JP2013197642A - Signal processing method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep data selection secret even from the owner of the data.SOLUTION: An encryption processing method includes: (A) processing S11 in which any of first encryption data block stored in a data storage unit storing therein a plurality of first encryption data blocks encrypted by a first cryptographic key according to an encryption scheme in which the order of encryption is commutative and the order of decryption is commutative is encrypted by a second cryptographic key according to the encryption scheme to generate a second encryption data block; (B) processing S13 in which the second encryption data block is transmitted to a computer retaining the first cryptographic key therein; (C) processing S23 in which a third encryption data block derived from the second encryption data block by decoding it with the first cryptographic key according to the encryption scheme is received from the computer retaining the first cryptographic key therein; and (D) processing S25 in which the third encryption data block is decrypted with the second cryptographic key according to the encryption scheme and the decrypted data block is stored in the data storage unit.

Description

  The present technology relates to data concealment technology.

  For example, when a data owner and a data analyst cooperate, the data owner may anonymize plain text data including personal information and pass it to the data analyst. A data analyst performs various analyzes using anonymized data. In some cases, the analysis result of the anonymized data is sufficient. Data may be requested from the data owner.

  For example, if anonymized data such as purchase history is analyzed and a specific individual is found to be a promising potential customer of the company, an effective advertisement can be obtained if the personal information of the specific individual can be obtained in clear text. Can be presented to that particular individual. However, the data owner knows that he is interested in a particular individual.

  Even if it is not for such advertising purposes, if the personal information of a specific individual is specified and requested with a common identifier, the data owner will know the specific individual. There is no prior art that focuses on such a problem.

JP 2001-2111168 A

  Therefore, the objective of this technique is providing the technique for concealing data selection also to a data owner in one side.

  The encryption processing method according to the first aspect of the present technology includes (A) a plurality of encryption methods that are encrypted with the first encryption key according to an encryption method in which the order of encryption is commutative and the order of decryption is commutative. By encrypting any of the first encrypted data blocks stored in the data storage unit storing the first encrypted data block with the second encryption key according to the encryption method, the second encryption A process for generating an encrypted data block, (B) a process for transmitting a second encrypted data block to a computer holding the first encryption key, and (C) a computer holding the first encryption key A process of receiving a third encrypted data block that is a result of decrypting the second encrypted data block with the first encryption key according to the encryption method; and (D) a third with the second encryption key according to the encryption method. Encrypted data block Goshi, and a process of storing in the data storage unit.

  The system according to the second aspect of the present technology includes a first computer that holds a first encryption key and a second computer that holds a second encryption key. And (A) a plurality of first encrypted data encrypted with the first encryption key in accordance with an encryption method in which the order of encryption is exchangeable and the order of decryption is exchangeable. A second encrypted data block is generated by encrypting any of the first encrypted data blocks stored in the data storage unit for storing the blocks with the second encryption key in accordance with the encryption method. (B) The second encrypted data block is transmitted to the first computer. Thereafter, the first computer (C) receives the second encrypted data block from the second computer, and (D) decrypts the second encrypted data block with the first encryption key in accordance with the above encryption method. (E) A third encrypted data block as a result of decryption is transmitted to the second computer. Then, the second computer (F) receives the third encrypted data block from the first computer, and (G) decrypts the third encrypted data block with the second encryption key according to the above encryption method. And stored in the data storage unit.

  Data selection can be kept secret from the data owner.

FIG. 1 is a diagram illustrating a system configuration example according to the embodiment. FIG. 2 is a diagram illustrating a configuration example of the first computer according to the first embodiment. FIG. 3 is a diagram illustrating an example of data stored in the first data storage unit according to the first embodiment. FIG. 4 is a diagram illustrating an example of data stored in the encryption key DB. FIG. 5 is a diagram illustrating an example of data stored in the customer DB. FIG. 6 is a diagram illustrating a configuration example of the second computer according to the first embodiment. FIG. 7 is a diagram illustrating a processing flow according to the first embodiment. FIG. 8 is a diagram illustrating an example of data stored in the second data storage unit of the first computer in the first embodiment. FIG. 9 is a diagram for explaining data conversion in the first embodiment. FIG. 10 is a diagram for explaining data conversion in the first embodiment. FIG. 11 is a diagram for explaining data conversion in the first embodiment. FIG. 12 is a diagram illustrating a processing flow according to the first embodiment. FIG. 13 is a diagram illustrating a configuration example of the first computer according to the second embodiment. FIG. 14 is a diagram illustrating a configuration example of the second computer according to the second embodiment. FIG. 15 is a diagram illustrating a processing flow according to the second embodiment. FIG. 16 is a diagram illustrating an example of data stored in the first data storage unit of the first computer. FIG. 17 is a diagram for explaining the anonymization process. FIG. 18 is a diagram illustrating an example of data stored in the second data storage unit of the first computer. FIG. 19 is a diagram illustrating an example of data stored in the second data storage unit of the first computer. FIG. 20 is a diagram illustrating an example of data conversion in the second embodiment. FIG. 21 is a diagram illustrating an example of data conversion in the second embodiment. FIG. 22 is a diagram illustrating an example of data conversion in the second embodiment. FIG. 23 is a diagram illustrating a processing flow in the third embodiment. FIG. 24 is a diagram illustrating an example of data stored in the first data storage unit of the first computer. FIG. 25 is a diagram for explaining the anonymization process according to the third embodiment. FIG. 26 is a diagram illustrating an example of data stored in the second data storage unit of the first computer. FIG. 27 is a diagram illustrating a data conversion example according to the third embodiment. FIG. 28 is a functional block diagram of a computer.

[Embodiment 1]
An example of a system configuration according to the first embodiment of the present technology is shown in FIG.

  In the present embodiment, a network 1 such as the Internet includes a first computer 3 that is a data owner computer, a second computer 5 that is a data user computer, and a third computer 7 that is a data user computer. And are connected. However, the number of data user computers is not limited to two. There may also be multiple data owner computers.

  FIG. 2 shows a configuration example of the first computer 3. The first computer 3 includes a first data storage unit 31, an encryption processing unit 33, a second data storage unit 34, a third data storage unit 35, an encryption key DB (database) 36, a customer DB 37, a communication A processing unit 38 and a settlement processing unit 39 are included.

  The first data storage unit 31 stores plaintext data. In this embodiment, for example, as shown in FIG. 3, a product ID, a product name, an outline, a price, and plaintext data are stored. In order to simplify the description, the price is assumed to be the same for all products, and may not be included.

  The encryption key DB 36 holds the encryption key of each data user. In the present embodiment, as shown in FIG. 4, a customer name (identifier of a customer who is a data user), an encryption key generation date, and key data are stored. However, the encryption key may be automatically deleted when an expiration date is set and a certain period or more elapses after generation. In addition, the encryption processing unit 33 may generate the request upon request.

Further, the encryption processing unit 33 performs encryption processing and decryption processing by an encryption method in which the order of encryption is exchangeable and the order of decryption is also exchangeable. In this encryption method, encryption with the first key is expressed as f, encryption with the second key is expressed as g, and x is plaintext data, f (g (x)) = g (f (x) ) Holds. Further, if f ⁻¹ represents decryption with the first key and g ⁻¹ represents decryption with the second key, f ⁻¹ (g ⁻¹ (f (g (x)))) = g ⁻¹ (f ⁻¹ (f (g (x)))) is established. Such an encryption method includes a Burnham cipher and a stream cipher, but is not limited thereto.

  The encryption processing unit 33 performs processing for encrypting plaintext data stored in the first data storage unit 31 and stores the processing result in the second data storage unit 34. In addition, the encryption processing unit 33 performs a decryption process on the encrypted data stored in the third data storage unit 35 and stores the processing result in the second data storage unit 34.

  The payment processing unit 39 is a processing unit that executes payment processing well known to customers.

  About customer DB37, the data of the purchase history of the customer who is a data user is stored. For example, data as shown in FIG. 5 is stored. In the example of FIG. 5, the customer name, customer contact information (for example, email address), purchase date, and purchase data (specifically, data received from the customer and encrypted with the customer's key) are stored. It has come to be. Since the contact information uses data such as another database, it may not be stored in this database.

  The communication processing unit 38 communicates with the second computer 5 and the third computer 7. The communication processing unit 38 stores data received from the second computer 5 or the like in the third data storage unit 35, and reads data to be transmitted to the second computer 5 or the like from the second data storage unit 34.

  FIG. 6 shows a configuration example of the second computer 5. The third computer 7 has the same configuration. The second computer 5 includes a communication processing unit 51, a first data storage unit 52, an output unit 53, an encryption processing unit 54, a second data storage unit 55, an input unit 56, and an encryption key storage unit 57. And a third data storage unit 58. The communication processing unit 51 communicates with the first computer 3, stores received data in the first data storage unit 52, and reads data to be transmitted from the third data storage unit 58.

  The output unit 53 outputs the data stored in the first data storage unit 52 or the second data storage unit 55 to an output device (for example, a printer or a display device). The input unit 56 gives instructions to the encryption processing unit 54 and the communication processing unit 51. The encryption key storage unit 57 stores the encryption key used in the encryption processing unit 54.

  The encryption processing unit 54 performs encryption and decryption by the same encryption method as the encryption processing unit 33 in the first computer 3. In particular, the encryption processing unit 54 performs superimposition encryption on the encrypted data stored in the first data storage unit 52 in accordance with an instruction from the input unit 56 and transmits the encrypted data to the first computer 3. Are stored in the third data storage unit 58. The encryption processing unit 54 performs a decryption process on the encrypted data stored in the first data storage unit 52 and stores the decrypted data in the second data storage unit 55.

  Next, processing contents of the system shown in FIG. 1 will be described with reference to FIGS.

  First, when the input unit 56 of the second computer 5 receives an instruction to download data (for example, content) from the user, the input unit 56 instructs the communication processing unit 51 to transmit a download request. In response to this, the communication processing unit 51 transmits a content request to the first computer 3 (FIG. 7: step S1).

  When the communication processing unit 38 of the first computer 3 receives the content request from the second computer 5 (step S3), the communication processing unit 38 outputs the content request to the encryption processing unit 33. The encryption processing unit 33 reads the requesting customer's encryption key K1 from the encryption key DB 36 (however, not the customer but only the first computer 3), and further the first data storage unit The plaintext content data is read from 31 and the content data is encrypted by a predetermined commutative encryption method for each title of the content data, thereby generating encrypted content data and storing it in the second data storage unit 34 To do. For example, data as illustrated in FIG. 8 is stored in the second data storage unit 34. The example of FIG. 8 includes a price, a product name, an outline, and encrypted content data. Thus, additional data for selecting encrypted content data is attached to the encrypted content data. If x is plaintext data and f represents encryption by the customer's encryption key K1 in the first computer 3, f (x) is generated.

  Then, the communication processing unit 38 transmits the encrypted content data stored in the second data storage unit 34 to the requesting second computer 5 (step S5).

  When receiving the encrypted content data or the like from the first computer 3, the communication processing unit 51 of the second computer 5 stores it in the first data storage unit 52 (step S7). The output unit 53 prompts the user to select encrypted content data by outputting additional data of the encrypted content data stored in the first data storage unit 52 to a display device or the like. The user selects the encrypted content data to be purchased from the price, the product name, and the outline. Then, when the user designates the purchase desired content, the input unit 56 receives the designation of the purchase desired content from the user (step S9), and outputs an instruction of the purchase desired content to the encryption processing unit 54. The encryption processing unit 54 reads out its own encryption key K2 from the encryption key storage unit 57, further reads out the encrypted content data of the content desired to be purchased from the first data storage unit 52, and superimposes it with a predetermined commutative encryption method. Encryption processing is performed, and the processing result is stored in the third data storage unit 58 (step S11). Assuming that the encryption using the encryption key K2 is g, in this example, f (x) is set to g (f (x)) in the above-described example. Further, in the example of FIG. 8, when the product name CCC is selected, the encrypted content data as shown in FIG. 9A is converted into the superimposed content data as shown in FIG. 9B. . In this way, the first computer 3 does not know what is selected.

  Then, the communication processing unit 51 transmits the content data stored in the third data storage unit 58 and superimposed and encrypted to the first computer 3 (step S13).

  The communication processing unit 38 of the first computer 3 receives the content data superimposed and encrypted from the second computer 5 and stores it in the third data storage unit 35 together with data (customer identifier) specifying the transmission source. (Step S15). The communication processing unit 38 causes the payment processing unit 39 to perform payment processing (step S17). The payment process may be a well-known method such as credit card payment. Since this settlement processing is not the main point of the present embodiment, it will not be described further. However, if the settlement process fails, the subsequent processes are not performed. The following processing is performed when the settlement processing is successful.

When the settlement process is successful, the encryption processing unit 33 stores the request source stored in the encryption key DB 36 for the content data stored in the third data storage unit 35 and superimposed and encrypted. Decryption processing is performed with the encryption key K1 using a commutative encryption method, and the processing result is stored in the second data storage unit 34 (step S19). In the example described above, g (f (x)) is received. Therefore, assuming that decryption by the encryption key K1 is f ⁻¹ , f ⁻¹ (g (f (x)) = f ⁻¹ ( f (g (x)) = g (x) is obtained, and when data as shown in FIG. 9B (= FIG. 10A) is received, it is decrypted with the encryption key K1, and FIG. b) content data encrypted with the encryption key K2 is obtained as described above, so that even if decrypted by the first computer 3, it is encrypted with the encryption key K2, so I don't know if the content was selected.

  Further, the communication processing unit 38 registers the encrypted content data stored in the second data storage unit 34 in the customer DB 37. This makes it possible to cope with a situation where the customer has accidentally deleted the content data. In the example of FIG. 5, data on the purchaser B is registered as the current processing result. Then, the communication processing unit 38 transmits the encrypted content data stored in the second data storage unit 34 to the requesting second computer 5 (step S21).

When the communication processing unit 51 of the second computer 5 receives the encrypted content data from the first computer 3, it stores it in the first data storage unit 52 (step S23). Then, the encryption processing unit 54 decrypts the encrypted content data stored in the first data storage unit 52 using the encryption key K2 stored in the encryption key storage unit 57 using a commutative encryption method, Store in the second data storage unit 55. Then, the output unit 53 outputs the decrypted content data (step S25). Since the encrypted content data g (x) is received as described above, when decryption by the encryption key K2 is represented by g ⁻¹ , plain text data of g ⁻¹ (g (x)) = x is obtained. It is done. Also, since encrypted content data as shown in FIG. 11A is received, plaintext data in FIG. 11B is obtained.

  In this way, the data user can purchase plaintext content data without presenting to the data owner which content has been selected.

  As described above, the customer may delete the plaintext content data by mistake. Therefore, for example, processing as shown in FIG. 12 can be performed, and the purchased content data can be decrypted again.

  That is, in response to the redownload instruction to the input unit 56, the communication processing unit 51 transmits a redownload request including the customer identifier to the first computer 3 (step S31). When receiving the redownload request including the customer identifier from the second computer 5 (step S33), the communication processing unit 38 of the first computer 3 searches the customer DB 37 with the customer identifier and reads out the corresponding data. Then, the communication processing unit 38 generates a request source purchase list from the read data (step S35), and transmits the request source purchase list to the second computer 5 (step S37). As described above, since it is not known which content data has been purchased, the purchase list includes the purchase date (or date and time) and the like.

  When the communication processing unit 51 of the second computer 5 receives the purchase list from the first computer 3, the communication processing unit 51 outputs the purchase list to the output unit 53 and displays it on the display device, for example (step S39). The user designates the purchase date of the content data for which re-downloading is requested from the purchase list. When the input unit 56 receives designation of the purchase date of the content data from the user, the input unit 56 outputs a content re-download instruction including the designation of the purchase date to the communication processing unit 51. The communication processing unit 51 transmits a content redownload request including designation of a purchase date or the like to the first computer 3 (step S41).

  When the communication processing unit 38 of the first computer 3 receives the content re-download request including the purchase date designation from the second computer 5 (step S43), the communication processing unit 38 reads the corresponding encrypted content data from the customer DB 37 and applies the corresponding encryption. The encrypted content data is transmitted to the second computer 5 (step S45).

  Upon receiving the encrypted content data from the first computer 3, the communication processing unit 51 of the second computer 5 stores it in the first data storage unit 52 (step S47). Then, the encryption processing unit 54 decrypts the encrypted content data stored in the first data storage unit 52 by a commutative encryption method using the encryption key K2 stored in the encryption key storage unit 57, and performs processing. The result is stored in the second data storage unit 55. Then, the output unit 53 outputs the plaintext content data stored in the second data storage unit 55 to an output device such as a display device (step S49).

  In this way, the lost content data can be acquired again without maintaining the confidentiality of selection and purchasing it again.

[Embodiment 2]
Next, application to a field different from the first embodiment will be described. For example, it is assumed that the data owner is a company that conducts questionnaire surveys for general users. For example, a data owner asks a general user for a questionnaire about new products, collects questionnaire results, performs aggregation processing, and holds the data. The questionnaire results are provided to data analysts who utilize the questionnaire results after anonymizing part of the data so that personal information does not go out as it is.

  On the other hand, the data analyst obtains the anonymized questionnaire results, the results of the tabulation processing, and the like from the data owner and performs the original analysis processing. However, it is efficient to perform a sales activity such as selecting a general user individually based on this analysis process and distributing an advertisement to the selected general user. However, because it is anonymized, specific personal information will be obtained from the data owner, but if you specify "which general user", which general user you are interested in Will be notified to the data owner. Therefore, it is preferable to adopt this embodiment as described below.

  Also in this embodiment, the basic system configuration is the same as that of the first embodiment. However, the first computer 3 is changed to a configuration like the first computer 3b shown in FIG. Components having substantially the same functions as those in the first embodiment are given the same reference numerals. Also, the second computer 5 is changed to a configuration like the second computer 5b shown in FIG.

  The first computer 3b according to the present embodiment includes a first data storage unit 31, a second data storage unit 34, a third data storage unit 35, an encryption key DB 36, an encryption processing unit 33, and a communication processing unit. 38 and an anonymization processing unit 40. An anonymization processing unit 40 is added, and the anonymization processing unit 40 generates anonymized data. The anonymization processor 40 cooperates by outputting some data to the encryption processor 37.

  Further, the second computer 5b according to the present embodiment includes a communication processing unit 51, a first data storage unit 52, an output unit 53, an encryption processing unit 54, a second data storage unit 55, and an input unit 56. An encryption key storage unit 57, a third data storage unit 58, and an analysis processing unit 59. The analysis processing unit 59 performs a predetermined analysis process using data (anonymized data) stored in the first data storage unit 52. The analysis result is displayed on the display device by the output unit 53 and presented to the user. The output unit 53 may output the anonymized data as it is to a display device or the like, and the user himself / herself may analyze it.

  Next, the processing contents of the system will be described with reference to FIGS. The data owner obtains the questionnaire result from the general user and stores it in the first data storage unit 31 together with the result of the tabulation process (FIG. 15: Step S51). This process is not shown in the main part of the present embodiment, but may be performed by a computer other than the first computer 3b. For example, data as shown in FIG. 16 is stored. In the example of FIG. 16, the member ID, member name, address, contact information (telephone number), and questionnaire response data are registered for each member. Although the user related to the questionnaire has been described as a general user, since it becomes a member from the perspective of the data owner, it will be described below as a member.

  And the anonymization process part 40 produces | generates anonymization data by implementing an anonymization process with respect to the personal information part of the data stored in the 1st data storage part 31 according to a predetermined rule. And stored in the second data storage unit 34 together with the questionnaire result. The anonymized member ID included in the anonymized data is output to the encryption processing unit 33. For example, for the data in FIG. 16, as schematically shown in FIG. 17, the member name is deleted, the portion below the address city is deleted, and the contact information is deleted. Further, the member ID is converted into a different value by a hash function or the like. Accordingly, data as shown in FIG. 18 is stored in the second data storage unit 34. The converted member ID is output to the encryption processing unit 33.

  In addition, the encryption processing unit 33 converts a part of the data (name, address, contact information) stored in the first data storage unit 31 for each member ID to a customer (that is, data) stored in the encryption key DB 36. The encryption key K1 for the analyst) is encrypted using a commutative encryption method and stored in the second data storage unit 34 (step S53). The processing result of the encryption processing unit 33 is data as shown in FIG. 19, for example. In the example of the data in FIG. 19, for each member ID after anonymization obtained from the anonymization processing unit 40, the name, address, and contact data are encrypted in association with the member ID after the anonymization. An example in which the result is stored is shown.

  Thereafter, the communication processing unit 38 uses the questionnaire result stored in the second data storage unit 34 and the anonymized data and the encrypted data of the personal information as the second computer 5b, which is a computer of a data analyst designated in advance. (Step S55). The communication processing unit 51 of the second computer 5b receives the questionnaire result and the anonymized data and the encrypted data of the personal information from the first computer 3b, and stores them in the first data storage unit 52 (step S57).

  Then, the analysis processing unit 59 performs a predetermined analysis process using the data stored in the first data storage unit 52, and outputs the analysis result from the output unit 53 (step S59). Note that the data analyst himself may analyze the data stored in the first data storage unit 52 without performing the processing of the analysis processing unit 59. For this reason, step S59 is represented by a dotted line block in FIG.

  The data analyst designates one or more members based on the analysis result. When the input unit 56 receives a member designation from the data analyst, the input unit 56 outputs the member designation to the encryption processing unit 54. The encryption processing unit 54 reads out the encrypted data of the personal information of the designated member among the data stored in the first data storage unit 52, and stores the encrypted data in the encryption key storage unit 57. The process is superposed with the stored encryption key K2 and encrypted by a commutative encryption method, and the processing result is stored in the third data storage unit 58 (step S61). If the encrypted personal information of the second member in the data of FIG. 19 (FIG. 20 (a)) is encrypted with the encryption key K2, it is superimposed and encrypted as shown in FIG. 20 (b). Personal information can be obtained.

  Then, the communication processing unit 51 transmits the personal information stored in the third data storage unit 58 and superimposed and encrypted to the first computer 3b (step S63). Then, the communication processing unit 38 of the first computer 3b receives the personal information superimposed and encrypted from the second computer 5b and stores it in the third data storage unit 35 together with, for example, the identifier of the second computer 5b (step). S65).

  The encryption processing unit 33 reads the encryption key K1 for the request source in the encryption key DB 36 from the identifier of the second computer 5b stored in the third data storage unit 35, and stores it in the third data storage unit 35. The superposed and encrypted personal information is decrypted by a commutative encryption method using the encryption key K1, and the processing result is stored in the second data storage unit 34 (step S67). As a result, personal information encrypted with the encryption key K2 is generated. For example, if personal information encrypted in an overlapping manner as shown in FIG. 21A is decrypted with the encryption key K1, the personal information encrypted with the encryption key K2 as shown in FIG. can get. In this way, the first computer 3b does not know which member has been selected.

  Accordingly, the communication processing unit 38 reads the encrypted personal information from the second data storage unit 34 and transmits it to the requesting second computer 5b (step S69). The communication processing unit 51 of the second computer 5b receives the encrypted personal information from the first computer 3b and stores it in the first data storage unit 52 (step S71). Then, the encryption processing unit 54 uses the encryption key K2 stored in the encryption key storage unit 57 to decrypt the encrypted personal information stored in the first data storage unit 52 using the encryption method. And the processing result is stored in the second data storage unit 55. The encrypted personal information as shown in FIG. 22A is converted into plain text personal information as shown in FIG. 22B and can be used. That is, if the output unit 53 outputs the plain text personal information stored in the second data storage unit 55 to the output device (step S73), the data analyst can use this personal information for sales activities and the like. It becomes like this.

  As described above, only the data encrypted with the encryption key K2 is transmitted to the first computer 3b, so it is not possible to know which member has been selected in the first computer 3b.

[Embodiment 3]
In this embodiment, application examples for other fields will be described. This embodiment shows an application example in the medical field. For example, when a patient conducts a medical examination in a hospital with personal information concealed, a data owner such as a city office in advance sets the patient identification number. Distribute to patients and data analysts. Further, the data owner encrypts personal information including the patient contact information and distributes it to the hospital together with the examination data and the like. When the patient comes to the hospital, sees the patient, conducts a test, and recognizes that there is a problem, the hospital encrypts the patient's encrypted personal information and sends it to the data owner. . Since the data owner is also encrypted at the data analyst hospital, it is not known which patient's personal information it is. Here, the data owner decrypts the superimposed personal information and sends it back to the hospital. The hospital can notify the patient of the test result and the like by further decrypting with his / her encryption key and acquiring the plaintext personal information.

  Such processing can be executed with the same configuration as the system configuration in the second embodiment, but the processing contents will be described below with a processing flow as shown in FIG.

  In the present embodiment, it is assumed that data as shown in FIG. 24 is stored in the first data storage unit 31. In the example of FIG. 24, the patient serial number, name, contact information, address, sex, date of birth, height, weight, test value A, and test value B are set for each patient. include. Although an example in which an email address is used as the contact information is shown, a telephone number or the like may be used.

  Then, the concealment processing unit 40 performs anonymization processing of the data stored in the first data storage unit 31, and stores the processing result in the second data storage unit 34 (FIG. 23: step S81). In the case of the data example of FIG. 24, as shown in FIG. 25, an anonymization process is performed in which the patient number is converted into a random ID and the address is deleted from the prefecture. In addition, about random ID, a patient's consultation is smoothly performed by notifying a patient himself / herself.

  In addition, the encryption processing unit 33 encrypts the contact information stored in the first data storage unit 31 using the hospital encryption key K1 stored in the encryption key DB 36 using a commutative encryption method. 2 is stored in the data storage unit 34 (step S83). Then, data as shown in FIG. 26 is stored in the second data storage unit 34.

  The communication processing unit 38 of the first computer 3b transmits the anonymized personal information and the encrypted contact information stored in the second data storage unit 34 to the second computer 5b (step S85). When the communication processing unit 51 of the second computer 5b receives the anonymized personal information and the encrypted contact information from the first computer 3b, it stores them in the first data storage unit 52 (step S87).

  After this, the patient goes to the hospital, notifies the notified ID, and receives a diagnosis and examination. The doctor in the hospital examines and examines the patient and makes a decision such as reexamination. Note that a part of the analysis by the analysis processing unit 59 may be performed (step S89). In the figure, since it is performed manually, it is represented by a dotted line block. Then, for example, a doctor or the like inputs the ID of the patient who needs reexamination to the second computer 5b through the input unit 56.

  When receiving the input of the patient ID, the input unit 56 of the second computer 5 b outputs the patient ID to the encryption processing unit 54. When receiving the patient ID, the encryption processing unit 54 reads out the encrypted contact information associated with the patient ID from the first data storage unit 52, and stores the encrypted contact information in the encryption key storage unit 57. Is encrypted by being superposed by a commutative encryption method using the encryption key K2 stored in the data and stored in the third data storage unit 58 (step S91). For example, when the ID “4398” in FIG. 25 is input, the contact information encrypted in a superimposed manner as shown in FIG. 27A is generated. Thus, since the encryption key K2 is also encrypted, the first computer 3b cannot identify who is the patient who has been reexamined.

  The communication processing unit 51 of the second computer 5b transmits the contact information stored in the third data storage unit 58 and superimposed and encrypted to the first computer 3b (step S93). When the communication processing unit 38 of the first computer 3b receives the contact information that is superimposed and encrypted from the second computer 5b, the communication processing unit 38 stores it in the third data storage unit 35 (step S95).

  The encryption processing unit 33 exchanges encrypted contact information stored in the third data storage unit 35 using the encryption key K1 for the hospital stored in the encryption key DB 36. The data is decrypted by the method and stored in the second data storage unit 34 (step S97). Contact information encrypted with the encryption key K2 as shown in FIG. 27B is obtained.

  Then, the communication processing unit 38 transmits the encrypted contact information stored in the second data storage unit 34 to the second computer 5b (step S99). The communication processing unit 51 of the second computer 5b receives the encrypted contact information from the first computer 3b and stores it in the first data storage unit 52 (step S101). Then, the encryption processing unit 54 decrypts the encrypted contact information stored in the first data storage unit 52 with the encryption key K2 stored in the encryption key storage unit 57 using a commutative encryption method, and the decryption result Is stored in the second data storage unit 55 (step S103). Then, the output unit 53 outputs the plain text contact information stored in the second data storage unit 55 to the output device. As shown in FIG. 27 (c), the decryption result is a plain mail address as contact information, so that a re-examination or the like can be notified.

  As a result, the hospital can notify the patient of reexamination and the like. At this time, the city hall, which is the data owner, keeps a secret of who is reexamined.

  Although the embodiment of the present technology has been described above, the present technology is not limited to this. For example, the application field as described above is an example, and can be applied to other fields.

  Furthermore, the functional configurations of the first and second computers described above are examples, and do not necessarily match the actual program module configurations. The configuration of the data storage unit may not match the actual file configuration.

  As for the processing flow, as long as the processing result does not change, the order of the processing steps may be changed or executed in parallel.

  Further, the first and second computers may be realized by a plurality of computers instead of a single computer. Furthermore, although the example in which the encrypted data is first distributed to the second computer via the network 1 is shown, it may be distributed by other methods. In other words, mail may be sent.

  The first computer 3 and the second and third computers 5 and 7 described above are computer devices, and as shown in FIG. 28, a memory 2501, a CPU (Central Processing Unit) 2503, and a hard disk drive. A bus 2519 includes an HDD (Hard Disk Drive) 2505, a display control unit 2507 connected to the display device 2509, a drive device 2513 for the removable disk 2511, an input device 2515, and a communication control unit 2517 for connecting to a network. It is connected. An operating system (OS: Operating System) and an application program for executing the processing in this embodiment are stored in the HDD 2505, and are read from the HDD 2505 to the memory 2501 when executed by the CPU 2503. The CPU 2503 controls the display control unit 2507, the communication control unit 2517, and the drive device 2513 according to the processing content of the application program, and performs a predetermined operation. Further, data in the middle of processing is mainly stored in the memory 2501, but may be stored in the HDD 2505. In an embodiment of the present technology, an application program for performing the above-described processing is stored in a computer-readable removable disk 2511 and distributed, and installed from the drive device 2513 to the HDD 2505. In some cases, the HDD 2505 may be installed via a network such as the Internet and the communication control unit 2517. Such a computer apparatus realizes various functions as described above by organically cooperating hardware such as the CPU 2503 and the memory 2501 described above and programs such as the OS and application programs. .

  The above-described embodiment can be summarized as follows.

  In the encryption processing method according to the present embodiment, (A) a plurality of first encryptions encrypted with a first encryption key according to an encryption method in which the encryption order is commutative and the decryption order is commutative. A second encrypted data block is obtained by encrypting any of the first encrypted data blocks stored in the data storage unit that stores the encrypted data block with the second encryption key in accordance with the encryption method. (B) processing for transmitting the second encrypted data block to the computer holding the first encryption key, and (C) the above encryption from the computer holding the first encryption key. A process of receiving a third encrypted data block that is a result of decrypting the second encrypted data block with the first encryption key according to the method; and (D) a third encryption with the second encryption key according to the encryption method. Data block And, and a process of storing in the data storage unit.

  In this way, it is possible to keep secret which data block has been selected on the first computer side.

  Note that the encryption processing method includes (E) a process of requesting the computer holding the first encryption key to retransmit the third encrypted data block, and (F) from the computer holding the first encryption key, A process of receiving the third encrypted data block according to the request; and (G) a process of decrypting the third encrypted data block with the second encryption key in accordance with the encryption method and storing it in the data storage unit. It may be included. Even if the plaintext data block is lost, the plaintext data block can be restored if the third encrypted data block can be acquired again.

  Furthermore, in the above cryptographic processing method, there is a case where at least a part of anonymized data is associated with each of the plurality of first encrypted data blocks. It becomes possible to determine which first encrypted data block should be selected based on such anonymized data.

  It is possible to create a program for causing a computer to carry out the processing described above, such as a flexible disk, an optical disk such as a CD-ROM, a magneto-optical disk, and a semiconductor memory (for example, ROM). Or a computer-readable storage medium such as a hard disk or a storage device.

  The following supplementary notes are further disclosed with respect to the embodiments including the above examples.

(Appendix 1)
Stored in a data storage unit for storing a plurality of first encrypted data blocks encrypted with a first encryption key in accordance with an encryption scheme in which the order of encryption is commutative and the order of decryption is commutative A process of generating a second encrypted data block by encrypting any of the first encrypted data blocks with a second encryption key according to the encryption method;
Processing for transmitting the second encrypted data block to a computer holding the first encryption key;
Receiving a third encrypted data block, which is a result of decrypting the second encrypted data block with the first encryption key according to the encryption method, from a computer holding the first encryption key;
A process of decrypting the third encrypted data block with the second encryption key according to the encryption method and storing it in the data storage unit;
And a cryptographic processing method executed by a computer.

(Appendix 2)
A process of requesting the computer holding the first encryption key to retransmit the third encrypted data block;
Receiving the third encrypted data block according to the request from the computer holding the first encryption key;
A process of decrypting the third encrypted data block with the second encryption key according to the encryption method and storing it in the data storage unit;
The encryption processing method according to appendix 1, further comprising:

(Appendix 3)
The encryption processing method according to appendix 1 or 2, wherein each of the plurality of first encrypted data blocks is associated with data that is at least partially anonymized.

(Appendix 4)
Stored in a data storage unit for storing a plurality of first encrypted data blocks encrypted with a first encryption key in accordance with an encryption scheme in which the order of encryption is commutative and the order of decryption is commutative A process of generating a second encrypted data block by encrypting any of the first encrypted data blocks with a second encryption key according to the encryption method;
Processing for transmitting the second encrypted data block to a computer holding the first encryption key;
Receiving a third encrypted data block, which is a result of decrypting the second encrypted data block with the first encryption key according to the encryption method, from a computer holding the first encryption key;
A process of decrypting the third encrypted data block with the second encryption key according to the encryption method and storing it in the data storage unit;
A program that causes a computer to execute.

(Appendix 5)
Stored in a data storage unit for storing a plurality of first encrypted data blocks encrypted with a first encryption key in accordance with an encryption scheme in which the order of encryption is commutative and the order of decryption is commutative An encryption processing unit that generates a second encrypted data block by encrypting any of the first encrypted data blocks with a second encryption key according to the encryption method;
The second encrypted data block is transmitted to the computer holding the first encryption key, and the first encryption key is used for the first encryption key according to the encryption method from the computer holding the first encryption key. A communication unit that receives a third encrypted data block that is a result of decrypting the two encrypted data blocks;
Have
The cryptographic processing unit
An information processing apparatus that decrypts the third encrypted data block with the second encryption key according to the encryption method, and stores the decrypted third encrypted data block in the data storage unit.

(Appendix 6)
A first computer holding a first encryption key;
A second computer holding a second encryption key;
Have
The second computer comprises:
Stored in a data storage unit for storing a plurality of first encrypted data blocks encrypted with a first encryption key in accordance with an encryption scheme in which the order of encryption is commutative and the order of decryption is commutative Encrypting any of the first encrypted data blocks with a second encryption key according to the encryption scheme, thereby generating a second encrypted data block;
Sending the second encrypted data block to the first computer;
The first computer is
Receiving the second encrypted data block from the second computer;
Decrypting the second encrypted data block with the first encryption key according to the encryption scheme;
Sending a third encrypted data block as a result of decryption to the second computer;
The second computer comprises:
Receiving the third encrypted data block from the first computer;
A system in which the third encrypted data block is decrypted with the second encryption key according to the encryption method and stored in the data storage unit.

31 First data storage unit 34 Second data storage unit 35 Third data storage unit 36 Encryption key DB
33 Encryption processing unit 38 Communication processing unit 40 Anonymization processing unit 51 Communication processing unit 52 First data storage unit 53 Output unit 54 Encryption processing unit 55 Second data storage unit 56 Input unit 57 Encryption key storage unit 58 Third data storage unit 59 Analysis processing section

Claims (6)

Stored in a data storage unit for storing a plurality of first encrypted data blocks encrypted with a first encryption key in accordance with an encryption scheme in which the order of encryption is commutative and the order of decryption is commutative A process of generating a second encrypted data block by encrypting any of the first encrypted data blocks with a second encryption key according to the encryption method;
Processing for transmitting the second encrypted data block to a computer holding the first encryption key;
Receiving a third encrypted data block, which is a result of decrypting the second encrypted data block with the first encryption key according to the encryption method, from a computer holding the first encryption key;
A process of decrypting the third encrypted data block with the second encryption key according to the encryption method and storing it in the data storage unit;
And a cryptographic processing method executed by a computer. A process of requesting the computer holding the first encryption key to retransmit the third encrypted data block;
Receiving the third encrypted data block according to the request from the computer holding the first encryption key;
A process of decrypting the third encrypted data block with the second encryption key according to the encryption method and storing it in the data storage unit;
The cryptographic processing method according to claim 1, further comprising: The cryptographic processing method according to claim 1, wherein each of the plurality of first encrypted data blocks is associated with data that is at least partially anonymized. Stored in a data storage unit for storing a plurality of first encrypted data blocks encrypted with a first encryption key in accordance with an encryption scheme in which the order of encryption is commutative and the order of decryption is commutative A process of generating a second encrypted data block by encrypting any of the first encrypted data blocks with a second encryption key according to the encryption method;
Processing for transmitting the second encrypted data block to a computer holding the first encryption key;
Receiving a third encrypted data block, which is a result of decrypting the second encrypted data block with the first encryption key according to the encryption method, from a computer holding the first encryption key;
A process of decrypting the third encrypted data block with the second encryption key according to the encryption method and storing it in the data storage unit;
A program that causes a computer to execute. Stored in a data storage unit for storing a plurality of first encrypted data blocks encrypted with a first encryption key in accordance with an encryption scheme in which the order of encryption is commutative and the order of decryption is commutative An encryption processing unit that generates a second encrypted data block by encrypting any of the first encrypted data blocks with a second encryption key according to the encryption method;
The second encrypted data block is transmitted to the computer holding the first encryption key, and the first encryption key is used for the first encryption key according to the encryption method from the computer holding the first encryption key. A communication unit that receives a third encrypted data block that is a result of decrypting the two encrypted data blocks;
Have
The cryptographic processing unit
An information processing apparatus that decrypts the third encrypted data block with the second encryption key according to the encryption method, and stores the decrypted third encrypted data block in the data storage unit. A first computer holding a first encryption key; a second computer holding a second encryption key;
Have
The second computer comprises:
Stored in a data storage unit for storing a plurality of first encrypted data blocks encrypted with a first encryption key in accordance with an encryption scheme in which the order of encryption is commutative and the order of decryption is commutative Encrypting any of the first encrypted data blocks with a second encryption key according to the encryption scheme, thereby generating a second encrypted data block;
Sending the second encrypted data block to the first computer;
The first computer is
Receiving the second encrypted data block from the second computer;
Decrypting the second encrypted data block with the first encryption key according to the encryption scheme;
Sending a third encrypted data block as a result of decryption to the second computer;
The second computer comprises:
Receiving the third encrypted data block from the first computer;
A system in which the third encrypted data block is decrypted with the second encryption key according to the encryption method and stored in the data storage unit.

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