System and method

Abstract

This system performs an exchange transaction between a first electronic value owned by a first device and a second electronic value owned by a second device. The system is provided with: a selection unit that selects a mediation device by using the first device and the second device; and a transaction instruction unit that is provided in the mediation device to give an instruction to carry out or stop the exchange transaction to the first device or the second device.

Description

System and method

[0001] The present disclosure relates to a system and method for conducting an exchange transaction of electronic value.

[0002] There is a system for conducting an exchange transaction of electronic value between a first device and a second device. In such a system, for example, the exchange transaction of electronic value may be interrupted due to a communication error or the like. For this reason, for example, in Patent Documents 1 and 2, it is described that when the exchange transaction between the first device and the second device is interrupted, a predetermined specific mediation device performs the completion or cancellation of the exchange transaction.

[0003] Japanese Unexamined Patent Application Publication No. 2004-341643, Japanese Unexamined Patent Application Publication No. 2008-15783

[0004] The mediation device described in the above-mentioned patent documents is predetermined. For this reason, for example, when a plurality of exchange transaction errors occur simultaneously, requests for mediation are concentrated on the predetermined mediation device. As a result, it is conceivable that the mediation device cannot appropriately perform the mediation process.

[0005] Therefore, the present disclosure will describe a system and method capable of suppressing the concentration of requests for mediation processing on a specific mediation device.

[0006] In the present disclosure, in a system for conducting an exchange transaction between a first electronic value owned by a first device and a second electronic value owned by a second device, a selection unit that selects a mediation device by the first device and the second device, and provided in the mediation device, when the exchange transaction between the first device and the second device is interrupted, a transaction instruction unit that instructs the first device or the second device to complete or cancel the exchange transaction.

[0007] According to the present disclosure, it is possible to suppress the concentration of requests for mediation processing on a specific mediation device.

[0008] Figure 1 is a block diagram showing the overall configuration of the electronic value exchange system. Figure 2 is a diagram showing the processing sequence of the main protocol for electronic value exchange transactions. Figure 3 is a diagram showing the processing sequence of the Solve protocol. Figure 4 is a diagram showing the processing sequence of the Abort protocol. Figure 5 is a diagram showing an example of the hardware configuration of the first user device, the second user device, and the arbitration device.

[0009] Embodiments of this disclosure will be described with reference to the attached drawings. Where possible, the same parts will be denoted by the same reference numerals, and redundant descriptions will be omitted. In the following description, "First" and "Second" in the names are used to identify the objects to which they are attached, and the magnitude of the numbers does not indicate order or anything else.

[0010] Figure 1 is a block diagram showing the overall configuration of the electronic value exchange system. As shown in Figure 1, the electronic value exchange system (system) 100 executes an electronic value exchange protocol for the fair exchange of electronic value. The electronic value exchange system 100 comprises a first user device (first device) 1A, a second user device (second device) 1B, and an arbitration device 2. The first user device 1A and the second user device 1B conduct exchange transactions to exchange electronic value with each other. In this case, the electronic value exchange system 100 conducts an exchange transaction to exchange electronic value V1 (first electronic value) owned by the first user device 1A with electronic value V2 (second electronic value) owned by the second user device 1B.

[0011] For example, the first user device 1A and the second user device 1B may be smartphones. In this case, for example, an exchange transaction may be performed in which points, which are electronic value V1 owned by the first user device 1A, are exchanged for coupons, which are electronic value V2 owned by the second user device 1B. In this case, the processing related to the exchange transaction of electronic value may be executed, for example, in the environment of the TEE [Trusted Execution Environment] of the first user device 1A and the second user device 1B, which are smartphones.

[0012] Furthermore, as an example, the first user device 1A and the second user device 1B may be IC cards [Integrated Circuit Cards]. In this case, as an example, an exchange transaction may be performed in which a ticket representing electronic value V1 owned by the first user device 1A is exchanged for a ticket representing electronic value V2 owned by the second user device 1B. In this case, the processing related to the exchange transaction of electronic value is performed within the first user device 1A and the second user device 1B, which are IC cards.

[0013] However, the first user device 1A and the second user device 1B are not limited to being smartphones or IC cards. The first user device 1A and the second user device 1B may be composed of devices other than those described above. The method of transmitting and receiving various types of data transmitted and received between the first user device 1A and the second user device 1B for the exchange of electronic value is not limited. The electronic value exchanged between the first user device 1A and the second user device 1B is not limited to the points, coupons, and tickets described above. Other types of electronic value may be used as the exchange target, as long as they are exchangeable between the first user device 1A and the second user device 1B.

[0014] The mediation device 2 is selected by the first user device 1A and the second user device 1B. If the exchange transaction of electronic value between the first user device 1A and the second user device 1B is interrupted, the mediation device 2 instructs the first user device 1A and the second user device 1B to complete or cancel the exchange transaction. An interruption of the exchange transaction of electronic value may occur, for example, when communication for the exchange of electronic value between the first user device 1A and the second user device 1B is interrupted, or when an unexpected error occurs in the first user device 1A or the second user device 1B.

[0015] More specifically, the first user device 1A functionally comprises a first value management unit 11A, a first storage unit 12A, a first selection unit 13A, a first verification unit 14A, and a first request unit 15A. The first value management unit 11A performs the addition and deletion of electronic values ​​to and from the first effective value set possessed by the first user device 1A. The first effective value set is a set for identifying effective electronic values. By being included in the first effective value set, an electronic value is considered to be an effective value. In this embodiment, the first effective value set is stored, for example, in the first storage unit 12A. Furthermore, electronic value is electronic information that represents the electronic value (for example, information that defines the content of the electronic value, and the issuer's fingerprint, etc.). Note that a fingerprint is, for example, a hashed value of a public key.

[0016] The first storage unit 12A stores the first effective value set described above, and various information necessary for the exchange transaction of electronic value. The first selection unit 13A, together with the second selection unit 13B of the second user device 1B, selects the mediation device 2. The first verification unit 14A performs various verification processes, such as verification of the second user device 1B and the mediation device 2. If the exchange transaction of electronic value with the second user device 1B is interrupted, the first request unit 15A requests the transaction instruction unit 22 of the mediation device 2 to mediate the exchange transaction.

[0017] Functionally, the second user device 1B is similar to the first user device 1A in that it includes a second value management unit 11B, a second storage unit 12B, a second selection unit 13B, a second verification unit 14B, and a second request unit 15B. The second value management unit 11B performs the addition and deletion of electronic value to the second effective value set possessed by the second user device 1B. The second effective value set is a set for identifying effective electronic value, similar to the first effective value set. By including electronic value in the second effective value set, the electronic value is considered effective value. In this embodiment, the second effective value set is stored, for example, in the second storage unit 12B.

[0018] The second storage unit 12B stores the second effective value set described above, and various information necessary for the exchange transaction of electronic value. The second selection unit 13B, together with the first selection unit 13A of the first user device 1A, selects the mediation device 2. The second verification unit 14B performs various verification processes, such as verification of the first user device 1A and the mediation device 2. If the exchange transaction of electronic value with the first user device 1A is interrupted, the second request unit 15B requests the transaction instruction unit 22 of the mediation device 2 to mediate the exchange transaction.

[0019] For example, there is a case where electronic value V1 owned by the first user device 1A is to be exchanged with electronic value V2 owned by the second user device 1B. In this case, for example, the first value management unit 11A of the first user device 1A removes electronic value V1 from the first effective value set, and the second value management unit 11B of the second user device 1B adds electronic value V1 to the second effective value set. Furthermore, the second value management unit 11B of the second user device 1B removes electronic value V2 from the second effective value set, and the first value management unit 11A of the first user device 1A adds electronic value V2 to the first effective value set. By performing these processes, the exchange transaction between electronic value V1 and electronic value V2 is completed between the first user device 1A and the second user device 1B.

[0020] Functionally, the mediation device 2 comprises a verification unit 21, a transaction instruction unit 22, and a storage unit 23. The verification unit 21 verifies whether it (the mediation device 2) is the mediation device selected by the first selection unit 13A of the first user device 1A and the second selection unit 13B of the second user device 1B. The transaction instruction unit 22 instructs the first user device 1A or the second user device 1B to complete or cancel the exchange transaction if the exchange transaction of electronic value between the first user device 1A and the second user device 1B is interrupted. The transaction instruction unit 22 instructs the completion or cancellation of the exchange transaction based on a request for mediation of the exchange transaction from the first user device 1A or the second user device 1B. The storage unit 23 stores information such as information necessary to complete or cancel the exchange transaction of electronic value between the first user device 1A and the second user device 1B.

[0021] Next, we will explain the processing sequence of the main protocol for an electronic value exchange transaction, using the example of exchanging electronic value V1 owned by the first user device 1A with electronic value V2 owned by the second user device 1B. Figure 2 is a diagram showing the processing sequence of the main protocol for an electronic value exchange transaction. Here, it is assumed that the first user device 1A and the second user device 1B have mutually agreed to conduct an exchange transaction between electronic value V1 and electronic value V2. Furthermore, the processing sequence of this main protocol for an electronic value exchange transaction is initiated when the first user device 1A requests the second user device 1B to conduct an electronic value exchange transaction.

[0022] As shown in Figure 2, when an exchange transaction is initiated, as process a1 of step S11, the first verification unit 14A of the first user device 1A transmits the first electronic value exchange format, the first trust information, and the first guarantee certificate, which are used for various verification processes, to the second user device 1B. The first selection unit 13A also transmits the first mediation device list, which is used for selecting the mediation device 2, to the second user device 1B. The first electronic value exchange format, the first trust information, the first guarantee certificate, and the first mediation device list are, for example, pre-set and stored in the first storage unit 12A.

[0023] The first electronic value exchange format is the format used when transferring electronic value V1 (for example, the sender's electronic signature and the sender's public key). The first trust information is the information used by the issuer K1 of electronic value V1 to designate a trustworthy guarantor G1 (for example, a set of fingerprints of guarantor G1 designated by issuer K1, issuer K1's electronic signature on guarantor G1's fingerprint, and issuer K1's public key). The first guarantee is a guarantee in which guarantor G1 guarantees the security of the first user device 1A (for example, guarantor G1's electronic signature on the device's public key and guarantor G1's public key), and a guarantee in which guarantor G1 guarantees the security of the mediation device (mediation device included in the first mediation device list). The first mediation device list (mediation device information) is a list of mediation devices trusted by the first user device 1A (the user of the first user device 1A) (for example, the fingerprints of the mediation devices). This list includes one or more trusted mediation agencies. The first mediation agency list contains information to identify the trusted mediation agency.

[0024] When the second user device 1B obtains information such as the first electronic value exchange format from the first user device 1A, it performs processes b1 to b6 of step S12. Specifically, as process b1, the second verification unit 14B verifies the first electronic value exchange format. In process b1, the second verification unit 14B verifies whether or not the first electronic value exchange format was issued by issuer K1 of the electronic value V1. The second verification unit 14B can perform this verification based on the information contained in the first electronic value exchange format.

[0025] As process b2, the second verification unit 14B performs verification regarding the guarantee of the first user device 1A. In process b2, the second verification unit 14B verifies whether the guarantor G1, who is trusted by the issuer K1 of the electronic value V1, guarantees the first user device 1A. The second verification unit 14B can perform this verification based on the first trust information and the first guarantee certificate obtained from the first user device 1A. If this verification is successful, it can be said that the second user device 1B has the tamper resistance that the issuer K1 of the electronic value V1 trusts.

[0026] As process b3, the second selection unit 13B selects a mediator based on the first mediator list obtained from the first user device 1A. Here, the second selection unit 13B compares the first mediator list obtained from the first user device 1A with the second mediator list held by the second user device 1B. The second mediator list, like the first mediator list, is a list of mediators trusted by the second user device 1B (the user of the second user device 1B) (for example, a fingerprint of the mediator). The second mediator list is, for example, pre-configured and stored in the second storage unit 12B.

[0027] The second selection unit 13B selects a mediating device that matches in the two lists as mediating device 2, which will mediate when an electronic value exchange transaction is interrupted. If there are multiple mediating devices that match in the two lists, the second selection unit 13B may, for example, randomly select one mediating device as mediating device 2. The first selection unit 13A of the first user device 1A and the second selection unit 13B of the second user device 1B function as selection units that select mediating device 2 by the first user device 1A and the second user device 1B. Thus, in the process a1 (selection step) of transmitting the first mediating device list, and the process b3 (selection step) of selecting a mediating device based on the first mediating device list and the second mediating device list, mediating device 2 is selected by the first user device 1A and the second user device 1B.

[0028] As process b4, the second verification unit 14B generates a random number n. The second verification unit 14B adds the generated random number n to the second set of valid sessions. The second set of valid sessions is managed by the second user device 1B. In this embodiment, the second set of valid sessions is stored, for example, in the second storage unit 12B. The second set of valid sessions is a collection for storing the session numbers of valid sessions (sessions related to exchange transactions). The session number is used when requesting the mediation device 2 to complete or cancel an exchange transaction if an exchange transaction of electronic value is interrupted.

[0029] As process b5, the second value management unit 11B deletes the electronic value V2 from the second effective value set. As process b6, the second verification unit 14B transmits the second electronic value exchange format, second trust information, second guarantee certificate, and the hash value of the random number n, which are used for various verification processes, to the first user device 1A. The second selection unit 13B also transmits the selected mediation device 2 (information for identifying the selected mediation device 2) to the first user device 1A. The second electronic value exchange format, second trust information, and second guarantee certificate are, for example, pre-set and stored in the second storage unit 12B. The hash value of the random number n is, for example, the value generated by applying a hash function to the random number n generated in process b4.

[0030] The second electronic value exchange format is the format used when transferring electronic value V2, similar to the first electronic value exchange format. The second trust information is the information used by issuer K2 of electronic value V2 to designate a trustworthy guarantor G2, similar to the first trust information. The second guarantee certificate is the same as the first guarantee certificate, a guarantee certificate in which guarantor G2 guarantees the security of the second user device 1B, and a guarantee certificate in which guarantor G2 guarantees the security of the mediation device (mediation device included in the second mediation device list).

[0031] Furthermore, if verification of processes b1 and b2 in step S12 is not possible, or if an arbitration device cannot be selected in process b3, the second user device 1B will terminate the process in step S12. As a result, the exchange transaction is terminated. At this point, the electronic value V1 has not been deleted on the first user device 1A side, and the electronic value V2 has not been deleted on the second user device 1B side. Therefore, even if the exchange transaction of electronic value is terminated at this stage, the fairness of the transaction is guaranteed.

[0032] Furthermore, it is preferable that process b6 is performed after processes b1 to b5 are completed. Also, it is preferable that process b5 is performed at least after processes b1 to b3 are completed. Processes b1 to b4 are not limited to being performed in the order of processes b1, b2, b3, and b4 described above.

[0033] When the first user device 1A obtains information such as the second electronic value exchange format from the second user device 1B, it performs processes a2 to a7 in step S13. Specifically, in process a2, the first verification unit 14A verifies the second electronic value exchange format. In process b1, the second verification unit 14B verifies whether or not the second electronic value exchange format was issued by issuer K2 of the electronic value V2. The first verification unit 14A can perform this verification based on the information contained in the second electronic value exchange format.

[0034] As process a3, the first verification unit 14A performs verification regarding the guarantee of the second user device 1B. In process a3, the first verification unit 14A verifies whether the guarantor G2, who is trusted by the issuer K2 of the electronic value V2, guarantees the second user device 1B. The first verification unit 14A can perform this verification based on the second trust information and the second guarantee certificate obtained from the second user device 1B. If this verification is successful, it can be said that the first user device 1A has the tamper resistance that the issuer K2 of the electronic value V2 trusts.

[0035] As process a4, the first selection unit 13A verifies the effectiveness of the arbitration device 2 selected by the second user device 1B. Here, the first selection unit 13A can verify the effectiveness of the selected arbitration device 2 by, for example, checking the list of first arbitration devices stored in the first storage unit 12A.

[0036] As process a5, the first verification unit 14A adds the hash value of the random number n obtained from the second user device 1B to the first valid session set. The first valid session set is managed in the first user device 1A, similar to the second valid session set. In this embodiment, the first valid session set is stored, for example, in the first storage unit 12A. The first valid session set is the same as the second valid session set described above.

[0037] As process a6, the first value management unit 11A deletes the electronic value V1 from the first effective value set. As process a7, the first verification unit 14A transmits the hash value of the random number n added to the first effective session set to the second user device 1B.

[0038] Furthermore, it is preferable that process a7 is performed after processes a2 to a6 are completed. Also, it is preferable that process a6 is performed at least after processes a2 to a4 are completed. Processes a2 to a5 are not limited to being performed in the order of processes a2, a3, a4, and a5 described above.

[0039] When the second user device 1B obtains the hash value of the random number n from the first user device 1A, it performs processes b7 to b10 of step S14. Specifically, as process b7, the second verification unit 14B verifies the validity of the hash value of the random number n obtained from the first user device 1A. Here, the second verification unit 14B applies a hash function to the random number n generated in process b4 of step S12, for example, to calculate the hash value of the random number n. Then, the second verification unit 14B can verify the validity by comparing the calculated hash value of the random number n with the hash value of the random number n obtained from the first user device 1A.

[0040] As process b8, the second verification unit 14B removes the random number n that was added to the second valid session set in process b4 of step S12 from the second valid session set. As process b9, the second value management unit 11B adds the electronic value V1 to the second valid value set. As process b10, the second verification unit 14B transmits the random number n generated in process b4 to the first user device 1A. This completes the electronic value exchange transaction in which the second user device 1B passes the electronic value V2 to the first user device 1A and obtains the electronic value V1 from the first user device 1A.

[0041] When the first user device 1A obtains a random number n from the second user device 1B, it performs processes a8 to a10 in step S15. Specifically, as process a8, the first verification unit 14A verifies the validity of the random number n obtained from the second user device 1B. Here, the first verification unit 14A generates a hash value of the random number n by, for example, applying a hash function to the random number n obtained from the second user device 1B. The first verification unit 14A can verify the validity by comparing the generated hash value of the random number n with the hash value of the random number n added to the first valid session set in process a5 of step S13.

[0042] In process a9, the first verification unit 14A deletes the hash value of the random number n added to the first valid session set in process a5 of step S13 from the first valid session set. As process a10, the first value management unit 11A adds the electronic value V2 to the first valid value set. As a result, in the first user device 1A, an exchange transaction of electronic values, where the first user device 1A transfers the electronic value V1 to the second user device 1B and acquires the electronic value V2 from the second user device 1B, is completed.

[0043] Here, if the exchange transaction of electronic values is interrupted after the completion of various processes in step S13, in the first user device 1A, since the electronic value V1 has been deleted, an unfair state occurs in the exchange transaction. Therefore, if the exchange transaction of electronic values is interrupted after the completion of various processes in step S13, the first user device 1A requests the arbitration device 2 selected by the second user device 1B to complete the exchange transaction (request for arbitration) in order to restore the fairness of the exchange transaction. By this request for completion, a Resolve protocol for restoring the fairness of the exchange transaction is started between the first user device 1A and the arbitration device 2.

[0044] Also, if the exchange transaction of electronic values is interrupted after the completion of various processes in step S12, in the second user device 1B, since the electronic value V2 has been deleted, an unfair state occurs in the exchange transaction. Therefore, if the exchange transaction of electronic values is interrupted after the completion of various processes in step S12, the second user device 1B requests the arbitration device 2 selected in process b3 of step S12 to cancel the exchange transaction (request for arbitration) in order to restore the fairness of the exchange transaction. By this request for cancellation, an Abort protocol for restoring the fairness of the exchange transaction is started between the second user device 1B and the arbitration device 2.

[0045] First, the processing sequence of the Resolve protocol in which the first user device 1A requests the mediation device 2 to complete an exchange transaction will be described. FIG. 3 is a diagram showing the processing sequence of the Resolve protocol. As shown in FIG. 3, as processing a11 in step S21, the first verification unit 14A transmits the hash value of the random number n used for verification processing and the like to the mediation device 2. Also, the first selection unit 13A transmits the mediation device 2 (information for specifying the selected mediation device 2) selected by the second selection unit 13B of the second user device 1B to the mediation device 2. Note that the hash value of this random number n is a value added to the first session set in processing a5 of step S13 shown in FIG. 2.

[0046] The first request unit 15A requests the transaction instruction unit 22 of the mediation device 2 to complete an exchange transaction of electronic value. That is, when the exchange transaction with the second user device 1B is interrupted in a state where the electronic value V1 has been deleted from the first valid value set by the first value management unit 11A, the first request unit 15A requests the transaction instruction unit 22 of the mediation device 2 to complete the exchange transaction.

[0047] When the mediation device 2 receives a request to complete an exchange transaction of electronic value from the first user device 1A, it performs processing b11 to b13 in step S22. Specifically, as processing b11, the verification unit 21 verifies the first user device 1A that has requested the completion of the exchange transaction. Here, the verification unit 21 verifies whether the request for completion has been transmitted from the first user device 1A. The verification unit 21 performs verification based on, for example, the electronic signature, public key, etc. of the first user device 1A transmitted from the first user device 1A together with the request for completion.

[0048] As processing b12, the verification unit 21 verifies whether the mediation device 2 selected by the first user device 1A and the second user device 1B is itself (the mediation device 2) based on the information for specifying the mediation device 2 acquired from the first user device 1A.

[0049] As process b13, the verification unit 21 verifies whether a hash value of random number n exists in the set of valid sessions (abort). The set of valid sessions (abort) is managed by the arbitration device 2. In this embodiment, the set of valid sessions (abort) is stored, for example, in the storage unit 23. The set of valid sessions (abort) is the same as the first set of valid sessions, etc. For example, process b13 is performed if the verification of processes b11 and b12 is successful.

[0050] Next, the arbitration device 2 performs the process in step S23. If, as a result of the verification of process b13, a hash value of random number n exists in the set of valid sessions (abort), then process b14 of step S23 is performed. In process b14 (transaction instruction step), the transaction instruction unit 22 instructs the first user device 1A to cancel the exchange transaction.

[0051] On the other hand, if the verification in process b13 shows that the hash value of random number n does not exist in the set of valid sessions (abort), then processes b15 and b16 in step S23 are performed. In process b15, the verification unit 21 adds the hash value of random number n to the set of valid sessions (resolve). The set of valid sessions (resolve) is the same as the set of valid sessions (abort). In process b16 (transaction instruction step), the transaction instruction unit 22 instructs the first user device 1A to complete the exchange transaction.

[0052] In this way, the verification unit 21 verifies whether the arbitration device 2 selected by the first selection unit 13A of the first user device 1A and the second selection unit 13B of the second user device 1B is itself (processing b12 of step S22). If it is itself (the arbitration device 2) that was selected as arbitration device 2, the transaction instruction unit 22 instructs the first user device 1A to complete or cancel the exchange transaction (processing b14, b16 of step S23).

[0053] When the first user device 1A receives instructions regarding the exchange transaction from the mediation device 2, it performs the process in step S24. When the first user device 1A receives instructions to cancel the exchange transaction from the mediation device 2, it performs processes a12 to a14. When the first user device 1A receives instructions to complete the exchange transaction from the mediation device 2, it performs processes a15 to a17.

[0054] When the first verification unit 14A receives an instruction from the mediation device 2 to cancel the exchange transaction, as process a12, the first verification unit 14A performs a verification regarding the guarantee of the mediation device 2. In process a12, the first verification unit 14A verifies whether the guarantor G1, who is trusted by the issuer K1 of the electronic value V1, guarantees the mediation device 2.

[0055] As process a13, the first verification unit 14A removes the hash value of random number n from the first valid session set. The hash value of random number n that is removed from the first valid session set is the value that was added in process a5 of step S13 of the main protocol shown in Figure 2. As process a14, the first value management unit 11A adds the electronic value V1 to the first valid value set. Process a14 is performed if the verification of process a12 is successful.

[0056] Thus, if the first request unit 15A requests the completion of the exchange transaction, and the transaction instruction unit 22 of the mediation device 2 instructs the cancellation of the exchange transaction, and the first verification unit 14A determines that the guarantor G1, who is trusted by the issuer K1 of the electronic value V1, is guaranteeing the mediation device 2, the first value management unit 11A adds the electronic value V1 to the first effective value set. This completes the cancellation process of the electronic value exchange transaction in the first user device 1A.

[0057] Upon receiving instructions from the mediation device 2 to complete the exchange transaction, the first verification unit 14A performs a verification regarding the guarantee of the mediation device 2 as process a15. In process a15, the first verification unit 14A verifies whether the guarantor G2, who is trusted by the issuer K2 of the electronic value V2, guarantees the mediation device 2.

[0058] As process a16, the first verification unit 14A removes the hash value of the random number n from the first set of valid sessions. Process a16 is the same as process a13. As process a17, the first value management unit 11A adds the electronic value V2 to the first set of valid values. Process a17 is performed if the verification of process a15 is successful.

[0059] Thus, the first value management unit 11A adds the electronic value V2 to the first effective value set when the first request unit 15A requests the completion of the exchange transaction, the transaction instruction unit 22 of the mediation device 2 instructs the completion of the exchange transaction, and the first verification unit 14A determines that the guarantor G2, who is trusted by the issuer K2 of the electronic value V2, guarantees the mediation device 2. As a result, the completion process of the electronic value exchange transaction is completed in the first user device 1A.

[0060] Next, the processing sequence of the Abort protocol in which the second user device 1B requests the arbitration device 2 to cancel the exchange transaction will be described. Figure 4 is a diagram showing the processing sequence of the Abort protocol. As shown in Figure 4, as processing a21 of step S31, the second verification unit 14B transmits the hash value of the random number n used for verification processing, etc., to the arbitration device 2. The second selection unit 13B also transmits the arbitration device 2 (information for identifying the selected arbitration device 2) selected by the first selection unit 13A of the first user device 1A to the arbitration device 2. This hash value of the random number n is the value obtained by hashing the random number n that was added to the second session set in processing b4 of step S12 shown in Figure 2.

[0061] The second request unit 15B requests the transaction instruction unit 22 of the mediation device 2 to cancel the electronic value exchange transaction. In other words, if the exchange transaction with the first user device 1A is interrupted while the electronic value V2 has been deleted from the second effective value set by the second value management unit 11B, the first request unit 15A requests the transaction instruction unit 22 of the mediation device 2 to cancel the exchange transaction.

[0062] When the mediation device 2 receives a request from the second user device 1B to cancel the exchange transaction of electronic value, it performs processes b21 to b23 in step S32. Specifically, as process b21, the verification unit 21 verifies the second user device 1B that requested the cancellation of the exchange transaction. Here, the verification unit 21 verifies whether the cancellation request was sent from the second user device 1B. The verification unit 21 performs verification based, for example, on the electronic signature and public key of the second user device 1B that were sent from the second user device 1B along with the cancellation request.

[0063] As process b22, the verification unit 21 verifies whether the arbitration device 2 selected by the first user device 1A and the second user device 1B is itself (the arbitration device 2), based on the information identifying the arbitration device 2 obtained from the second user device 1B. As process b23, the verification unit 21 verifies whether a hash value of random number n exists in the valid session set (resolve). For example, process b23 is performed if the verifications in processes b21 and b22 are successful.

[0064] Next, the mediation device 2 performs the process in step S33. If, as a result of the verification in process b23, a hash value of random number n exists in the set of valid sessions (resolve), then process b24 of step S33 is performed. In process b24 (transaction instruction step), the transaction instruction unit 22 instructs the second user device 1B to complete the exchange transaction.

[0065] On the other hand, if the verification in process b23 shows that the hash value of random number n does not exist in the set of valid sessions (resolve), then processes b25 and b26 in step S33 are performed. In process b25, the verification unit 21 adds the hash value of random number n to the set of valid sessions (abort). In process b26 (transaction instruction step), the transaction instruction unit 22 instructs the second user device 1B to cancel the exchange transaction.

[0066] In this way, the verification unit 21 verifies whether the arbitration device 2 selected by the first selection unit 13A of the first user device 1A and the second selection unit 13B of the second user device 1B is itself (processing b22 of step S32). If it is itself (the arbitration device 2) that was selected as arbitration device 2, the transaction instruction unit 22 instructs the second user device 1B to complete or cancel the exchange transaction (processing b24, b26 of step S33).

[0067] When the second user device 1B receives instructions regarding the exchange transaction from the mediation device 2, it performs the process in step S34. When the first user device 1A receives instructions from the mediation device 2 to complete the exchange transaction, it performs processes a22 to a24. When the second user device 1B receives instructions from the mediation device 2 to cancel the exchange transaction, it performs processes a25 to a27.

[0068] Upon receiving instructions from the mediation device 2 to complete the exchange transaction, the second verification unit 14B performs a verification regarding the guarantee of the mediation device 2 as process a22. In process a22, the second verification unit 14B verifies whether the guarantor G1, who is trusted by the issuer K1 of the electronic value V1, guarantees the mediation device 2.

[0069] As process a23, the second verification unit 14B removes the random number n from the second set of valid sessions. The random number n removed from the second set of valid sessions is the value added in process a4 of step S12 of the main protocol shown in Figure 2. As process a24, the second value management unit 11B adds the electronic value V1 to the second set of valid values. Process a24 is performed if the verification of process a22 is successful.

[0070] Thus, the second value management unit 11B adds the electronic value V1 to the second effective value set if the second request unit 15B requests the cancellation of the exchange transaction, the transaction instruction unit 22 of the mediation device 2 instructs the completion of the exchange transaction, and the second verification unit 14B determines that the guarantor G1, who is trusted by the issuer K1 of the electronic value V1, is guaranteeing the mediation device 2. As a result, the completion process of the electronic value exchange transaction is completed in the second user device 1B.

[0071] When the second verification unit 14B receives an instruction from the mediation device 2 to cancel the exchange transaction, as process a25, the second verification unit 14B performs a verification regarding the guarantee of the mediation device 2. In process a25, the second verification unit 14B verifies whether the guarantor G2, who is trusted by the issuer K2 of the electronic value V2, guarantees the mediation device 2.

[0072] As process a26, the second verification unit 14B removes the random number n from the second set of valid sessions. Process a26 is the same as process a23. As process a27, the second value management unit 11B adds the electronic value V2 to the second set of valid values. Process a27 is performed only if the verification of process a25 is successful.

[0073] Thus, the second value management unit 11B adds the electronic value V2 to the second effective value set if the second request unit 15B requests the cancellation of the exchange transaction, the transaction instruction unit 22 of the mediation device 2 instructs the cancellation of the exchange transaction, and the second verification unit 14B determines that the guarantor G2, who is trusted by the issuer K2 of the electronic value V2, guarantees the mediation device 2. This completes the cancellation process of the electronic value exchange transaction in the second user device 1B.

[0074] As described above, if an electronic value exchange transaction is interrupted, the mediation device 2 instructs the first user device 1A or the second user device 1B to complete or cancel the exchange transaction. This mediation device 2 is selected by the first user device 1A and the second user device 1B. In other words, instead of only a predetermined specific mediation device (a fixed mediation device) performing mediation processing, it is selected each time by the user devices conducting the electronic value exchange transaction. This prevents a concentration of mediation processing requests on a specific mediation device in this electronic value exchange system 100.

[0075] Furthermore, in this electronic value exchange system 100, each device can play the role of an arbitration device, thus satisfying the need for diversity in arbitration devices. Also, in the electronic value exchange system 100, there are no restrictions on the issuers of electronic value, so anyone can issue electronic value as an issuer, thus ensuring diversity among electronic value issuers. Moreover, in the electronic value exchange system 100, there are no restrictions on the devices of the first user device 1A, the second user device 1B, and the arbitration device 2, thus ensuring diversity among devices. In this way, the electronic value exchange system 100 can guarantee scalability (the absence of restrictions on the number of electronic values ​​that can be handled or the number of transactions).

[0076] The second selection unit 13B of the second user device 1B selects mediator 2 based on the first mediator list transmitted from the first selection unit 13A of the first user device 1A and the second mediator list held by the second user device 1B. Specifically, the second selection unit 13B selects a mediator that matches in the two lists as mediator 2. As a result, the electronic value exchange system 100 can easily select mediator 2 specified by the first user device 1A and the second user device 1B using the first mediator list and the second mediator list.

[0077] The mediation device 2 is equipped with a verification unit 21 that verifies whether it is the mediation device selected by the first user device 1A or the second user device 1B when it receives a request for mediation of an exchange transaction from the first user device 1A or the second user device 1B. If this verification is successful, the transaction instruction unit 22 of the mediation device 2 instructs the first user device 1A or the second user device 1B to cancel or complete the exchange transaction. This prevents an incorrect mediation device (an unsolicited mediation device) from mediating an exchange transaction in the electronic value exchange system 100, thereby enhancing the security of exchange transactions.

[0078] The first user device 1A includes a first verification unit 14A that, when instructed by the mediation device 2 to cancel the exchange transaction, verifies whether the guarantor G1, trusted by the issuer K1 of the electronic value V1, guarantees the mediation device 2. The first value management unit 11A of the first user device 1A adds the electronic value V1 to the first effective value set if the first verification unit 14A determines that the guarantor G1, trusted by the issuer K1 of the electronic value V1, guarantees the mediation device 2. As a result, in the electronic value exchange system 100, when the first user device 1A cancels the exchange transaction, the mediation device 2 can be verified using the guarantor G1, trusted by the issuer K1 of the electronic value V1. Therefore, in the electronic value exchange system 100, the security of the exchange transaction can be enhanced when the exchange transaction is canceled.

[0079] The first user device 1A includes a first verification unit 14A that, when instructed by the mediation device 2 to complete an exchange transaction, verifies whether the guarantor G2, trusted by the issuer K2 of the electronic value V2, guarantees the mediation device 2. The first value management unit 11A of the first user device 1A adds the electronic value V2 to the first effective value set if the first verification unit 14A determines that the guarantor G2, trusted by the issuer K2 of the electronic value V2, guarantees the mediation device 2. As a result, the electronic value exchange system 100 can verify the mediation device 2 using the guarantor G2, trusted by the issuer K2 of the electronic value V2, when the first user device 1A completes an exchange transaction. Therefore, the electronic value exchange system 100 can enhance the security of exchange transactions when completing them.

[0080] The second user device 1B includes a second verification unit 14B that, when instructed by the mediation device 2 to complete the exchange transaction, verifies whether the guarantor G1, trusted by the issuer K1 of the electronic value V1, guarantees the mediation device 2. The second value management unit 11B of the second user device 1B adds the electronic value V1 to the second effective value set if the second verification unit 14B determines that the guarantor G1, trusted by the issuer K1 of the electronic value V1, guarantees the mediation device 2. As a result, the electronic value exchange system 100 can verify the mediation device 2 using the guarantor G1, trusted by the issuer K1 of the electronic value V1, when the second user device 1B completes the exchange transaction. Therefore, the electronic value exchange system 100 can enhance the security of the exchange transaction when it is completed.

[0081] The second user device 1B includes a second verification unit 14B that, when instructed by the mediation device 2 to cancel the exchange transaction, verifies whether the guarantor G2, trusted by the issuer K2 of the electronic value V2, guarantees the mediation device 2. The second value management unit 11B of the second user device 1B adds the electronic value V2 to the second effective value set if the second verification unit 14B determines that the guarantor G2, trusted by the issuer K2 of the electronic value V2, guarantees the mediation device 2. As a result, in the electronic value exchange system 100, when the second user device 1B cancels the exchange transaction, the mediation device 2 can be verified using the guarantor G2, trusted by the issuer K2 of the electronic value V2. Therefore, in the electronic value exchange system 100, the security of the exchange transaction can be enhanced when the exchange transaction is canceled.

[0082] The electronic value exchange system 100 performs a selection step in which it selects the mediation device 2 using the first selection unit 13A of the first user device 1A and the second selection unit 13B of the second user device 1B. If an electronic value exchange transaction is interrupted, the mediation device 2 performs a transaction instruction step instructing the first user device 1A or the second user device 1B to complete or cancel the exchange transaction. This method used by the electronic value exchange system 100 prevents a concentration of mediation requests on a specific mediation device.

[0083] The above description is an example of the present disclosure and is not limited to these descriptions. For example, the above embodiment describes an example of an exchange transaction of electronic value between a first user device 1A and a second user device 1B. Similarly, for example, after the first user device 1A has conducted an exchange transaction of electronic value with the second user device 1B, it can further conduct an exchange transaction of electronic value with a third user device. In this way, the electronic value exchange system can also perform exchange transactions in which electronic value is exchanged sequentially between multiple user devices.

[0084] Furthermore, the protocols described above are merely examples, and the content of each process may be modified as needed.

[0085] The systems and methods of the present disclosure have the following configurations: [1] A system for performing an exchange transaction between a first electronic value owned by a first device and a second electronic value owned by a second device, comprising: a selection unit for selecting an arbitration device by the first device and the second device; and a transaction instruction unit provided in the arbitration device for instructing the first device or the second device to complete or cancel the exchange transaction if the exchange transaction between the first device and the second device is interrupted. [2] The system according to [1], wherein the selection unit includes a first selection unit provided in the first device and a second selection unit provided in the second device, the first selection unit transmits arbitration device information for identifying the arbitration device to the second selection unit, and the second selection unit selects the arbitration device based on the acquired arbitration device information. [3] The system according to [1] or [2], wherein the mediation device further comprises a verification unit that verifies whether the mediation device is the mediation device selected by the selection unit, and the transaction instruction unit instructs the first device or the second device to complete or cancel the exchange transaction if the verification unit determines that the mediation device is the mediation device selected by the selection unit. [4] The system according to any one of [1] to [3], wherein the first device comprises a first value management unit that performs the addition and deletion of electronic value to a first effective value set possessed by the first device, and a first verification unit that verifies whether a guarantor trusted by the issuer of the first electronic value guarantees the mediation device, and the first value management unit adds the first electronic value to the first effective value set if the transaction instruction unit instructs the cancellation of the exchange transaction and the first verification unit determines that a guarantor trusted by the issuer of the first electronic value guarantees the mediation device.[5] The system according to any one of [1] to [3], wherein the first device includes a first value management unit that performs addition and deletion of electronic value to a first effective value set possessed by the first device, and a first verification unit that verifies whether a guarantor trusted by the issuer of the second electronic value guarantees the mediation device, and the first value management unit adds the second electronic value to the first effective value set when the transaction instruction unit instructs the completion of the exchange transaction and the first verification unit determines that a guarantor trusted by the issuer of the second electronic value guarantees the mediation device. [6] The system according to any one of [1] to [3], wherein the first device includes: a first value management unit that performs addition and deletion of electronic value to a first effective value set possessed by the first device; a first verification unit that verifies whether a guarantor trusted by the issuer of the first electronic value guarantees the mediation device; and a first request unit that requests the transaction instruction unit to complete the exchange transaction if the exchange transaction with the second device is interrupted while the first electronic value has been deleted from the first effective value set by the first value management unit, wherein the first value management unit adds the first electronic value to the first effective value set if the transaction instruction unit instructs the cancellation of the exchange transaction after the first request unit has requested the completion of the exchange transaction, and the first verification unit determines that a guarantor trusted by the issuer of the first electronic value guarantees the mediation device.[7] The system according to any one of [1] to [3], wherein the first device includes: a first value management unit that performs addition and deletion of electronic value to a first effective value set possessed by the first device; a first verification unit that verifies whether a guarantor trusted by the issuer of the second electronic value guarantees the mediation device; and a first request unit that requests the transaction instruction unit to complete the exchange transaction if the exchange transaction with the second device is interrupted while the first electronic value has been deleted from the first effective value set by the first value management unit, wherein the first value management unit adds the second electronic value to the first effective value set if the transaction instruction unit instructs the completion of the exchange transaction after the first request unit has requested the completion of the exchange transaction, and the first verification unit has determined that a guarantor trusted by the issuer of the second electronic value guarantees the mediation device. [8] The system according to any one of [1] to [3], wherein the second device includes a second value management unit that performs addition and deletion of electronic value to a second effective value set possessed by the second device, a second verification unit that verifies whether a guarantor trusted by the issuer of the first electronic value guarantees the mediation device, and a second request unit that requests the transaction instruction unit to cancel the exchange transaction if the exchange transaction with the first device is interrupted while the second electronic value has been deleted from the second effective value set by the second value management unit, and the second value management unit adds the first electronic value to the second effective value set if the transaction instruction unit instructs the completion of the exchange transaction after the second request unit has requested the cancellation of the exchange transaction, and the second verification unit has determined that a guarantor trusted by the issuer of the first electronic value guarantees the mediation device.[9] The system according to any one of [1] to [3], wherein the second device includes a second value management unit that performs addition and deletion of electronic value to a second effective value set possessed by the second device, a second verification unit that verifies whether a guarantor trusted by the issuer of the second value guarantees the mediation device, and a second request unit that requests the transaction instruction unit to cancel the exchange transaction if the exchange transaction with the first device is interrupted while the second electronic value has been deleted from the second effective value set by the second value management unit, and the second value management unit adds the second electronic value to the second effective value set if the transaction instruction unit instructs the cancellation of the exchange transaction after the second request unit has requested the cancellation of the exchange transaction, and the second verification unit has determined that a guarantor trusted by the issuer of the second value guarantees the mediation device.

[10] A method to be performed in a system for exchanging a first electronic value owned by a first device for a second electronic value owned by a second device, the method comprising: a selection step of the first device and the second device selecting an arbitration device; and a transaction instruction step performed in the arbitration device, the transaction instruction step of instructing the first device or the second device to complete or terminate the exchange transaction if the exchange transaction between the first device and the second device is interrupted.

[0086] The block diagram used in the description of the above embodiment shows functional units. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized using one device that is physically or logically coupled, or it may be realized using two or more physically or logically separated devices that are directly or indirectly connected (for example, using wired or wireless connections). A functional block may be realized by combining the one or more devices with software.

[0087] Functions include, but are not limited to, judgment, decision, judgment, calculation, calculation, processing, derivation, investigation, exploration, confirmation, reception, transmission, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, assumption, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating (mapping), and assigning. For example, a functional block (configuration part) that enables transmission is called a transmitting unit or transmitter. In all cases, as mentioned above, the method of implementation is not particularly limited.

[0088] For example, the electronic value exchange system 100 in one embodiment of the present disclosure may function as a computer that processes methods executed in a system for exchanging electronic value as described in the present disclosure. Figure 5 is a diagram showing an example of the hardware configuration of a first user device 1A, a second user device 1B, and an arbitration device 2 according to one embodiment of the present disclosure. The first user device 1A and the others described above may be physically configured as a computer device including a processor 1001, memory 1002, storage 1003, communication device 1004, input device 1005, output device 1006, bus 1007, etc.

[0089] In the following explanation, the term "device" can be replaced with "circuit," "device," "unit," etc. The hardware configuration of the first user device 1A, etc., may include one or more of the devices shown in the figure, or it may be configured to omit some of the devices.

[0090] Each function in the first user device 1A, etc., is realized by loading predetermined software (programs) onto hardware such as the processor 1001 and memory 1002, which allows the processor 1001 to perform calculations, control communication by the communication device 1004, and control at least one of data reading and writing in the memory 1002 and storage 1003.

[0091] The processor 1001 controls the entire computer, for example, by running an operating system. The processor 1001 may consist of a central processing unit (CPU) that includes interfaces with peripheral devices, control units, arithmetic units, registers, and so on.

[0092] Furthermore, the processor 1001 reads programs (program code), software modules, data, etc., from at least one of the storage 1003 and the communication device 1004 into the memory 1002 and executes various processes accordingly. The program used is one that causes the computer to execute at least a part of the operations described in the above embodiment. For example, each functional unit of the first user device 1A, each functional unit of the second user device 1B, and each functional unit of the arbitration device 2 may be implemented by a control program stored in the memory 1002 and running on the processor 1001, and other functional blocks may be implemented similarly. The above-described processes have been explained as being executed by one processor 1001, but they may be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 may be implemented by one or more chips. The program may also be transmitted from a network via a telecommunications line.

[0093] The memory 1002 is a computer-readable recording medium and may consist of at least one of the following: ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), RAM (Random Access Memory), etc. The memory 1002 may also be called a register, cache, main memory, etc. The memory 1002 can store executable programs (program code), software modules, etc., for carrying out a method executed in the electronic value exchange system 100 according to one embodiment of the present disclosure.

[0094] The storage 1003 is a computer-readable recording medium and may consist of at least one of the following: an optical disc such as a CD-ROM (Compact Disc ROM), a hard disk drive, a flexible disk, a magneto-optical disk (e.g., a compact disc, a digital multipurpose disc, a Blu-ray® disc), a smart card, flash memory (e.g., a card, a stick, a key drive), a floppy® disk, a magnetic strip, etc. The storage 1003 may also be called an auxiliary storage device. The above-mentioned storage medium may be, for example, a database, server, or other suitable medium including at least one of memory 1002 and storage 1003.

[0095] The communication device 1004 is hardware (transmitting / receiving device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as a network device, network controller, network card, communication module, etc. The communication device 1004 may be configured to include, for example, a high-frequency switch, duplexer, filter, frequency synthesizer, etc., in order to implement at least one of frequency division duplex (FDD) and time division duplex (TDD). The communication device 1004 may be implemented with physically or logically separated transmitting and receiving units.

[0096] The input device 1005 is an input device that accepts input from an external source (e.g., a keyboard, mouse, microphone, switch, button, sensor, etc.). The output device 1006 is an output device that outputs to an external source (e.g., a display, speaker, LED lamp, etc.). The input device 1005 and the output device 1006 may be configured as an integrated unit (e.g., a touch panel).

[0097] Furthermore, each device, such as the processor 1001 and memory 1002, is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or different buses may be configured for each device.

[0098] Furthermore, the first user device 1A, the second user device 1B, and the arbitration device 2 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), and an FPGA (Field Programmable Gate Array), and some or all of each functional block may be realized by such hardware. For example, the processor 1001 may be implemented using at least one of these hardware components. Notification of information is not limited to the embodiments / models described herein and may be performed by other methods. For example, notification of information may be performed by physical layer signaling (e.g., DCI (Downlink Control Information), UCI (Uplink Control Information)), upper layer signaling (e.g., RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling, broadcast information (MIB (Master Information Block), SIB (System Information Block))), other signals, or a combination thereof. Furthermore, RRC signaling may also be called RRC messages, such as RRC Connection Setup messages and RRC Connection Reconfiguration messages.

[0099] The processing procedures, sequences, flowcharts, etc., of each aspect / embodiment described in this disclosure may be reordered, provided they do not contradict each other. For example, the methods described in this disclosure present various step elements using exemplary order and are not limited to the specific order presented.

[0100] Input and output information may be stored in a specific location (e.g., memory) or managed using a management table. Input and output information may be overwritten, updated, or appended to. Output information may be deleted. Input information may be transmitted to other devices.

[0101] The determination may be made by a value represented by one bit (0 or 1), by a boolean value (true or false), or by a numerical comparison (for example, a comparison with a predetermined value).

[0102] Each aspect / embodiment described in this disclosure may be used individually, in combination, or switched between as needed during implementation. Furthermore, notification of specific information (e.g., notification that "X is") is not limited to explicit notification, but may also be implicit (e.g., by not providing such notification).

[0103] Although the present disclosure has been described in detail above, it will be clear to those skilled in the art that the present disclosure is not limited to the embodiments described herein. The present disclosure can be implemented in modified and altered forms without departing from the intent and scope of the present disclosure as defined by the claims. Accordingly, the descriptions in the present disclosure are illustrative and not intended to be restrictive in any way.

[0104] Software should be broadly interpreted to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, and so on, whether they are called software, firmware, middleware, microcode, hardware description languages, or by any other name.

[0105] Furthermore, software, instructions, information, etc., may be transmitted and received via a transmission medium. For example, if software is transmitted from a website, server, or other remote source using at least one of wired technologies (such as coaxial cable, fiber optic cable, twisted pair, or digital subscriber line (DSL)) and wireless technologies (such as infrared or microwave), then at least one of these wired and wireless technologies is included in the definition of a transmission medium.

[0106] The information, signals, etc. described in this disclosure may be represented using any of the various different techniques. For example, the data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0107] In addition, terms used in this disclosure and terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, at least one of the channel and symbol may be a signal (signaling). Also, a signal may be a message. Furthermore, a component carrier (CC) may be called a carrier frequency, cell, frequency carrier, etc.

[0108] Furthermore, the information, parameters, etc., described in this disclosure may be expressed using absolute values, relative values ​​from a given value, or other corresponding information. For example, wireless resources may be indicated by an index.

[0109] The names used for the parameters described above are not restrictive in any way. Furthermore, the formulas and other expressions using these parameters may differ from those expressly disclosed in this disclosure. Various channels (e.g., PUCCH, PDCCH, etc.) and information elements can be identified by any suitable name, and therefore, the various names assigned to these various channels and information elements are not restrictive in any way.

[0110] In this disclosure, terms such as "Mobile Station (MS)," "user terminal," "User Equipment (UE)," and "terminal" may be used interchangeably.

[0111] A mobile station may also be referred to by those skilled in the art as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other appropriate term.

[0112] As used in this disclosure, the terms “determining” and “determining” may encompass a wide variety of actions. “Determining” may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up, searching, or inquiring (e.g., searching in a table, database, or other data structure), or ascertaining. “Determining” may also include, for example, receiving (e.g., receiving information), transmitting (e.g., sending information), inputting, outputting, or accessing (e.g., accessing data in memory). Furthermore, "judgment" and "decision" can include considering something as having been "judged" or "decided" after resolving, selecting, choosing, establishing, comparing, etc. In other words, "judgment" and "decision" can include considering something as having been "judged" or "decided" after some action. Also, "judgment (decision)" can be reinterpreted as "assuming," "expecting," or "considering."

[0113] The terms “connected,” “coupled,” or any variation thereof, mean any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are “connected” or “coupled” with each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, “connection” may be reinterpreted as “access.” As used in this disclosure, two elements may be considered to be “connected” or “coupled” with each other using at least one of one or more wires, cables, and printed electrical connections, and, in some non-limiting and non-exclusive examples, electromagnetic energy having wavelengths in the radio frequency domain, microwave domain, and optical (both visible and invisible) domain.

[0114] In this disclosure, the phrase "based on" does not mean "based solely on" unless otherwise specified. In other words, the phrase "based on" means both "based solely on" and "based at least on."

[0115] Any reference to elements using designations such as “first,” “second,” etc., as used in this disclosure does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient way to distinguish between two or more elements. Accordingly, references to first and second elements do not imply that only two elements may be employed, or that the first element must precede the second element in any way.

[0116] Where the terms “include,” “including,” and their variations are used in this disclosure, these terms are intended to be inclusive, as is the term “comprising.” Furthermore, the term “or” as used in this disclosure is not intended to be exclusive OR.

[0117] In this disclosure, if articles are added by translation, such as a, an, and the in English, this disclosure may include the fact that the noun following these articles is plural.

[0118] In this disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "combine" may be interpreted similarly to "different."

[0119] 1A...First user device (first device), 1B...Second user device (second device), 2...Mediation device, 11A...First value management unit, 11B...Second value management unit, 13A...First selection unit, 13B...Second selection unit, 14A...First verification unit, 14B...Second verification unit, 15A...First request unit, 15B...Second request unit, 21...Verification unit, 22...Transaction instruction unit, 100...Electronic value exchange system (system).

Claims

1. A system for conducting exchange transactions between a first electronic value owned by a first device and a second electronic value owned by a second device, comprising: a selection unit for selecting an arbitration device by the first device and the second device; and a transaction instruction unit provided in the arbitration device for instructing the first device or the second device to complete or cancel the exchange transaction if the exchange transaction between the first device and the second device is interrupted.

2. The system according to claim 1, wherein the selection unit includes a first selection unit provided in the first device and a second selection unit provided in the second device, the first selection unit transmits mediation device information for identifying the mediation device to the second selection unit, and the second selection unit selects the mediation device based on the acquired mediation device information.

3. The system according to claim 1, wherein the mediation device further comprises a verification unit for verifying whether the mediation device is the mediation device selected by the selection unit, and the transaction instruction unit, when the verification unit determines that the mediation device is the mediation device selected by the selection unit, instructs the first device or the second device to complete or cancel the exchange transaction.

4. The system according to claim 1, wherein the first device comprises: a first value management unit that performs addition and deletion of electronic value to a first effective value set possessed by the first device; and a first verification unit that verifies whether a guarantor trusted by the issuer of the first electronic value guarantees the mediation device, and the first value management unit adds the first electronic value to the first effective value set when the transaction instruction unit instructs the cancellation of the exchange transaction and the first verification unit determines that a guarantor trusted by the issuer of the first electronic value guarantees the mediation device.

5. The system according to claim 1, wherein the first device comprises: a first value management unit that performs addition and deletion of electronic value to a first effective value set possessed by the first device; and a first verification unit that verifies whether a guarantor trusted by the issuer of the second electronic value guarantees the mediation device, and the first value management unit adds the second electronic value to the first effective value set when the transaction instruction unit instructs the completion of the exchange transaction and the first verification unit determines that a guarantor trusted by the issuer of the second electronic value guarantees the mediation device.

6. The system according to claim 1, wherein the first device comprises: a first value management unit that performs addition and deletion of electronic value to a first effective value set possessed by the first device; a first verification unit that verifies whether a guarantor trusted by the issuer of the first electronic value guarantees the mediation device; and a first request unit that, if the exchange transaction with the second device is interrupted while the first electronic value has been deleted from the first effective value set by the first value management unit, requests the transaction instruction unit to complete the exchange transaction, and the first value management unit adds the first electronic value to the first effective value set if the transaction instruction unit instructs the cancellation of the exchange transaction after the first request unit has requested the completion of the exchange transaction, and the first verification unit determines that a guarantor trusted by the issuer of the first electronic value guarantees the mediation device.

7. The system according to claim 1, wherein the first device comprises: a first value management unit that performs addition and deletion of electronic value to a first effective value set possessed by the first device; a first verification unit that verifies whether a guarantor trusted by the issuer of the second electronic value guarantees the mediation device; and a first request unit that, if the exchange transaction with the second device is interrupted while the first electronic value has been deleted from the first effective value set by the first value management unit, requests the transaction instruction unit to complete the exchange transaction, and the first value management unit adds the second electronic value to the first effective value set if the transaction instruction unit instructs the completion of the exchange transaction after the first request unit has requested the completion of the exchange transaction, and the first verification unit has determined that a guarantor trusted by the issuer of the second electronic value guarantees the mediation device.

8. The system according to claim 1, wherein the second device comprises: a second value management unit that performs addition and deletion of electronic value to a second effective value set possessed by the second device; a second verification unit that verifies whether a guarantor trusted by the issuer of the first electronic value guarantees the mediation device; and a second request unit that requests the transaction instruction unit to cancel the exchange transaction if the exchange transaction with the first device is interrupted while the second electronic value has been deleted from the second effective value set by the second value management unit, and the second value management unit adds the first electronic value to the second effective value set if the transaction instruction unit instructs the completion of the exchange transaction after the second request unit has requested the cancellation of the exchange transaction, and the second verification unit determines that a guarantor trusted by the issuer of the first electronic value guarantees the mediation device.

9. The system according to claim 1, wherein the second device comprises: a second value management unit that performs addition and deletion of electronic value to a second effective value set possessed by the second device; a second verification unit that verifies whether a guarantor trusted by the issuer of the second value guarantees the mediation device; and a second request unit that requests the transaction instruction unit to cancel the exchange transaction if the exchange transaction with the first device is interrupted while the second electronic value has been deleted from the second effective value set by the second value management unit, and the second value management unit adds the second electronic value to the second effective value set if the transaction instruction unit instructs the cancellation of the exchange transaction after the second request unit has requested the cancellation of the exchange transaction, and the second verification unit has determined that a guarantor trusted by the issuer of the second value guarantees the mediation device.

10. A method to be performed in a system for exchanging a first electronic value owned by a first device and a second electronic value owned by a second device, the method comprising: a selection step of selecting an arbitration device by the first device and the second device; and a transaction instruction step performed in the arbitration device, the transaction instruction step of instructing the first device or the second device to complete or terminate the exchange transaction if the exchange transaction between the first device and the second device is interrupted.

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