 110. The management control unit 120 executes, for example, determination of encryption communication conditions with the application 200 and determination of necessary encryption key specifications as encryption key management. When the management control unit 120 accesses the encryption key stored in the key storage unit 141, the management control unit 120 transmits an access request to the access control unit 130.

  As described above, the management control unit 120 collects the access function to the key storage unit 141 in the access control unit 130. Thereby, for example, the access control unit 130 can easily detect abnormal access.

  The access control unit 130 controls access to the encryption key stored in the key storage unit 141 in response to the access request received via the management control unit 120.

  For encryption key management, it is preferable to use a database (key database) in order to execute management easily and efficiently. By distributing and managing the key database so that it is accessed from the access control unit 130, the key database can be designed to be difficult to leak when accessed from other than the management dedicated access function (access control unit 130). The distributed management of the encryption key also has an effect of protecting the encryption key from an attack that directly accesses the key storage unit 141 in a state where the power of the node 100 is shut off. A similar effect can be realized by encrypting the storage of the encryption key in the key storage unit 141.

  The communication control unit 110, the management control unit 120, and the access control unit 130, for example, may be realized by software by causing a processing device such as a CPU (Central Processing Unit) to execute a program, or an IC (Integrated Circuit) or other hardware, or a combination of software and hardware. The node 100 may be provided with a security chip, and the software and hardware may be validated by a trust chain from the security chip.

  Next, service use processing by the cryptographic communication system according to the first embodiment configured as described above will be described with reference to FIG. FIG. 4 is a sequence diagram illustrating an example of service use processing according to the first embodiment.

  First, the application 200 accesses the communication control unit 110 via a network and transmits a request for an encryption key generation service (step S101). The node 100 authenticates the validity of the request source application 200 (step S102). The node 100 transmits the authentication result to the application 200 (step S103). If authenticated, the application 200 and the node 100 discuss detailed specifications of the necessary encryption key (step S104), and start generating and providing the encryption key (step S105).

  When the cryptographic communication with the application 200 is completed, the application 200 requests termination of the cryptographic key generation service (step S106). In response to this request, the node 100 terminates the encryption key generation service and notifies the application 200 of the termination (step S107).

  As described above, a lot of information regarding the encryption key generation service is transmitted and received between the application 200 and the communication control unit 110. Part of the transmitted / received information is also transmitted to the management control unit 120 and the access control unit 130 in order to provide an encryption key corresponding to the request of the application 200. The provided encryption key is read from the key storage unit 141 by the access control unit 130, and transmitted and provided to the application 200 via the management control unit 120 and the communication control unit 110.

  In this way, transmission / reception of information occurs between the inside and outside of the node 100. For this reason, an external eavesdropper attempts to eavesdrop or leak the encryption key inside the node 100 from the outside through a route or path through which information is transmitted and received.

  Therefore, in this embodiment, in order to prevent such an attack or intrusion, the communication control unit 110 is designed to analyze the content of the message from the application 200.

  FIG. 5 is a block diagram illustrating an example of a detailed functional configuration of the communication control unit 110. As illustrated in FIG. 5, the communication control unit 110 includes a reception unit 111, an analysis unit 112, and a generation unit 113.

  The receiving unit 111 receives various types of information via a communication I / F (interface) (not shown in FIG. 5) connected to the application 200 or the like. For example, the receiving unit 111 receives a message requesting access to the encryption key from the application 200.

  FIG. 5 shows an example of the data structure of the message. In this example, the message includes a destination, authentication information, and a service message. The destination is, for example, identification information such as an IP address and a port number for designating use of the function of the management control unit 120. The authentication information is used, for example, to verify whether the received message is valid. A service message is an entity of a message including, for example, the contents of a service requested by a transmission source. Note that the data structure of the message is not limited to this.

  The receiving unit 111 sends a service message extracted from the received message to the analyzing unit 112.

  The analysis unit 112 parses the received message (service message) and analyzes whether or not it includes an access request for the encryption key stored in the key storage unit 141. For example, the analysis unit 112 analyzes the service message according to a predetermined syntax rule, and extracts an access request described in a format according to the syntax rule. The syntax rule may be any rule. For example, a rule determined in advance with a valid transmission partner (such as the application 200) can be used.

  When the received message includes an access request, the generation unit 113 generates request information for requesting access to the encryption key for which access is requested. This request information is information used inside the node 100. As shown in FIG. 5, the request information includes, for example, an internal destination and an internal message. The internal destination is a destination used inside the node 100. The internal message is a message including an access request analyzed by the analysis unit 112.

  Although the format of the internal message is arbitrary, for example, if the format is different from the service message received from the outside, unauthorized access to the encryption key from the outside can be reduced. If it is confirmed that the service message conforms to a predetermined syntax or content, the internal message is not constructed completely, but a necessary part of the message received from the application 200 is replaced with the internal message. It may be incorporated into a part and transmitted to the management control unit 120.

  The generation unit 113 transmits the generated request information (internal message) to the management control unit 120.

  By providing the analysis unit 112 and the generation unit 113, it is possible to prevent an external message or a code included in the message from being executed inside the communication control unit 110 of the system.

  In the configuration as described above, whenever the functions of the management control unit 120 and the access control unit 130 are updated, the communication control unit 110 needs to be updated so that an internal message can be transmitted and received in accordance with the update. . On the other hand, if the communication control unit 110 is updated, the update on the application 200 side can be made unnecessary. That is, it is possible to reduce the troubles such as modification on the application 200 side by updating the internal function of the node 100.

  Next, a key access process performed by the node 100 according to the first embodiment configured as described above will be described with reference to FIG. FIG. 6 is a flowchart illustrating an example of the key access process in the first embodiment.

  First, the reception unit 111 receives a message transmitted from the application 200 or the like via a communication interface (step S201). The receiving unit 111 extracts a service message from the received message (step S202). The receiving unit 111 may be configured to authenticate the message using authentication information included in the received message.

  The analysis unit 112 parses the service message (step S203). The analysis unit 112 determines whether or not the service message includes an access request for the encryption key (step S204). When the access request is included (step S204: Yes), the generation unit 113 generates request information (internal message) for requesting access to the encryption key for which access is requested (step S205). The generation unit 113 transmits the generated request information to the management control unit 120. Since the request information is key access processing, the management control unit 120 further transmits the request information to the access control unit 130. The access control unit 130 accesses the encryption key stored in the key storage unit 141 according to the request information (step S206).

  If the access request is not included (step S204: No), the key access process is terminated.

  Thus, the key storage unit 141 cannot be accessed unless it is analyzed in step S203 and step S204 that the access request is a correct access request according to the syntax rules. That is, even when connected to an existing communication system, the encryption key cannot be directly accessed from this communication system. Thereby, the security of the encryption key generated in the node 100 and the stored encryption key can be ensured.

(Modification 1)
Before a message transmitted from the outside enters the communication control unit 110, a firewall function may be provided to block an irrelevant message. FIG. 7 is a block diagram illustrating an example of the configuration of the node 100-2 according to the first modification configured as described above. As illustrated in FIG. 7, the node 100-2 includes a communication control unit 110, a management control unit 120, an access control unit 130, a key storage unit 141, and a firewall 150-2.

  The firewall 150-2 executes a firewall function that allows only legitimate messages to pass. For example, the firewall 150-2 has a function of judging the content of a message and allowing only the message of a customer who is providing the service to pass through. Further, the firewall 150-2 may be configured to determine a message transmission / reception phase and pass only a message having a correct phase. The firewall 150-2 may be provided with a function of periodically updating the attack message pattern and the like so as not to pass a message conforming to this pattern. Thereby, the defense against the latest attack is realized and the safety is further improved.

(Modification 2)
By the way, in an encryption key generation service, what is important for an attack from the outside such as a cyber attack is not to leak an encryption key, particularly an encryption key provided to a user. For that purpose, it is important to have a defense function against an outgoing message as well as a defense against an external message. In particular, the encryption key is information that cannot be changed or converted on the way and is transmitted from the key storage unit 141 to the application 200. For this reason, it is important for the encryption key generation service not to leak information regarding the confirmation of the transmission partner and the internal handling of the encryption key to the outside.

  The second modification further includes a verification function when transmitting a message to the outside. FIG. 8 is a block diagram illustrating an example of the configuration of the node 100-3 according to the second modification. As illustrated in FIG. 8, the node 100-3 includes a communication control unit 110-3, a management control unit 120-3, an access control unit 130, a key storage unit 141, and an identification information storage unit 142. .

  In addition to the function of the communication control unit 110 of the first embodiment, the communication control unit 110-3 further includes the following functions.

  When transmitting the provided encryption key to the application 200, the communication control unit 110-3 verifies whether or not it is going to be transmitted to the valid application 200 corresponding to the encryption key. For example, when the communication control unit 110-3 takes out the encryption key from the internal message and converts it into an external message, the communication control unit 110-3 checks whether the destination and the combination of the destination and the encryption key are correct. Specifically, the communication control unit 110-3 verifies that the ID associated with the encryption key and the ID (such as an application ID) associated with the destination are a correct combination.

  Further, when supporting a plurality of communication channels, the communication control unit 110-3 confirms whether a message is passed to the correct communication channel interface when sending a message to the outside.

  The communication control unit 110-3 creates a unique ID (request ID) in the node 100-3 for each requested encryption key generation service, and processes the delivery of the encryption key in the node 100-3 with the request ID May be. The identification information storage unit 142 stores identification information (application ID) for identifying the application 200 that has requested the encryption key generation service in association with the request ID. For example, the communication control unit 110-3 acquires a request ID corresponding to the application ID included in the service message from the identification information storage unit 142. And the communication control part 110-3 produces | generates the request information containing acquired request ID and the encryption communication conditions contained in a service message, and transmits to the management control part 120-3.

  The management control unit 120-3 controls encryption key management according to such request information.

  With such a configuration, it becomes more difficult to obtain information about the encryption key received by the specific application 200 from the outside. This is because the encryption key related to the target application 200 cannot be designated in advance when attacking the node 100-3 from the outside.

  Further, the access control unit 130 or the management control unit 120-3 may output the same encryption key multiple times, output the same encryption key in association with different request IDs, or receive the same encryption key. The output to a different communication partner may be monitored. As a result, the transmission of the encryption key is stopped at the time of abnormality, and leakage of the encryption key can be prevented.

  Next, a configuration example when the communication control unit 110, the management control unit 120, and the access control unit 130 are realized by software will be described. FIG. 9 is a diagram illustrating an example of a hardware configuration and a software configuration included in the node 100 configured as described above.

  The node 100 includes system hardware 330, a communication I / F 340, and a storage 350 as main hardware configurations. The node 100 includes a virtual machine OS (operating system) 320, OSs 310a and 310b, a communication control unit 110, a management control unit 120, and an access control unit 130 as main software configurations.

  The system hardware 330 includes a CPU 331, a ROM 332, a RAM 333, and a security chip 334.

  The communication I / F 340 is an interface that communicates by connecting to a network. The storage 350 is a storage device such as an HDD (Hard Disk Drive). For example, the key storage unit 141 corresponds to the storage 350.

  The virtual machine OS 320 is software that virtualizes a computer and makes it possible to execute a plurality of OSs in parallel. The OSs 310 a and 310 b are OSs executed on the virtual machine OS 320.

  As shown in FIG. 9, the communication control unit 110, the internal management control unit 120, the access control unit 130, and the like are executed on different OSs (OSs 310a and 310b). As a result, resistance against attacks using memory overflow can be improved.

  Further, each OS (OS 310a, 310b) and software (communication control unit 110, management control unit 120, and access control unit 130) operating on the OS are protected by a security chip 334. Furthermore, it may be configured to improve safety by performing mutual authentication between modules (between the communication control unit 110, the management control unit 120, and the access control unit 130).

  As described above, according to the present embodiment, the management control unit 120 or the like can be configured not to be directly accessible from the outside. In writing and reading of the encryption key, the encryption key data itself must be handled transparently together with information (key ID) for identifying the encryption key. Therefore, it is important that the management control unit 120 and further the access control unit 130 are not affected by a malicious person.

(Modification 3)
In Modification 3, an example in which encryption key management is multilayered will be described. FIG. 10 is a conceptual diagram showing an example of management in multiple layers in two layers of link key and application key. FIG. 10 schematically shows that a link key, which is a higher class key, is managed in association with a plurality of application keys, which are lower class keys.

  FIG. 11 is a diagram showing an example of management information used for realizing the multi-layering as shown in FIG. The management information includes a key ID, a key virtual class, a higher class ID, and key information. The key information is encryption key data corresponding to the key ID.

  The key virtual class represents a hierarchy (class) to which the multilayered encryption key belongs. In the example of FIG. 10, either a link class or a node class is set as the key virtual class.

  The upper class ID represents the key ID of the upper class encryption key associated with the encryption key set in the key virtual class. FIG. 11 shows an example in which the encryption key with key ID = 0002 is an application key, and the encryption key of the upper class is a link key with key ID = 0001.

  For example, the access control unit 130 accesses the encryption key stored in the key storage unit 141 using such management information. The encryption key may be managed using the attribute of the encryption key. The attribute is, for example, information indicating whether the encryption key is a “link key” or an “application key”.

  You may comprise so that each management of the encryption key of each hierarchy may be modularized. FIG. 12 is a block diagram illustrating a configuration example of the node 100 configured as described above. In FIG. 12, only the management control unit 120, the access control units 130a and 130b, and the key storage units 141a and 141b are illustrated, and other configuration units are omitted.

  The configuration example shown in FIG. 12 includes two access control units 130a and 130b and two key storage units 141a and 141b. The key storage units 141a and 141b store application keys and link keys, respectively. The key storage units 141a and 141b may be configured as different storage areas of the physically same storage medium, or may be configured of physically different storage media.

  The access control units 130a and 130b control access to the key storage units 141a and 141b, respectively.

  With such a configuration, the degree of isolation from the outside can be further improved for encryption keys (link key, application key, etc.) other than the encryption key (application key, etc.) provided directly to the application 200, for example. That is, for example, it is possible to make it difficult to access the valuable quantum key delivered by QKD from the outside.

  Note that a plurality of management control units 120 may be provided corresponding to each hierarchy of encryption keys. That is, the encryption key generation and management processing for each layer may be configured to be multilayered. Thereby, the safety | security of the specific function of an encryption key generation service can be improved more.

  As described above, according to the first embodiment, it is possible to make an encryption key eavesdropping and copying attacks from the outside through a communication interface for providing an encryption key difficult, and to provide an encryption key safely.

(Second Embodiment)
Depending on the configuration of the encryption key generation service, the encryption key may be generated at a plurality of locations required by the application 200. In order to share the encryption key, for example, a function (management control unit) that manages the encryption key may have a communication channel for a communication partner other than the application 200. In this case, this communication channel can also be an attack or intrusion route from the outside.

  In the second embodiment, an example in which a plurality of communication channels (communication I / F) are provided will be described. FIG. 13 is a block diagram illustrating an example of a configuration of the node 100-4 according to the second embodiment. As illustrated in FIG. 13, the node 100-4 includes a communication control unit 110, a management control unit 120-4, an access control unit 130, a key storage unit 141, and a communication control unit 160-4.

  The second embodiment is different from the first embodiment in that the function of the management control unit 120-4 and the communication control unit 160-4 are added. Other configurations and functions are the same as those in FIG. 3 which is a block diagram of the node 100 according to the first embodiment, and thus the same reference numerals are given and description thereof is omitted here.

  The management control unit 120-4 not only communicates with the application 200 (not shown in FIG. 13), but also communicates (I / F) for exchanging and synchronizing the generated encryption key (for example, link key) ( It communicates with the outside via (not shown in FIG. 13).

  The communication control unit 160-4 controls communication via an encryption key exchange and synchronization communication I / F. The communication control unit 160-4 has the same function as the communication control unit 110. Thereby, it is difficult to attack from the outside via the communication I / F against the communication partner other than the application 200, and the safety can be improved.

  FIG. 13 illustrates an example in which the communication control unit 160-4 is operated on an OS 310c different from the OS 310a and the OS 310b. With such a configuration, it is possible to further improve resistance to attacks using memory overflow.

(Third embodiment)
The same consideration is necessary for the operation management function. The operation management function is necessary for stable and steady operation of the node. The operation management function includes a communication function for centralized management, and the function is expanded via the network. Therefore, it is also necessary to prevent attacks on the encryption key via the communication channel used by the operation management function.

  In the third embodiment, an example provided with an operation management function having a corresponding communication channel (communication I / F) will be described. FIG. 14 is a block diagram illustrating an example of a configuration of the node 100-5 according to the third embodiment. As illustrated in FIG. 14, the node 100-5 includes a communication control unit 110, a management control unit 120, an access control unit 130-5, a key storage unit 141, an operation control unit 170-5, and an operation information storage. Part 143.

  The third embodiment is different from the first embodiment in that the function of the access control unit 130-5 and the operation control unit 170-5 and the operation information storage unit 143 are added. Other configurations and functions are the same as those in FIG. 3 which is a block diagram of the node 100 according to the first embodiment, and thus the same reference numerals are given and description thereof is omitted here.

  The operation information storage unit 143 stores various information used for operation management.

  The operation control unit 170-5 receives an operation management request from the management server 400, and controls various operation management functions in response to the request. The management server 400 is a server that remotely performs an operation management function. The operation control unit 170-5 communicates with the management server 400 via a communication I / F (not shown) different from the communication I / F connected to the application 200.

  The operation control unit 170-5 may have the same function as the communication control unit 110. For example, the operation control unit 170-5 interprets an external command and creates a necessary response. The command includes a command (write command) for writing (registration, working). The operation control unit 170-5 confirms that the received command has a predefined content. Thereby, abnormal access can be prevented from occurring.

  The access control unit 130-5 further includes a function of denying access to the encryption key requested from the operation control unit 170-5. For example, the access control unit 130-5 is designed not to return key information in response to a message from the operation control unit 170-5. Accordingly, it is possible to suppress a risk that key information is leaked by an attack targeting the operation control unit 170-5.

(Fourth embodiment)
In the fourth embodiment, as a derivation of a node that realizes the encryption key generation service, it is configured as a relay node that does not accept access from the application 200, manages encryption key exchange (synchronization), and relays encryption keys An example will be described. The relay node is used when there is a limit on a communicable distance in encryption communication for exchanging and synchronizing encryption keys. Such a relay node is useful because there is an advantage of improving the design flexibility of the cryptographic communication system with a simple node configuration. For example, by using a relay node, it is possible to increase the distance of encrypted communication even when there is a limit on the distance, and as a result, it is possible to increase the speed of encrypted communication.

  FIG. 15 is a block diagram illustrating an example of a configuration of the node 100-6 according to the fourth embodiment. As illustrated in FIG. 15, the node 100-6 includes communication control units 160-4a and 160-4b, management control units 120a and 120b, an access control unit 130, a key storage unit 141, and an operation control unit 170-. 5 and an operation information storage unit 143.

  In the fourth embodiment, the communication control unit 110 is deleted, a plurality of communication control units 160-4a and 160-4b, and a plurality of management control units 120a and 120b are included in the third embodiment. Is different. Other configurations and functions are the same as those in FIG. 14 which is a block diagram of the node 100-5 according to the third embodiment, and thus are denoted by the same reference numerals and description thereof is omitted here.

  Each of the communication control units 160-4a and 160-4b controls communication via a communication I / F (not shown) connected to a communication partner for exchanging encryption keys. The communication control units 160-4a and 160-4b have the same functions as the communication control unit 160-4 in FIG. 13 (that is, the communication control unit 110 in FIG. 3). This makes it difficult to attack from the outside and improves safety.

  The node 100-6 of this embodiment is configured as a relay node that relays (transfers) the encryption key. Therefore, for example, the communication control unit 160-4a receives a message requesting to relay an encryption key transmitted from a certain external device (first device) to another external device (second device). The communication control unit 160-4a stores the encryption key requested to be relayed in the key storage unit 141 via the access control unit 130.

  The communication control unit 160-4a requests the communication control unit 160-4b to transfer the stored encryption key to the second device. In response to this request, the communication control unit 160-4b reads the encryption key from the key storage unit 141 and transmits it to the second device.

  Note that one communication control unit 160-4 may be configured to realize the functions of the communication control units 160-4a and 160-4b. Similarly, one management control unit 120 may be configured to realize the functions of the management control units 120a and 120b.

  Further, in the present embodiment, an example of modification based on the third embodiment has been described. However, a relay node that combines one or more functions of the other embodiments and modifications described above may be used.

  By the way, the encryption key generation service as described above may be additionally provided as a means for improving the security of existing applications that perform encrypted communication.

  As a providing method, a method of providing a module to be added to an existing application in the form of an application built-in library or an external filter can be considered. In this case, it is necessary to design a mutual authentication method in communication between the providing module and the communication control unit in consideration of safety. This is because the provision module may be used by a malicious person to facilitate spoofing of the communication control unit and man-in-the-middle wiretapping between the application and the communication control unit.

  Basically, a means for reliably sharing information for mutual authentication with an application may be prepared. If an existing application has a sufficiently reliable authentication system, it can be used. It is necessary to select a utilization method according to the form of the provided module.

  As described above, according to the first to fourth embodiments, since an encryption key cannot be directly accessed from an external system, an encryption key generation service that can provide a more advanced encryption key can be used safely.

  A program executed by the communication device according to the first to fourth embodiments is provided by being incorporated in advance in a ROM or the like.

  A program executed by the communication device according to the first to fourth embodiments is an installable or executable file, which is a CD-ROM (Compact Disk Read Only Memory), a flexible disk (FD), a CD- It may be configured to be recorded on a computer-readable recording medium such as R (Compact Disk Recordable), DVD (Digital Versatile Disk) and the like and provided as a computer program product.

  Furthermore, the program executed by the communication device according to the first to fourth embodiments may be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network. Good. The program executed by the communication device according to the first to fourth embodiments may be provided or distributed via a network such as the Internet.

  The program executed by the communication device according to the first to fourth embodiments can cause a computer to function as each unit of the communication device described above. In this computer, the CPU can read a program from a computer-readable storage medium onto a main storage device and execute the program.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

100 node 110 communication control unit 111 reception unit 112 analysis unit 113 generation unit 120 management control unit 130 access control unit 141 key storage unit 142 identification information storage unit 143 operation information storage unit 150 firewall 160 communication control unit 170 operation control unit 200 application

Claims (7)

A first interface for receiving messages from the application;
A second interface for sharing the encryption key;
A first key storage unit for storing a first encryption key shared via the second interface;
A second key storage unit for storing a second encryption key shared via the second interface;
A first access control unit for controlling access to the first encryption key;
A second access control unit for controlling access to the second encryption key;
An analysis unit that analyzes whether the message received from the first interface includes a first access request for the first encryption key or the second encryption key;
Information requesting access to the first encryption key or the second encryption key requested by the first access request when the message includes the first access request, the first access request; Generating a second access request in a different format, and transmitting the generated second access request to the first access control unit,
The first access control unit controls access to the first encryption key when the generated second access request is an access request for the first encryption key, and the second access request is the first access request. If the access request is for two encryption keys, the second access request is transmitted to the second access control unit,
The second access control unit controls access to the second encryption key based on the second access request received from the first access control unit;
Communication device. The message includes first identification information for identifying an application that uses the first encryption key or the second encryption key;
An identification information storage unit for storing the first identification information and the second identification information in association with each other;
The generation unit generates the second access request in which the second identification information corresponding to the first identification information included in the received message is associated when the message includes the first access request. To
The communication apparatus according to claim 1. Executing at least one of the analysis unit and the generation unit, and the first access control unit and the second access control unit on different operating systems;
The communication apparatus according to claim 1. An operation control unit that receives an operation management request for the communication device and controls operation management of the communication device according to the received request,
The first access control unit denies access to the first encryption key requested by the operation control unit;
The second access control unit denies access to the second encryption key requested by the operation control unit;
The communication apparatus according to claim 1. The first key storage unit stores the first encryption key transmitted from the first device,
The first interface receives the message requesting to relay the first encryption key transmitted from the first device to a second device;
The generating unit generates the second access request of the first encryption key requested to be relayed by the first access request when the message includes the first access request;
The first access control unit reads the first encryption key from the key storage unit based on the second access request.
The communication apparatus according to claim 1. The second key storage unit stores the second encryption key transmitted from the first device,
The first interface receives the message requesting to relay the second encryption key transmitted from the first device to the second device;
The generation unit generates the second access request of the second encryption key requested to be relayed by the first access request when the message includes the first access request;
The second access control unit reads the second encryption key from the key storage unit based on the second access request.
The communication apparatus according to claim 1. A first interface for receiving a message from an application; a second interface for sharing an encryption key; a first key storage unit for storing a first encryption key shared via the second interface; A second key storage unit that stores a second encryption key shared via the second interface; a first access control unit that controls access to the first encryption key; and controls access to the second encryption key A key management method executed by a communication device comprising: a second access control unit that includes:
An analysis step of analyzing whether the message received from the first interface includes a first access request for the first encryption key or the second encryption key;
Information requesting access to the first encryption key or the second encryption key requested by the first access request when the message includes the first access request, the first access request; Generating a second access request of a different format, and transmitting the generated second access request to the first access control unit,
The first access control unit controls access to the first encryption key when the generated second access request is an access request for the first encryption key, and the second access request is the first access request. If the access request is for two encryption keys, the second access request is transmitted to the second access control unit,
The second access control unit controls access to the second encryption key based on the second access request received from the first access control unit;
Key management method.

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