JP4391399B2 - Joint purchase realization apparatus and joint purchase realization method - Google Patents

Description

  The present invention relates to a joint purchase realization apparatus and a joint purchase realization method that facilitate provision of a joint purchase service with improved safety.

  A joint purchase system has been proposed in which a plurality of customers can purchase the same product at a reasonable price. For example, in the joint purchase service providing apparatus disclosed in Patent Document 1 below, based on purchase requests from a predetermined number of customers who have received a joint purchase key, payment is made at a normal price and purchases are made by all purchasers. After the procedure is completed, the discount amount is refunded. As a result, all purchasers can obtain the product immediately and can purchase the product at a reasonable price. The joint purchase key to be transmitted to the customer is generated every time an application for joint purchase from the customer is accepted. That is, the joint purchase key is a result of matching between the product and the customer every time the customer makes a purchase application for the product.

It is conceivable that information related to joint purchase is protected and security is enhanced by encrypting the joint purchase key and the purchase request in this joint purchase service providing apparatus by the encryption key management method disclosed in Patent Document 2 below. . That is, by encrypting the joint purchase key to be transmitted to the customer into the encryption key with the public key, or by dividing the secret key corresponding to the public key into a plurality of secret key pieces and transmitting it to the customer , You can enhance the security by encrypting information about joint purchases.
JP 2004-206881 A JP 2004-48479 A

  However, when the encryption method is applied to the device, a load process occurs in which a secret key is divided into secret key pieces and transmitted each time a customer makes a purchase application for a product. As a result, when applications for joint purchase are frequently made, it is difficult to provide a joint purchase service with increased safety because a large-scale and expensive server is required as the above device. There is a problem that there is.

  Therefore, an object of the present invention is to provide a joint purchase realization apparatus and a joint purchase realization method that easily and inexpensively provide a joint purchase service with improved safety.

  The joint purchase realization apparatus of the present invention is a joint purchase realization apparatus for joint purchase of goods, connected to a sales terminal used for sale of goods and a purchase terminal used for purchase of goods. (1) Generate and publish a public key, generate a secret key corresponding to the public key, divide the secret key to generate a plurality of distributed keys, and send the plurality of distributed keys to each purchasing terminal A key generation and storage means for storing copies of a plurality of distributed keys, and (2) product information related to the product, and encryption information generated by the sales terminal encrypting the authentication information used for authentication with the public key. Sales information receiving and publishing means for receiving from the sales terminal and disclosing the authentication information and the minimum purchase number information indicating the number of purchases necessary for realizing the joint purchase of the product, and (3) the purchase terminal Partial decryption of encrypted authentication information using a distributed key Purchase information receiving means for receiving the partial decryption information generated from the purchase terminal, and (4) when the number of partial decryption information received by the purchase information receiving means is equal to or greater than the number indicated by the minimum purchase quantity information, Purchase information transmitting means for decrypting the partial decryption information to generate decryption authentication information and transmitting the decryption authentication information to the sales terminal; (5) decryption authentication information transmitted by the purchase information transmission means; Purchase determination receiving means for receiving a purchase determination result from the sales terminal as to whether or not the authentication information before the terminal for encryption with the public key matches.

  According to the joint purchase realizing apparatus of the present invention, the purchase information transmitting unit determines whether or not the number of partial decryption information received by the purchase information receiving unit is equal to or greater than the number indicated by the minimum purchase number information. . As a result, when the number of pieces of partial decryption information necessary for joint purchase is prepared, decryption / decryption authentication information is generated, and joint purchase becomes possible after determining whether or not the authentication information matches. In addition, since the authentication information is encrypted by a public key cryptosystem using a public key and a private key, information related to joint purchase can be protected and security can be improved. Further, the authentication information used when selling the product is encrypted with the public key by the sales information reception / publication means, while a plurality of distributed keys are transmitted to each purchasing terminal by the key generation / storage means. As a result, it is not necessary to regenerate the distributed key even if the product to be purchased is changed, so that the distributed key can be reused. As a result, it is not necessary to use an expensive server having a high processing capacity, and a joint purchase service with improved safety can be provided easily and inexpensively.

  Also, (6) partial decryption information generated by the purchase terminal, code information generated by calculation corresponding to the distributed key received by the purchase terminal, and code information used for verification of the distributed key, and the purchase Payment information and partial decoding information necessary for payment of a product when a terminal identifier for identifying the terminal is received from the purchase terminal and the purchase terminal can be identified by the partial decoding information, the code information, and the terminal identifier The payment information storage means for storing the code information and the terminal identifier in association with each other, and (7) the number of partial decryption information received by the payment information storage means when the purchase information transmission means generates the decryption authentication information. When the number of pieces of partial decryption information is equal, the partial decryption information is decrypted based on the partial decryption information and the terminal identifier to generate decryption settlement information, and the decryption settlement information is transmitted to the sales terminal. It is determined by the sales terminal that the settlement information decryption and transmission means, (8) the decryption settlement information transmitted by the settlement information decryption and transmission means, and the authentication information before the sales terminal encrypts with the public key match. In this case, it is preferable to further include a payment determination execution unit that performs payment of the product based on the payment information stored in the payment information storage unit.

  Thereby, the payment information storage means determines whether the purchase terminal can be identified from the partial decryption information, the code information, and the terminal identifier. For this reason, since the identity of the terminal for purchase which is going to perform joint purchase can be confirmed and non-repudiation can be prevented, the information regarding joint purchase can be protected and safety can be further improved. Further, when it is determined that the decrypted payment information and the authentication information match, the payment can be settled by the payment determination execution means. As a result, the settlement of the product in the joint purchase can be performed safely. Further, the settlement information decryption and transmission means determines whether or not the number of partial decryption information received by the settlement information storage means is equal to the number of partial decryption information when the purchase information transmission means generates the decryption authentication information. It has been broken. As a result, if the partial decryption information is equal to the number of partial decryption information when joint purchase is possible, the product is settled. As a result, it is not necessary to use an expensive server having a high processing capacity, and a joint purchase service with improved safety can be provided easily and inexpensively.

  The purchase information transmitting means decrypts the partial decryption information when the number of partial decryption information received by the purchase information reception means is equal to the number of a plurality of distributed keys transmitted by the key generation storage means. When the authentication information is generated, the decryption authentication information is transmitted to the sales terminal, and the number of the partial decryption information received by the purchase information receiving means is less than the number of the plurality of distributed keys transmitted by the key generation storage means. A partial key obtained by decrypting the partial decryption information and generating the decryption authentication information from the key generation storage means, and partially decrypting the encrypted authentication information disclosed by the sales information reception and publication means It is also preferable to generate decryption information, decrypt the generated partial decryption information and the partial decryption information received by the purchase information receiving means to generate decryption authentication information, and transmit the decryption authentication information to the sales terminal. .

  Thereby, when the number of partial decryption information received by the purchase information receiving means is equal to the number of a plurality of distributed keys transmitted by the key generation storage means, the decryption authentication information can be generated. Further, when the number of partial decryption information received by the purchase information receiving means is less than the number of distributed keys, the distributed key necessary for generating the decryption authentication information is taken out from the key generation storage means, It is possible to generate partial decryption information using a key and decrypt the generated partial decryption information and the partial decryption information received by the purchase information receiving means to generate decryption authentication information. For this reason, even if the minimum purchase quantity information is changed, the necessary key can be taken out and adjusted, so that the minimum purchase quantity information can be freely changed and set.

In the joint purchase realizing method of the present invention, a joint purchase realizing apparatus for joint purchase of the product is connected to a sales terminal used for selling the product and a purchase terminal used for purchasing the product. a joint purchase implemented method for performing, (1) joint purchase realization apparatus, and publish generates a public key to generate a secret key corresponding to the public key, a plurality of distributed key by dividing the secret key A key generation and storage step of transmitting the plurality of distributed keys to each of the purchasing terminals and storing a copy of the plurality of distributed keys; and (2) product information relating to the product, when selling the product The authentication information used for the authentication of the product is generated by the sales terminal encrypting the public key with the public key, and the minimum purchase number information indicating the number of purchases necessary for realizing the joint purchase of the product. joint purchase realized from the use terminal And sales information received public step of publishing receiving location is, (3) joint the purchase terminal partial decryption information to the encrypted authentication information is generated by partially decoded by said distributed key from the purchase terminal A purchase information receiving step received by the purchase realizing device ; and (4) a joint purchase realizing device when the number of the partial decryption information received in the purchase information receiving step is equal to or greater than the number indicated by the minimum purchase number information. The decryption information is decrypted to generate decryption authentication information, and the decryption authentication information is transmitted to the sales terminal. (5) The purchase information transmitted step is transmitted. and decrypting the authentication information, group purchasing real whether the purchase determination result and the authentication information before the sales terminal is encrypted by the public key matches from the sales terminal A purchase decision receiving step apparatus receives, characterized in that it comprises a.

  According to the joint purchase realizing method of the present invention, in the purchase information transmitting step, it is determined whether or not the number of partial decryption information received in the purchase information receiving step is equal to or greater than the number indicated by the minimum purchase number information. . Thus, when the number of pieces of partial decryption information necessary for joint purchase is prepared, decryption authentication information is generated, and joint purchase is possible after determining whether or not the authentication authentication information matches. In addition, since the authentication information is encrypted by a public key cryptosystem using a public key and a private key, information related to joint purchase can be protected and security can be improved. Also, in the sales information reception / publication step, authentication information used for selling the product is encrypted with a public key, while in the key generation / storage step, a plurality of distributed keys are transmitted to each purchasing terminal. As a result, it is not necessary to regenerate the distributed key even if the product to be purchased is changed, so that the distributed key can be reused. As a result, it is not necessary to use an expensive server having a high processing capacity, and a joint purchase service with improved safety can be provided easily and inexpensively.

  ADVANTAGE OF THE INVENTION According to this invention, the joint purchase realization apparatus and joint purchase realization method which provide the joint purchase service which improved safety | security easily and cheaply can be provided.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.

  A joint purchase realization apparatus, which is an embodiment of the present invention, will be described with reference to FIG. FIG. 1 is a diagram for explaining the joint purchase realizing device 1. The joint purchase realizing apparatus 1 physically includes a CPU (Central Processing Unit), a storage device such as a memory and a hard disk, a communication device such as a modem and a LAN card, an input device such as a mouse and a keyboard, a display device such as a display, and the like. It is configured as a computer system (or a collection of computer systems).

  The joint purchase realization apparatus 1 is roughly divided into functional components such as a key generation storage unit (key generation storage unit) 2, a sales information reception disclosure unit (sales information reception disclosure unit) 3, and a purchase information reception unit (purchase information). Receiving means) 4, purchase information transmitting section (purchasing information transmitting means) 5, purchase determination receiving section (purchase determination receiving means) 6, first code generating section (first code generating means) 7, settlement information storage section (settlement information) A storage unit) 8, a settlement information decryption transmission unit (settlement information decryption transmission unit) 9, and a settlement determination execution unit (settlement determination execution unit) 10.

  The key generation storage unit 2 includes a public key generation unit 11, a secret key generation unit 12, a distributed key generation unit 13, a distributed key transmission unit 14, and a distributed key storage unit 15. The sales information reception / publishing unit 3 includes a sales information receiving unit 16 and a sales information disclosure unit 17. The purchase information transmission unit 5 includes a purchase information decryption unit 19 and an authentication information transmission unit 20. The payment information storage unit 8 includes a payment information reception unit 23 and an information storage unit 24. The settlement information decryption / transmission unit 9 includes a settlement information decryption unit 26 and a settlement information transmission unit 27. The payment determination execution unit 10 includes a payment determination reception unit 28 and a payment execution unit 29.

  Here, apart from the joint purchase realizing device 1, there are a purchase terminal 40 and a sales terminal 50 that can communicate with the joint purchase realizing device 1.

  The purchase terminal 40 is a communication terminal used by each of a plurality of customers who jointly purchase products. Examples of the purchase terminal 40 include a mobile phone, a PDA (Personal Digital Assistance), a personal computer, and the like. The terminal 40 for purchase transmits the partial decoding information 4a, the second code information 23a, and the terminal identifier 23b to the joint purchase realizing device 1. Further, the distributed key 13a is received from the joint purchase realizing apparatus 1. The description regarding the information etc. transmitted / received is mentioned later.

  The sales terminal 50 is a communication terminal used by a merchant that sells products. Examples of the sales terminal 50 include a host computer, a server, and a personal computer. The sales terminal 50 transmits the product information 16a, the encrypted authentication information 16b, the minimum purchase quantity information 16c, the purchase determination result 6a, and the settlement determination result 28a to the joint purchase realizing device 1. Further, the sales terminal 50 receives the decryption authentication information 19a and the decryption settlement information 26a from the joint purchase realizing device 1. The description regarding the information etc. transmitted / received is mentioned later.

  Subsequently, each component of the joint purchase realizing device 1 will be described. The public key generation unit 11 is a part that generates the public key 11a and publishes the generated public key 11a to a trader or a producer who uses the sales terminal 50. The public key 11a can be generated using, for example, an RSA encryption method that is a standard encryption method. Thereby, the information regarding joint purchase can be protected and safety can be enhanced. When the generated public key 11a is disclosed to a trader or the like, it may be performed by, for example, transmitting the address of a home page on which the public key 11a is posted to the trader or the like.

  The secret key generation unit 12 is a part that generates a secret key 12 a corresponding to the public key 11 a generated by the public key generation unit 11. The secret key generation unit 12 generates the secret key 12a using the encryption method used when generating the public key 11a.

  The distributed key generation unit 13 is a part that divides the secret key 12a generated by the secret key generation unit 12 to generate a plurality of distributed keys 13a. The secret key 12a is divided using a threshold encryption algorithm. The number of distributed keys to be generated is arbitrarily determined, but is greater than the number of purchase terminals 40 that may be jointly purchased. Thereby, the distributed key can be transmitted to each of all the purchase terminals 40 participating in the joint purchase.

  The distributed key transmitting unit 14 is a part that transmits a plurality of distributed keys 13 a generated by the distributed key generating unit 13 to each of the purchase terminals 40. The transmission of the plurality of distributed keys 13a to each of the purchase terminals 40 is performed before the joint purchase is performed. Thereby, the terminal 40 for purchase will be in the state which can be decoded at any time. Even if the product to be purchased changes, the distributed key 13a need not be reproducible, so that the distributed key can be reused. In addition, description regarding participation in joint purchase using the distributed key 13a of the purchase terminal 40 will be described later.

  The distributed key storage unit 15 is a part that stores a copy of a plurality of distributed keys 13 a transmitted by the distributed key transmission unit 14. It is necessary to ensure the security of the distributed key storage unit 15 so that information regarding the distributed key 13a stored in the distributed key storage unit does not leak to outsiders.

  The sales information receiving unit 16 is a part that receives the product information 16a, the encrypted authentication information 16b, and the minimum purchase quantity information 16c transmitted from the sales terminal 50. The merchandise information 16a is information related to merchandise that can be purchased through joint purchase, and may include text information and image information. The encrypted authentication information 16b is information generated by the sales terminal 50 encrypting the authentication information 51 used for authentication when selling a product with the public key 11a. It is determined whether or not the transaction is correct by comparing the authentication information 51 possessed by the vendor using the sales terminal 50 with the decryption authentication information 19a generated from the partial decryption information 4a transmitted by the purchase terminal 40. The minimum purchase number information 16c is information regarding the purchase number and purchase number of products necessary for realizing joint purchase. When the desired purchase number of the product for which the joint purchase of the product is desired is less than the number indicated by the minimum purchase number information 16c of the product, the joint purchase is not realized. The customer can determine whether or not to perform joint purchase while referring to the product information 16a and the minimum purchase quantity information 16c for each product.

  The sales information disclosure unit 17 is a part that discloses the product information 16a, the encrypted authentication information 16b, and the minimum purchase quantity information 16c received by the sales information reception unit 16 to customers who use the purchase terminal 40. In the case where the product information 16a, the encrypted authentication information 16b, and the minimum purchase quantity information 16c are disclosed to customers, for example, the homepage on which the product information 16a, the encrypted authentication information 16b, and the minimum purchase quantity information 16c are posted. You may carry out by telling an address to a customer etc.

  The purchase information receiving unit 4 is a part that receives the partial decryption information 4 a transmitted by the purchase terminal 40. The partial decryption information 4a is information generated by the purchase terminal 40 by partially decrypting the encrypted authentication information 16b with the distributed key 13a. A customer using the purchase terminal 40 desires joint purchase of the product by transmitting the partial decryption information 4a of the product desired to be purchased jointly to the purchase information receiving unit 4 using the purchase terminal 40. I can express my intention.

  The purchase information decryption unit 19 generates decryption authentication information 19a by decryption when the number of partial decryption information 4a received by the purchase information reception unit 4 is equal to or greater than the number indicated by the minimum purchase number information 16c. is there. More specifically, when the number of partial decryption information 4a received by the purchase information receiving unit 4 is equal to the number of distributed keys transmitted by the distributed key transmission unit 14, decryption is performed using the partial decryption information 4a. Authentication information 19a is generated. On the other hand, when the number of partial decryption information 4a received by the purchase information receiving unit 4 is less than the number of distributed keys 13a transmitted by the distributed key transmitting unit 14, first, it is necessary to generate the decryption authentication information 19a. The distributed key 13a is taken out from the distributed key storage unit 15. Next, the encrypted authentication information 16b received by the sales information receiving unit 16 is partially decrypted with the extracted distributed key 13a to generate partial decryption information 19b. Next, the partial decryption information 4a is decrypted based on the partial decryption information 4a and the partial decryption information 19b to generate decryption authentication information 19a. (Description of the generation of the decryption authentication information 19a will be described later.)

  The authentication information transmission unit 20 is a part that transmits the decryption authentication information 19 a generated by the purchase information decryption unit 19 to the sales terminal 50. The sales terminal 50 that has received the decryption authentication information 19a determines whether the decryption authentication information 19a matches the authentication information 51 before the sales terminal 50 encrypts with the public key 11a. Next, the purchase determination result 6 a that is the determination result is transmitted to the joint purchase realizing apparatus 1.

  The purchase determination receiving unit 6 is a part that receives the purchase determination result 6 a transmitted from the sales terminal 50. If the purchase determination result 6a is a determination result that the decryption authentication information 19a and the authentication information 51 before encryption match, it can be determined that a joint purchase transaction has been established and joint purchase is possible. The description of the settlement of the product will be described later.

  The first code generation unit 7 is a part that generates the first code information 22a by calculation corresponding to each of the plurality of distributed keys 13a generated by the distributed key generation unit 13. The first code information 22a is information used for verifying whether a plurality of distributed keys 13a have been tampered with. The first code information 22a is generated by the number of the plurality of distributed keys 13a.

  The settlement information receiving unit 23 receives the partial decryption information 4a, the second code information 23a, and the terminal identifier 23b transmitted from the purchase terminal 40. The partial decryption information 4a is information generated by the purchase terminal 40 as described above. The second code information 23a is information generated by calculation corresponding to the distributed key 13a received by the purchase terminal 40. The second code information 23a is used for verification of the distributed key 13a. The terminal identifier 23b is an identifier for identifying the purchase terminal 40. Here, when the purchase information 40 can be identified using the partial decryption information 4a, the second code information 23a, and the terminal identifier 23b, the settlement information receiving unit 23 receives the partial decryption information 4a, the second code, The information 23a and the terminal identifier 23b are stored in the information storage unit 24.

  The information storage unit 24 is a part that stores the payment information 24a, the first code information 22a, the partial decryption information 4a, the second code information 23a, and the terminal identifier 23b in association with each other. The settlement information 24 a is information necessary for the settlement of the product when the customer using the purchase terminal 40 performs joint purchase, and is registered in the information storage unit 24 in advance. The settlement information 24a includes, for example, information related to a credit card held by the customer. The first code information 22 a is information generated by the first code generation unit 7. The partial decryption information 4a, the second code information 23a, and the terminal identifier 23b are information received by the settlement information receiving unit 23.

  In the settlement information decryption unit 26, the number of partial decryption information 4a stored in the information storage unit 24 is equal to the number of partial decryption information 4a when the purchase information decryption unit 19 generates the decryption authentication information 19a. In addition, the decryption settlement information 26a is generated. That is, the decryption settlement information 26a is generated when the partial decryption information 4a corresponding to the number of the partial decryption information 4a at the time when joint purchase becomes possible. The decryption settlement information 26a is generated by decrypting the partial decryption information 4a and 19b based on the partial decryption information 4a and 19b and the terminal identifier 23b.

  The settlement information transmitting unit 27 is a part that transmits the decrypted settlement information 26 a generated by the settlement information decrypting unit 26 to the sales terminal 50. The sales terminal 50 that has received the decryption settlement information 26a determines whether or not the decryption settlement information 26a matches the authentication information 51 before the sales terminal 50 encrypts with the public key 11a. Next, the payment determination result 28 a that is the determination result is transmitted to the joint purchase realizing device 1.

  The payment determination receiving unit 28 is a part that receives the payment determination result 28a. When the settlement determination result 28a is a determination result that the decrypted settlement information 26a and the authentication information 51 before encryption match, it can be determined that the joint purchase settlement has been performed. As a result, the settlement of the product in the joint purchase can be performed safely. In addition, the description about payment and shipping of goods is mentioned later.

  The settlement executing unit 29 is a part that performs settlement of the product when the settlement determination receiving unit 28 determines that the decrypted settlement information 26a matches the authentication information 51 before encryption. The product is settled based on the settlement information 24 a stored in the information storage unit 24.

  Subsequently, a case where an application for joint purchase by the purchase terminal 40 is applied to information disclosed by the sales information disclosure unit 17 will be described with reference to FIG. FIG. 2 is a chart for explaining an example of the encryption authentication information 16b that differs for each product and for each producer who produced the product.

  The vertical columns indicate the types of products included in the product group, and there are three types of products A to C. Moreover, the horizontal line shows the kind of producer which a producer group contains, and there are three kinds of producers 1-3. In addition, the number of persons in parentheses described in each of the products A to C indicates the number of purchases (minimum purchase number information 16c) necessary for realizing joint purchase of the product. For example, in order to jointly purchase the product C produced by the producer 2, it indicates that at least two purchasers are required. When applying for the joint purchase of the product, first, the purchase terminal 40 partially uses “Cc13”, which is the encrypted authentication information 16b, by “S1”, which is the distributed key 13a of the purchase terminal 40. Decrypt into Next, “S1 (Cc13)”, which is the partial decryption information 4a generated thereby, may be transmitted to the purchase information receiving unit 4. In this way, if the other decryption terminals 40 transmit the partial decryption information 4a to the purchase information receiving unit 4 in the same manner, the minimum purchase number is two, so that the purchase terminals 40 participating in the joint purchase of products Determine. Since the distribution key 13a of the purchase terminal 40 is different, the partial decryption information 4a generated by the distribution key 13a is also different.

  Subsequently, the difference in conditions for generating the decryption authentication information 19a according to the relationship between the number of the distributed keys 13a transmitted by the distributed key transmitting unit 14 and the number of the partial decryption information 4a received by the purchase information receiving unit 4 will be described with reference to FIG. 3 will be used together. FIG. 3 is a diagram showing the distributed key storage unit 15 that stores the distributed key 13a and the purchase information receiving unit 4 that has received the partial decryption information 4a. Here, description will be made assuming that the number of purchases indicated by the minimum purchase number information 16c is two.

  FIG. 3 shows that the total number of distributed keys 13 a transmitted by the distributed key transmission unit 14, that is, the total number of distributed keys 13 a stored in the distributed key storage unit 15 is five. In addition, the partial decryption information 4a received by the purchase information reception unit 4 is three, “1”, “3”, and “4”. It should be noted that the distributed key 13a and the partial decryption information 4a that are in the vertical positional relationship shown in FIG. Here, it is assumed that the partial decryption information 4a received by the purchase information receiving unit 4 is only “1”, “3”, and “4”, and the distributed key 13a transmitted by the distributed key transmitting unit 14 is “A”. ”,“ C ”, and“ E ”, which are equal to each other, the decryption authentication information 19a is decrypted by decrypting three of the partial decryption information 4a,“ 1 ”,“ 3 ”, and“ 4 ”. Is generated.

  In addition, the partial decryption information 4a received by the purchase information receiving unit 4 is “1”, “3”, and “4”, and the distributed keys 13a transmitted by the distributed key transmitting unit 14 are “A” to “E”. The number of partial decryption information 4a is less than the number of distributed keys 13a. In this case, first, the distributed keys “B” and “E” necessary for generating the decryption authentication information 19a by decrypting using the partial decryption information “1”, “3”, and “4” are obtained. Retrieved from the distributed key transmission unit 14. Next, partial decryption information 19b is generated by partially decrypting “2” and “5”, which are encryption authentication information 16b disclosed by the sales information disclosure unit 17. Then, “1”, “3”, and “4” of the generated partial decryption information 19b and the partial decryption information 4a received by the purchase information receiving unit 4 are decrypted to generate decryption authentication information 19a. At this time, when the minimum purchase number information 16c is changed from 2 to 4, the number (3) of the partial decryption information 4a received by the purchase information receiving unit 4 is the number (4) indicated by the minimum purchase number information 16c. Therefore, the decryption authentication information 19a is not generated. In this case, if the purchase information receiving unit 4 receives another partial decryption information 4a, the number (4) of the partial decryption information 4a becomes equal to or greater than the number (4) indicated by the minimum purchase number information 16c. Authentication information 19a is generated. Thereby, the minimum purchase quantity information 16c can be freely changed and set.

  Subsequently, the information stored in the information storage unit 24 will be described with reference to FIG. FIG. 4 is a chart for explaining an example of information stored in the information storage unit 24.

  As shown in FIG. 4, the information storage unit 24 stores payment information 24a, first code information 22a, partial decryption information 4a, terminal identifier 23b, and second code information 23a in association with each other. The settlement information 24a is registered in advance in the information storage unit 24. The first code information 22a is generated when the distributed key 13a is generated and stored in the information storage unit 24. On the other hand, the partial decoding information 4a, the terminal identifier 23b, and the second code information 23a are information stored by transmission from the purchase terminal 40. For example, in the “purchasing terminal 1”, “˜ /%!” Is stored in advance as the settlement information 24a, and “Gadahdfasa” is stored in advance as the first code information 22a. In addition, “S1 (Cc13)” as the partial decoding information 4a, “001” as the terminal identifier 23b, and “jafddSAfaa” as the second code information 23a are stored by transmission from the purchase terminal 40. It is shown that the partial decoding information 4a, the terminal identifier 23b, and the second code information 23a have not been received from the “purchasing terminal 3”. In addition, when the purchase information 40 can be identified using the partial decryption information 4a, the second code information 23a, and the terminal identifier 23b, the settlement information receiving unit 23 receives the partial decryption information 4a and the second code information. 23a and the terminal identifier 23b are stored in the information storage unit 24. Thereby, the identity of the terminal 40 for purchase can be confirmed, and denial prevention in joint purchase can be performed. Further, the settlement information 24a, the first code information 22a, the partial decryption information 4a, the terminal identifier 23b, and the second code information 23a can be stored in association with each other.

  Subsequently, a method for performing joint purchase using the joint purchase realizing apparatus 1 will be described with reference to the sequence diagram shown in FIG. FIG. 5 is a sequence diagram showing the order of processing for joint purchase.

  As shown in FIG. 5, first, the public key generation unit 11 generates and publicizes the public key 11a as shown in FIG. 5 at the beginning of the process of performing the joint purchase using the joint purchase realizing apparatus 1 (step S71). Next, the secret key generation unit 12 generates a secret key 12a (step S72), and the distributed key generation unit 13 divides the secret key 12a to generate a plurality of distributed keys 13a (step S73). Next, the distributed key transmitting unit 14 transmits the distributed key 13a to each purchasing terminal (step S74), and the distributed key storage unit 15 stores a copy of the distributed key 13a (step S75). Steps S71 to S75 correspond to a key generation and storage step.

  Next, the sales information receiving unit 16 receives the product information 16a, the encrypted authentication information 16b, and the minimum purchase quantity information 16c from the sales terminal 50 (step S76), and the sales information disclosing unit 17 receives the product information 16a, The encryption authentication information 16b and the minimum purchase quantity information 16c are disclosed (step S77). Note that steps S76 and S77 correspond to the sales information reception and disclosure step.

  Next, the purchase information receiving unit 4 receives the partial decryption information 4a from the purchase terminal 40 (step S78). Step S78 corresponds to a purchase information receiving step.

  When the number of partial decryption information 4a received in step S78 is equal to or greater than the number indicated by the minimum purchase information 16c, the purchase information decryption unit 19 decrypts the partial decryption information 4a and obtains the decryption authentication information 19a. Generate (step S79). Next, the authentication information transmitting unit 20 transmits the decrypted authentication information 19a to the sales terminal 50 (step S80). Steps S79 and S80 correspond to the purchase information decryption step.

  Next, the purchase determination receiving unit 6 receives the purchase determination result 6a from the sales terminal 50 (step S81). When the purchase determination result 6a is a result that the decryption authentication information 19a and the authentication information 51 before encryption match, the purchase terminal 40 that performs joint purchase is determined.

  Next, the first code generation unit 7 generates first code information 22a (step S82).

  Next, when the payment information receiving unit 23 receives the partial decryption information 4a, the second code information 23a, and the terminal identifier 23b (step S83), and the purchase terminal 40 can be specified, the information storage unit 24 The decoded information 4a, the second code information 23a, and the terminal identifier 23b are stored in association with each other (step S84).

  Next, the settlement information decryption unit 26 determines the number of partial decryption information 4a stored in the information storage unit 24, and the number of partial decryption information 4a when the purchase information decryption unit 19 generates the decryption authentication information 19a. The payment information decrypting unit 26 generates the decrypted payment information 26a (step S85), and the payment information transmitting unit 27 transmits the decrypted payment information 26a to the sales terminal 50 (step S86). .

  The settlement determination receiving unit 28 receives the settlement determination result 28a from the sales terminal 50 (step S87). If the settlement determination result 28a is a result that the decrypted settlement information 26a and the authentication information 51 before encryption match, the settlement execution unit 29 executes settlement of the product (step S88).

  Subsequently, three types of merchandise settlement methods when executing merchandise settlement will be described. There are three types of merchandise settlement methods: a delivery inspection payment method, a delivery payment method, and a payment delivery method. Here, it is assumed that the transaction is a joint purchase between a customer and a trader.

  In the delivery inspection and payment method, first, the joint purchase realization apparatus 1 settles the product amount by the settlement information 24a of the customer who uses the purchase terminal 40, and reports the completion of the settlement to the trader who uses the sales terminal 50. Next, the merchant receives the payment completion report and delivers the product to the customer. Next, the joint purchase realization apparatus 1 receives a report on the completion of the inspection of the product from the customer and pays the product amount to the supplier.

  In the delivery payment method, first, the joint purchase realization apparatus 1 settles the product amount based on the settlement information 24a of the customer who uses the purchase terminal 40, and reports the completion of settlement to the merchant who uses the sales terminal 50. Next, the supplier receives the report of completion of payment, delivers the product to the customer, and reports the completion of delivery of the product to the joint purchase realizing apparatus 1. Next, the joint purchase realizing device 1 receives the report of the completion of delivery of the product and pays the merchandise amount to the supplier.

  In the payment delivery method, first, the joint purchase realization apparatus 1 settles the merchandise amount by the settlement information 24a of the customer who uses the purchase terminal 40, and pays the merchandise amount to the trader who uses the sales terminal 50. Next, the trader receives the payment of the product amount and delivers the product to the customer.

  Although the present invention has been specifically described above based on the embodiment, the present invention is not limited to the above embodiment, and various modifications can be made. For example, by making the distributed key storage unit 15 independent as a distributed key management server, security may be further increased so that information regarding the distributed key 13a is not leaked to outsiders. In addition, the joint purchase realizing device 1 may be modified to include a plurality of servers.

  The effect of this embodiment is demonstrated using FIG. The purchase information decryption unit 19 determines whether or not the number of partial decryption information 4a received by the purchase information reception unit 4 is equal to or greater than the number indicated by the minimum purchase number information 16c. As a result, if the number of pieces of partial decryption information 4a necessary for joint purchase is prepared, joint purchase is possible. Further, since the authentication information 51 is encrypted by the public key cryptosystem using the public key generation unit 11 and the secret key generation unit 12, information related to joint purchase can be protected and safety can be enhanced. Further, the authentication information 51 used when selling the product is encrypted with the public key, while the distributed key transmitting unit 14 transmits the plurality of distributed keys 13a to each of the purchase terminals 40. As a result, it is not necessary to regenerate the distributed key 13a even if the product to be purchased is changed, so that the distributed key 13a can be reused. As a result, it is not necessary to use an expensive server having a high processing capacity, and a joint purchase service with improved safety can be provided easily and inexpensively.

It is a figure for demonstrating the joint purchase realization apparatus of this embodiment. It is a graph for demonstrating an example of encryption authentication information. It is the figure which showed the purchase information receiving part which received the distributed key storage part and partial decryption information which store a distributed key. It is a chart for demonstrating an example of the information which an information storage part stores. It is a sequence diagram which shows the order of the process which performs joint purchase.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Joint purchase realization apparatus, 2 ... Key generation storage part, 3 ... Sales information reception disclosure part, 4 ... Purchase information reception part, 4a, 19b ... Partial decryption information, 5 ... Purchase information transmission part, 6 ... Purchase determination reception part 6a ... purchase determination result, 7 ... first code generation unit, 8 ... settlement information storage unit, 9 ... settlement information decryption transmission unit, 11 ... public key generation unit, 11a ... public key, 12 ... secret key generation unit, 12a ... secret key, 13 ... distributed key generation unit, 13a ... distributed key, 14 ... distributed key transmission unit, 15 ... distributed key storage unit, 16 ... sales information receiving unit, 16a ... merchandise information, 16b ... encrypted authentication information, 16c ... Minimum purchase quantity information, 17 ... Sales information disclosure part, 19 ... Purchase information decryption part, 19a ... Decryption authentication information, 20 ... Authentication information transmission part, 22a ... First code information, 23 ... Settlement information reception part, 23a ... second code information, 23b ... terminal identifier, 24 ... information storage unit 24a ... Payment information 25 ... Terminal identification unit 26 ... Payment information decryption unit 26a ... Decrypted payment information 27 ... Payment information transmission unit 28 ... Payment determination reception unit 28a ... Payment determination result 29 ... Payment execution 40, terminal for purchase, 50, terminal for sale, 51 ... authentication information.

Claims (4)

A joint purchase realization device for joint purchase of the product, connected to a sales terminal used for selling the product and a purchase terminal used to purchase the product,
Generate and publish a public key, generate a secret key corresponding to the public key, divide the secret key to generate a plurality of distributed keys, and transmit the plurality of distributed keys to each of the purchase terminals Key generation storage means for storing copies of the plurality of distributed keys;
Product information related to the product, authentication information used for authentication when selling the product, encrypted authentication information generated by the sales terminal using the public key, and necessary to realize joint purchase of the product Sales information receiving and publishing means for receiving and publishing minimum purchase number information indicating the number of purchases from the terminal for sale;
Purchase information receiving means for receiving from the purchase terminal partial decryption information generated by the purchase terminal partially decrypting the encrypted authentication information with the distributed key;
When the number of partial decryption information received by the purchase information receiving means is equal to or greater than the number indicated by the minimum purchase quantity information, the partial decryption information is decrypted to generate decryption authentication information, and the decryption authentication is performed. Purchase information transmitting means for transmitting information to the terminal for sale;
A purchase determination result indicating whether the decryption authentication information transmitted by the purchase information transmitting unit and the authentication information before the sales terminal encrypts with the public key is received from the sales terminal. Purchase decision receiving means;
A joint purchase realizing apparatus characterized by comprising: Identify the partial decryption information generated by the purchase terminal, code information generated by calculation corresponding to the distributed key received by the purchase terminal, and the purchase terminal Payment information necessary to make a payment for the product when the terminal for purchase is identified by the partial decoding information, the code information, and the terminal identifier; Payment information storage means for storing the partial decoding information, the code information, and the terminal identifier in association with each other;
When the number of the partial decryption information received by the payment information storage means is equal to the number of the partial decryption information when the purchase information transmitting means generates the decryption authentication information, the partial decryption information and the terminal Payment information decoding and transmitting means for decoding the partial decoding information based on the identifier to generate decoded payment information, and transmitting the decoded payment information to the terminal for sale;
The payment information when the payment information is transmitted by the payment information decryption means and the sales terminal determines that the authentication information before the sales terminal is encrypted with the public key is the same; Payment determination execution means for paying the product based on the payment information stored in the storage means;
The joint purchase realizing apparatus according to claim 1, further comprising: The purchase information transmitting means includes
When the number of the partial decryption information received by the purchase information receiving means is equal to the number of the plurality of distributed keys transmitted by the key generation storage means, the partial decryption information is decrypted to obtain the decryption authentication information. Generate and send the decryption authentication information to the terminal for sale,
When the number of the partial decryption information received by the purchase information receiving means is less than the number of the plurality of distributed keys transmitted by the key generation storage means, the partial decryption information is decrypted and the decryption authentication information is obtained. The distribution key necessary for generating the key is taken out from the key generation storage means, the encrypted authentication information released by the sales information reception disclosure means is partially decrypted to generate the partial decryption information, and the generated The partial decryption information and the partial decryption information received by the purchase information receiving means are decrypted to generate the decryption authentication information, and the decryption authentication information is transmitted to the sales terminal. The joint purchase realization apparatus according to 1 or 2. A joint purchase realization method performed by a joint purchase realization device for joint purchase of the product, which is connected to a sales terminal used for selling the product and a purchase terminal used to purchase the product,
The joint purchase realizing device generates and publishes a public key, generates a secret key corresponding to the public key, divides the secret key to generate a plurality of distributed keys, and A key generation and storage step for transmitting to each of the purchasing terminals and storing a copy of the plurality of distributed keys;
Product information related to the product, authentication information used for authentication when selling the product, encrypted authentication information generated by the sales terminal using the public key, and necessary to realize joint purchase of the product Sales information reception publishing step in which the joint purchase realization apparatus receives and publishes the minimum purchase number information indicating the number of purchases from the sales terminal;
A purchase information receiving step in which the joint purchase realizing apparatus receives from the purchase terminal partial decryption information generated by the purchase terminal partially decrypting the encrypted authentication information with the distributed key;
When the number of the partial decryption information received in the purchase information receiving step is equal to or greater than the number indicated by the minimum purchase quantity information, the joint purchase realizing device decrypts the partial decryption information and decrypts authentication information. Generating purchase information and transmitting the decryption authentication information to the terminal for sale; and
And the decoded authentication information transmitted in the purchase information transmitting step, said whether the purchase determination result and the authentication information before the sales terminal is encrypted by the public key matches from the sales terminal A purchase decision receiving step received by the joint purchase realizing device ;
A joint purchase realization method characterized by comprising:

Images