JP2003005645A - Method, system and apparatus encrypting, apparatus for decrypting and computer program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To protect individual privacy associated with personal data of patients, etc., treated in facilities associated with medical care and allow processing analysis and statistics of the data of the patients, etc. SOLUTION: An encrypting method includes a selecting process for selecting a field corresponding to an item capable of identifying an individual in a personal data file including personal records comprising a plurality of the fields having the personal data encoded, digitized and converted into text in unified format item by item, a partially encrypting process for encrypting the selected field by using the first public key, not encrypting unselected fields and producing a partially encrypted file, a wholly encrypting process for encrypting the partially encrypted file and producing a wholly encrypted file and a wholly decrypting process for decrypting the produced wholly encrypted file and reproducing the partially encrypted file.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an encryption method, an encryption system, an encryption device, a decryption device, and an encryption method used to protect the privacy of individuals related to individual data such as patient data handled in medical facilities. Belongs to the technical field of computer programs.

[0002]

2. Description of the Related Art Generally, encryption methods of this type include common key cryptography, secret key cryptography, and public key cryptography.

The common key cryptosystem is a system in which, when encrypted with one common key, the encrypted data is decrypted using the same common key.

[0004] The secret key encryption method is to disclose an algorithm of how to perform encryption so that it can be used by an unspecified number of people, while keeping the encryption key and the decryption key secret. This is a method of encryption and decryption using these secret keys. In this case, the encryption key and the decryption key are usually the same, and in general, they are often treated as synonymous with the above-mentioned common key cryptosystem. For the original purpose of encryption, it is premised that such a secret key or common key be stored so that the sender and the receiver are not known to third parties.

On the other hand, the public key cryptosystem means that when data is encrypted with a public key which is a key for encryption, the encrypted data is a decryption key different from this and is secret. It is a method of decrypting with a secret key (that is, unknown to the sender).

These various encryption methods are disclosed in, for example, Japanese Patent Laid-Open No.
000-331101, JP-A-11-10231
When used in a medical facility as disclosed in Japanese Patent Laid-Open No. 7 and Japanese Patent Application Laid-Open No. H11-053668, data is transferred during transfer or transfer of personal data such as encrypted patient data via a communication means. Even if the data is leaked or stolen, the data cannot be decrypted unless there is a common key or a secret key, and it is said that privacy related to personal data can be protected.

[0007]

However, according to the various encryption methods described above, data is handled before encryption.
For example, in a medical-related facility such as a hospital, only doctors, nurses, laboratory technicians, pharmacists, etc. who have a duty of confidentiality can see patient data, but handle data after decryption of patient data. At medical institutions, other hospitals, other medical facilities such as universities, patient data, etc. can be viewed even by researchers, investigators, clerks, etc. who do not generally have confidentiality obligations. Then, for example, even if the item related to the name of the patient is hidden on the patient data, the patient individual related to the patient data intentionally or accidentally, for example, sex, date of birth, date of hospitalization, date of discharge, There is a big problem that there is a high possibility that it will be identified from any item of patient data, such as items such as medical history and hospital history. In other words, encrypted patient data, etc. is in a state of being visible to various parties due to the nature of various statistical processing and analysis processing related to medical care after decryption, so personal data such as patient data is It will be extremely difficult in practice to protect the privacy related to. In this case, in particular, it is difficult to use the patient data for analysis for improving medical care, in the case of completely avoiding the identification of the patient. If it is available, there is a problem that it is difficult to solve the problem that if the name is hidden, the patient will be identified based on gender, date of birth, date of hospitalization, date of discharge, medical history, hospital history, etc. .

The present invention has been made in view of the above problems, and an encryption method, an encryption system, which enables analysis processing and statistical processing of personal data such as patient data while protecting the privacy of individuals such as patients. An object is to provide an encryption device, a decryption device, and a computer program that causes a computer to function as such an encryption system, an encryption device, and a decryption device.

[0009]

In order to solve the above-mentioned problems, the encryption method of the present invention codes a predetermined unit of personal data such as patient data in a unified format and codes each item such as medical-related items. In a personal data file, such as a patient data file, that includes at least one personal record, such as a patient record, that consists of multiple fields that are digitized, digitized, or textified, according to a predetermined standard, such as a patient individual, A selection step of selecting a field corresponding to an item that can identify an individual, and a partially encrypted file in which the selected field is encrypted with a first public key and the fields not selected in the selection step are not encrypted Partial encryption process for creating a whole encrypted file by encrypting the created partial encrypted file Comprising the entire encryption process of creating, the overall decoding process for reproducing the partial encryption file by decoding the entire encrypted file that is the created.

According to the encryption method of the present invention, first of all, in the selecting step, in a personal data file such as a patient data file including a personal record such as a patient record composed of a plurality of fields, a patient individual or the like is in accordance with a predetermined standard. Select the field corresponding to the item that can be used to identify the individual. Here, for example, in the case of a patient record, the “individual record” is a unit of records collected when handling patient data such as one hospital unit, one receipt unit, one chart unit, but more generally, It is a unit of records collected when handling some personal data. In this selection step, for example, a field corresponding to the patient ID, a field corresponding to the date of birth of the patient, a field corresponding to the date of discharge, a field corresponding to the date of admission, and the like, which can identify the patient , Etc., but more generally, a field corresponding to an item that can identify an individual is selected. The predetermined criteria regarding whether or not an individual such as a patient can be specified is empirical,
It may be set experimentally or theoretically in advance, and may be changed specifically according to the actual use environment. Then, in the partial encryption step, the fields thus selected are encrypted with the first public key and the fields not selected are not encrypted, thereby creating a partially encrypted file. Then, in the whole encryption process, the created partial encrypted file is encrypted by a known encryption method such as a common key method, a secret key method, a public key method, etc., to create an entire encryption file. . After that, the entire encrypted file is transferred from one medical-related facility such as a hospital to another medical-related facility such as a medical laboratory through a communication means such as the Internet, or is stored in a flexible disk, a CD-RAM, or the like. It is transported as it is stored in the medium. At this time, even if the whole encrypted file is leaked or stolen, the whole is encrypted, so
The meaning is never understood. After that, in a transfer or transfer destination, for example, another medical facility, etc., the whole encryption file is decrypted and the partially encrypted file is reproduced by the whole decryption process. However, according to the present invention, in the partially encrypted file reproduced in another medical-related facility as described above, the field that can identify an individual is still in the state of being encrypted with the first public key. Therefore, for example, researchers and investigators who do not generally have confidentiality obligations at other medical-related facilities such as research facilities, public institutions, other hospitals, and universities.
Even if an office worker or the like views personal data such as patient data as a part of such a partially encrypted file, the possibility that the individual concerned is specified is significantly reduced. In other words, after the transfer or transfer of personal data, for example, when various statistical processing or analysis processing related to medical care is performed, personal data such as disease name, operative method, treatment result, and therapeutic drug are visible to various parties. However, since the individual is not specified, the privacy of each individual can be protected. In this case, in particular, by adjusting the criteria for the items that can identify the individual, it is possible to use the patient data for various analyzes and statistical processing while avoiding the identification of the individual. For example, for fields corresponding to name, sex, date of birth, date of hospitalization, medical history, hospital history, etc. on patient data, if the above-mentioned predetermined criteria are set in advance so that the meaning is not understood, partial There is little or no practical meaning to identify a patient by looking at the encrypted file. Conversely, if you look at the unencrypted fields, for example, how many times has this patient been hospitalized so far? Have you been hospitalized before? What kind of treatment did you do before? Such information can be analyzed without identifying an individual, and various statistical processing and analysis processing such as case analysis, hospital evaluation, operative method evaluation, and drug evaluation can be performed.

As described above, according to the encryption method of the present invention,
It becomes possible to perform analysis processing and statistical processing of personal data while protecting individual privacy.

In one aspect of the encryption method of the present invention, the selected field of the reproduced partially encrypted file is decrypted with a first secret key corresponding to the first public key to obtain the patient data file. It further comprises a partial decoding step of reproducing.

According to this aspect, in the partial decryption step, the field which is still encrypted in the reproduced partial encrypted file is decrypted by the first secret key corresponding to the first public key, For example, a personal data file such as a patient data file is reproduced. Therefore, if only the specific person, such as the attending physician, who has a duty of confidentiality regarding the personal data is informed of the first secret key, only this person can see all the decrypted personal data.

Alternatively, in another aspect of the encryption method of the present invention,
The selection step selects the field stepwise according to a plurality of stepwise standards as the predetermined standard, and the partial encryption step selects the field selected stepwise,
The encryption is performed with the first public key that is different for each stage.

According to this aspect, the predetermined standard by which an individual can be specified is divided into stages. For example, names, addresses, patient IDs, etc., which make it very easy to identify an individual, are the first criteria, and birth dates, hospitalization dates, discharge dates, etc. are the second criteria, and the length of hospitalization and medical history , Chronic medical history, etc. are set to the third standard, and the field is encrypted with the first public key that is different for each stage according to these standards. Therefore, it is possible to perform encryption with different encryption keys according to the ease of individual identification, and finally it is possible to perform decryption with different decryption keys.

In this aspect, the stepwise selected field of the partially encrypted file reproduced by the whole decryption step is decrypted by the first secret key corresponding to the first public key which is different for each step. It may further include a partial decoding step.

According to this structure, the partially encrypted file after decryption is notified of different secret keys to persons with different positions such as the director, deputy director, secretary general, researcher, and clerk. Can change the type of personal data, such as patient data, that can be viewed according to its position.
Therefore, it is very convenient because it is possible to provide necessary personal data according to the position while protecting the privacy of the individual.

In another aspect of the encryption method of the present invention, the whole encryption step includes a step of encrypting the partial encryption file with a common key, and a step of encrypting the common key with a second public key. And a step of decrypting the common key with a second secret key corresponding to the second public key, and a step of decrypting the entire encrypted file with the decrypted common key. Including and

According to this aspect, the whole encrypted file is encrypted by the second public key, which is the encrypted public key, in the whole encryption process, and when the whole encrypted file is transferred, Security against leakage and theft during transportation can be improved.

Alternatively, in another aspect of the encryption method of the present invention,
The whole encryption step encrypts the partially encrypted file with a second public key, and the whole decryption step decrypts the whole encrypted file with a second secret key corresponding to the second public key. .

According to this aspect, the entire encrypted file is
Since it cannot be decrypted without the second secret key, it is possible to improve security against leakage or theft during transfer or transfer of the entire encrypted file.

In another aspect of the encryption method of the present invention, an individual I is recorded for each individual record in the partially encrypted file.
The method further includes the step of assigning a record identifier different from the D code, wherein the partial encryption step encrypts the selected field so that statistical processing or analysis processing of the personal record can be performed based on the record identifier. To do.

According to this aspect, the partially encrypted file is stored, for example, in the patient ID, while protecting the privacy of the individual.
Instead, it is possible to perform statistical processing or analysis processing based on a record identifier given to each patient record such as a unit of hospitalization, and it is also possible to construct a database such as a medical information database. For example, the same code is converted into the same code, the same digital value is converted into the same digital value, or the same text is converted into the same text. The statistical processing and analysis processing such as hospital evaluation, case analysis, operative method evaluation, and drug evaluation can be performed in the encrypted state (that is, the state in which an individual cannot be specified). Moreover, if a related organization or a person with a confidentiality obligation performs a partial decryption process using the first secret key corresponding to the first public key used when partially encrypting the field, It is also possible to see all the personal data on the results of statistical processing and analysis processing.

In order to solve the above-mentioned problems, the encryption system of the present invention codes, digitizes or texts a predetermined unit of personal data such as patient data in a unified format for each item such as medical-related items. In a personal data file, such as a patient data file, that includes at least one personal record, such as a patient record, that is composed of multiple fields, it is possible to specify an individual, such as a patient individual, according to a predetermined standard. Selecting means for selecting a field corresponding to an item, and partial encryption for encrypting the selected field with the first public key and creating a partially encrypted file without encrypting the fields not selected by the selecting means And a means for encrypting the created partial encrypted file to create an entire encrypted file. Comprising encrypting means, and the whole decoding unit by decoding the entire encrypted file that is the created to reproduce the partial encrypted file.

According to the encryption system of the present invention, first, the field corresponding to the item in which the individual can be specified according to a predetermined standard in the personal data file including the personal record including the plurality of fields by the selecting means. Select. Then, the partial encryption means encrypts the fields selected in this way with the first public key and does not encrypt the fields not selected.
Create a partially encrypted file. Then, the entire encryption means encrypts the created partial encryption file to create an entire encryption file. After that, the whole encrypted file is transferred through a communication means such as the Internet or transferred while being stored in a storage medium. At this time, even if the whole encrypted file is leaked or stolen, the whole is encrypted and the meaning is not understood. After that, at the transfer or transfer destination, for example, at another medical-related facility or the like, the whole decryption means decrypts the whole encrypted file to reproduce the partially encrypted file.

Therefore, according to the encryption system of the present invention, as in the case of the above-described encryption method of the present invention, it becomes possible to perform analysis processing and statistical processing of personal data while protecting the privacy of the individual, and finally Personal data can be effectively used in various industries such as medical care.

In one aspect of the encryption system of the present invention, the selected field of the reproduced partially encrypted file is decrypted with a first secret key corresponding to the first public key to obtain the patient data file. It further comprises a partial decoding means for reproducing.

According to this aspect, the partial decryption means decrypts the still encrypted field in the reproduced partial encrypted file with the first secret key corresponding to the first public key, Play a personal data file. Therefore, if only the specific person who has a confidentiality obligation about the personal data is informed of the first secret key, only this person can see all the decrypted personal data.

Alternatively, in another aspect of the encryption system of the present invention, the selecting means selects the field stepwise according to a plurality of stepwise standards as the predetermined standard, and the partial encryption means performs the stepwise selection. The field selected in step 1 is encrypted with the first public key that differs for each stage.

According to this aspect, the predetermined standard by which the individual can be specified is divided into stages, and the field is encrypted with the first public key which is different for each stage according to these. Therefore, it is possible to perform encryption with different encryption keys according to the ease of individual identification, and finally it is possible to perform decryption with different decryption keys.

In this aspect, the stepwise selected field of the partially encrypted file reproduced by the whole decryption means is decrypted by the first secret key corresponding to the first public key which is different for each stage. It may further include a partial decoding means for performing.

According to this structure, the partially encrypted file after decryption is notified to persons of different positions with different secret keys, so that the types of personal data that can be viewed according to the positions are changed. To be Therefore, it is very convenient because it is possible to provide necessary personal data according to the position while protecting the privacy of the individual.

In another aspect of the encryption system of the present invention, the whole encryption means includes means for encrypting the partially encrypted file with a common key, and means for encrypting the common key with a second public key. The whole decryption means includes means for decrypting the common key with a second secret key corresponding to the second public key, and means for decrypting the whole encrypted file with the decrypted common key. Including and

According to this aspect, the whole encryption file is encrypted by the whole encryption file with the second public key, which is the encrypted public key, when the whole encryption file is transferred. Security against leakage and theft during transportation can be improved.

Alternatively, in another aspect of the encryption system of the present invention, the full encryption means encrypts the partially encrypted file with a second public key, and the full decryption means uses the second public key.
The whole encrypted file is decrypted with the second secret key corresponding to the public key.

According to this aspect, the entire encrypted file is
Since it cannot be decrypted without the second secret key, it is possible to improve security against leakage or theft during transfer or transfer of the entire encrypted file.

In another aspect of the encryption system of the present invention, the partial encryption means further includes means for giving a record identifier different from the individual ID code to each of the individual records, to the partial encryption file. The selected field is encrypted so that the personal record can be statistically processed or analyzed based on the record identifier.

According to this aspect, it is possible to perform statistical processing or analysis processing on the partially encrypted file based on the record identifier given to each individual record while protecting the privacy of the individual, and construct various databases. It is also possible. For example, in the case of an encryption method in which the same value is changed to the same value, various statistical processing and analysis processing can be performed in the encrypted state (state in which an individual cannot be specified). Moreover, if a related organization or a person with a confidentiality obligation performs a partial decryption process using the first secret key corresponding to the first public key used when partially encrypting the field, It is also possible to see all the personal data on the results of statistical processing and analysis processing.

In order to solve the above-mentioned problems, the encryption device of the present invention has at least one personal record consisting of a plurality of fields in which a predetermined unit of personal data is coded, digitized or textified for each item in a uniform format. Selecting means for selecting a field corresponding to an item capable of identifying an individual according to a predetermined standard in the included personal data file; and the selecting means for encrypting the selected field with a first public key. A partial encryption unit that creates a partially encrypted file without encrypting the fields that are not selected by, and an entire encryption unit that creates an entire encrypted file by encrypting the created partially encrypted file.

According to the encryption apparatus of the present invention, first, the selecting means selects, according to a predetermined standard, in the personal data file including the personal record including a plurality of fields.
Select the field that corresponds to the item that can identify the individual. Then, the partial encryption means encrypts the fields thus selected with the first public key and does not encrypt the unselected fields to create a partially encrypted file. Then, the entire encryption means encrypts the created partial encryption file to create an entire encryption file. After that, even if the whole encrypted file is leaked or stolen when it is transferred through a communication means such as the Internet or transferred while being stored in a storage medium, Is encrypted, so its meaning cannot be understood.

In order to solve the above-mentioned problems, the decrypting device of the present invention decrypts the whole encrypted file created by the above-mentioned encrypting device of the present invention and reproduces the partial encrypted file. Equipped with.

According to the decryption apparatus of the present invention, the entire encryption file is transferred or transferred to the entire encryption file created by the encryption apparatus, such as another medical facility, by the total decryption means. Decrypt the encrypted file and play the partially encrypted file. Therefore, according to the decryption device of the present invention, it is possible to analyze personal data and perform statistical processing while protecting the privacy of the individual.

In one aspect of the decryption device of the present invention, the selected field of the reproduced partial encryption file is decrypted with a first secret key corresponding to the first public key, and the personal data file is decrypted. It further comprises a partial decoding means for reproducing.

According to this aspect, the partial decryption means decrypts the still encrypted field in the reproduced partial encrypted file with the first secret key corresponding to the first public key, Play a personal data file. Therefore, if only the specific person who has a confidentiality obligation about the personal data is informed of the first secret key, only this person can see all the decrypted personal data.

In order to solve the above problems, the first computer program of the present invention causes a computer to function as the above-described encryption system of the present invention (however, including its various aspects).

According to the first computer program of the present invention, a CD-R storing the computer program.
If the computer program is read from a recording medium such as an OM or a DVD-ROM and executed by the computer, or if the computer program is downloaded through the communication means and then executed, the encryption of the present invention is performed. The system can be constructed relatively easily.

In order to solve the above problems, the second computer program of the present invention causes a computer to function as the above-described encryption device of the present invention.

According to the second computer program of the present invention, a CD-R storing the computer program.
If the computer program is read from a recording medium such as an OM or a DVD-ROM and executed by the computer, or if the computer program is downloaded through the communication means and then executed, the encryption of the present invention is performed. It is comparatively easy to construct the optimization device.

In order to solve the above problems, the third computer program of the present invention causes a computer to function as the above-mentioned decoding device of the present invention.

According to the third computer program of the present invention, a CD-R storing the computer program.
If the computer program is read from a recording medium such as an OM or a DVD-ROM and executed by the computer, or if the computer program is downloaded through the communication means and then executed, the decoding of the present invention described above. It is comparatively easy to construct the optimization device.

The operation and other advantages of the present invention will be apparent from the embodiments described below.

[0052]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) First, the configuration of a cryptographic system according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram of a cryptographic system according to the first embodiment.

In FIG. 1, the encryption system includes an encryption device 100a, a storage device 110, and communication means 131 and 23.
1, a first decoding device 200a, a processing device 240, a storage device 250, and a second decoding device 300.

In the storage device 110, a patient data file 111 including a plurality of patient records consisting of a plurality of fields in which a predetermined unit of patient data is coded, digitized or textified for each medical-related item in a unified format. Is being built. Here, the “patient record” is a unit of records collected when handling patient data such as one hospitalization unit, one receipt unit, and one chart unit.

The encryption device 100a includes a field selection means 101, a partial encryption means 102, and a whole encryption means 10.
3 is provided. These means are, for example, the encryption device 100.
CPU (Central Processi)
ng Unit). Encryption device 100
The a further includes input means 104 such as a keyboard, a mouse, a switch and a card reader. The first public key and the common key are input via the input means 104.

The field selecting means 101 is the storage device 1.
In the patient data file 111 constructed in 10, the fields corresponding to the items that can identify the individual patient are selected according to a predetermined standard. Here, for example, the field corresponding to the patient name,
Select the field corresponding to the item that can identify the patient, such as the field corresponding to the patient ID, the field corresponding to the date of birth of the patient, the field corresponding to the date of discharge, the field corresponding to the date of admission, etc. To do. The predetermined standard for determining whether or not an individual such as a patient can be specified is empirically, experimentally, and theoretically set in advance.

The partial encryption means 102 inputs the field selected by the field selection means 101 to the input means 1
The first public key input via 04 is used for encryption by the public key system, and the field selection means 101
The partially encrypted file 112 is configured to be created in the storage device 110 by not encrypting the fields not selected by.

The whole encryption means 103 is a storage device 110.
The partially encrypted file 112 created in the file is encrypted by the common key method using the common key input via the input means 104, and the entire encrypted file 113 is created in the storage device 110. It is configured.

The communication means 131 is configured to transmit the whole encrypted file 113 created in the storage device 110 to the communication means 231 via the Internet 150 by a predetermined protocol.

On the other hand, the communication means 231 is configured to receive the whole encrypted file 113 transmitted after such encryption via the Internet by a predetermined protocol.

The present embodiment is applicable not only to the Internet 150 as such a communication line but also to various lines such as wired, wireless, dedicated line, and general line.

On the other hand, the first decoding device 200a comprises a total decoding means 203. This means is logically constructed in, for example, the CPU of the computer which constitutes the first decoding device 200a. The first decryption device 200a further includes an input means 204 such as a keyboard, a mouse, a switch and a card reader. The same common key as the common key input to the input unit 104 on the encryption device 100a side is input via the input unit 204.

The whole decoding means 203 is the communication means 231.
Is decrypted with the common key input via the input means 204 to reproduce the partially encrypted file. Then, the processing means 240 performs a process of assigning an identifier to each patient record for the partially encrypted file thus reproduced,
The medical information database 25 is subjected to various data processing such as classification processing or conversion processing according to a predetermined rule.
1 is created in the storage device 250.

The medical information database 251 thus created is a terminal device 3 such as a plurality of personal computers or workstations connected to a storage device 250 for storing the medical information database 251.
At 10, various kinds of statistical processing and analysis processing such as case analysis, hospital evaluation, operative method evaluation, and drug evaluation are provided. And, in particular, the terminal device 310S which is at least one of the plurality of terminal devices connected to the storage device 250 in this way.
Includes a second decoding device 300.

The second decoding device 300 comprises a partial decoding means 302. This means is, for example, the second decoding device 3
00 is logically constructed in the CPU of the computer. The second decryption device 300 further includes an input means 304 such as a keyboard, a mouse, a switch, and a card reader. The first secret key corresponding to the first public key input to the input unit 104 on the encryption device 100a side is input via the input unit 304.

The partial decryption means 302 is configured to decrypt the partially encrypted file stored in the medical information database 251, and reproduce the patient data file that has not been encrypted.

Next, with reference to FIGS. 2 to 6, an encryption method in the encryption system according to the first embodiment configured as described above will be described.

First, the encryption method will be described with reference to FIGS. 2 is a flowchart of the encryption method, and FIG. 3 shows the patient data file 11
3 is a conceptual diagram showing how each record included in 1 is encrypted. FIG.

Referring to FIG. 2, first, a patient data file 111 including a patient record consisting of a plurality of fields.
In the step S1, a field corresponding to an item capable of specifying a preset patient individual is selected (step S1).
1). Here, for example, as shown in the upper part of FIG. 3, a data table 111 that constitutes the patient data file 111.
In a, a field corresponding to the patient ID, a field corresponding to the discharge date, a field corresponding to the hospitalization date, etc. are selected.

Referring again to FIG. 2, before and after step S11, the first public key used for partial encryption is acquired via the input means 104 (step S12). continue,
The fields in the patient record selected in step S11 are encrypted with the first public key acquired in step S12. Then, the partially encrypted file 112 is created by not encrypting the fields in the patient record that are not selected in step S12 (step S13).
Here, for example, as shown in the upper half of FIG. 3, in the data table 111a forming the patient data file 111, the field corresponding to the patient ID, the field corresponding to the discharge date, the field corresponding to the hospitalization date, etc. Partially encrypted file 11 encrypted with 1 public key
The data table 112a that composes No. 2 is created.

Referring again to FIG. 2, these steps S11
From before to after S13, the common key used for the overall encryption is acquired via the input means 104 (step S14).
Then, the partial encryption file 112 created in step S13 is encrypted by the common key method using the common key acquired in step S14, and the whole encryption file 113 is created (step S15). Here, for example, as shown in the lower half of FIG. 3, in the data table 112a forming the partially encrypted file 112, the entire encrypted file 113 in which all the fields are encrypted by the common key
The data table 113a which comprises

Referring again to FIG. 2, the entire encrypted file 113 thus created is transmitted from the communication means 131 to the communication means 231 via the Internet 150 (step S16), and a series of processing is completed. here,
For example, the encryption device 100a installed in one medical-related facility such as a hospital is transferred to the first decryption device 200a installed in another medical-related facility such as a medical laboratory. At this time, even if the entire encrypted file 113 is leaked or stolen in the middle of transmission, the whole is encrypted and the meaning is not understood.

Next, the decryption method in the encryption method of the present embodiment will be described with reference to FIGS. FIG. 4 is a flowchart of the decryption method, FIG. 5 is a conceptual diagram showing how each record included in the patient data file is decrypted, and FIG. 6 is an encrypted data code. FIG. 3 is a conceptual diagram showing a specific example in which is decoded.

In FIG. 4, first, the communication unit 231 receives the entire encrypted file transmitted from the communication unit 131 via the Internet 150 (step S21). Before and after this step S21, the common key used for the overall decryption in the first decryption apparatus 200a, that is, the same key as the common key used in the overall encryption means 103 in the encryption apparatus 100a is input via the input means 204. To obtain (step S22).

Then, the whole encrypted file received in step S21 is decrypted by the common key method using the common key acquired in step S22 to create a partially encrypted file (step S23). Here, for example, as shown in the upper half of FIG. 5, a data table 113a forming the entire encrypted file 113 in which all fields are encrypted.
Is totally decrypted by the common key method to create a data table 112a forming the partially encrypted file 112. That is, even with such decryption, the meaning of the field corresponding to the patient ID, the field corresponding to the discharge date, the field corresponding to the hospitalization date, etc. partially encrypted in step S13 of FIG. 2 is understood. There is no such thing.

Next, based on the patient data decrypted excluding the items in which the patient individual can be specified in this way,
Create a database (step S24). Here, for example, as shown in the middle part of FIG. 5, with respect to the data table 112a forming the partially encrypted file 112 partially decrypted in step S23, the data No. is set as an identifier different from the personal ID code. Is newly added. Then, the patient ID, the date of admission, the date of discharge, the date of birth, etc. are incorporated into the medical information database 251 as a part of the table 251a while being encrypted. In this embodiment, in particular, the partial encryption by the partial encryption unit 102 on the encryption device 100a side is performed by the data No. as an identifier.
The same code is converted to the same code, the same digital value is converted to the same digital value, or the same text is converted to the same text so that statistical processing or analysis processing of patient records can be performed based on It is carried out by the system. On the other hand, the final numbering date and the final update date, which are determined not to be able to identify the individual patient, are incorporated in the medical information database 251 as a part of the table 251a in a non-encrypted form.

Referring again to FIG. 4, in each terminal device 310, the first secret key corresponding to the first public key input via the input means 104 on the encryption device 100a side is input via the input means thereof. It is determined whether or not (step S25). For example, the input unit 304 in the terminal device 310S
When the first secret key is input via (step S25:
Yes), by the public key method using the first secret key acquired in step S25, the medical information database 251
The specific field of the patient data contained in encrypted form is decrypted (step S26). Here, for example, as shown in the lower half of FIG. 5, in the data table 251a constituting the medical information database 251, the field corresponding to the patient ID, the field corresponding to the discharge date, the field corresponding to the hospitalization date, etc. The data table 111a which comprises the patient data file 111 and which is decrypted with one private key is created. More specifically, as shown in the upper part of FIG. 6, the encrypted and meaningless patient ID (column A2), discharge date (column A3), hospitalization date (A
As shown in the lower part of FIG. 6, the 4th column) and the like are decrypted to the date of discharge, the date of hospitalization, etc., which makes sense.

Referring again to FIG. 4, after the decryption in step S26 or if the first secret key is not input in step S25 (step S25: No), for example, hospital evaluation, case analysis, operative evaluation, medication evaluation, etc. The statistical processing and analysis processing of (1) are performed (step S27), and the series of processing ends.

If the encryption method and the decryption method described above are used, a transfer destination such as a research facility, a public institution,
Even if the entire encrypted file is decrypted and the partially encrypted file is played at another medical facility such as another hospital or university,
The field that can identify the individual patient is still encrypted with the first public key. Therefore, even if a researcher, investigator, or clerk who does not have a duty of confidentiality at other medical-related facilities sees the patient data as part of such a partially encrypted file, the individual patient concerned can be identified. It rarely happens. In this case, in particular, the patient data can be used for various analyzes and statistical processing while avoiding the identification of the individual patient by adjusting the criteria for the items that can identify the individual patient. For example, how many times have a patient been hospitalized so far? Have you been hospitalized before? What kind of treatment did you do before? Information such as can be found without identifying the individual patient by looking at the unencrypted fields.

In particular, the encrypted data is subjected to statistical processing and analysis processing without specifying the individual patient, and the processing results are as follows (because it is difficult to specify the individual patient).
It is preferably not encrypted. As described above, by encrypting a certain patient data in a state in which the individual patient can be identified and using it for statistical processing and the like, it is possible to protect the privacy and effectively use the patient data for medical improvement.

Further, according to the present embodiment, if the second decryption device 300 is provided, the partially encrypted file can be decrypted using the first secret key to completely reproduce the patient data file. For this reason, if only the specific person, such as the attending physician, who has a duty of confidentiality regarding the patient data, is informed of the first secret key, only this person can see all the personal data after decryption.

In the above-described embodiment, the fields in each patient record are divided into those that are simply partially encrypted and those that are not. It is also possible to encrypt. For example, patient names, patient addresses, patient IDs, etc., which make it very easy to identify individual patients, are the first criteria, and birth dates, hospitalization dates, discharge dates, etc. are the second criteria.
As a standard, the length of hospital stay, medical history, chronic medical history, etc.
As a reference, the field is encrypted with a first public key that differs for each stage. Then, in the second decoding device 300,
If the field selected step by step is decrypted with the first secret key corresponding to the first public key that is different for each step, the partially encrypted file after decryption can be stored in, for example, the director, the deputy director, the office work. By making different first secret keys known to persons with different positions, such as the chairperson, researchers, and clerks, it is possible to see them according to their positions.

(Second Embodiment) Next, a cryptographic system according to a second embodiment of the present invention will be described with reference to FIGS. 7 to 9.

First, the configuration of the cryptographic system according to the second embodiment of the present invention will be described with reference to FIG. Figure 7
FIG. 6 is a block diagram of a cryptographic system according to a second embodiment. In FIG. 7, the same components as those of the first embodiment shown in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

In FIG. 7, the encryption system includes an encryption device 100b, a storage device 110, communication means 131 and 23.
1, a first decoding device 200b, a processing device 240, a storage device 250, and a second decoding device 300. The encryption device 100b includes the field selection unit 1
In addition to 01, the partial encryption means 102, the whole encryption means 103 and the input means 104, a common key encryption means 106 for encrypting the common key using the second public key is provided. The common key input via the input means 104 is the second key.
The public key is used to encrypt the common key encryption means 106, and the communication means 131 encrypts the entire encrypted file 113.
Sent with. On the other hand, the first decryption device 200b uses the second decryption key to decrypt the common key received together with the whole encryption file by the communication unit 231 in addition to the whole decryption unit 203 and the input unit 204. The decoding means 206 is provided. Other configurations are similar to those of the above-described first embodiment.

Next, with reference to FIGS. 8 and 9, an encryption method in the encryption system according to the second embodiment configured as described above will be described.

First, the encryption method will be described with reference to FIG. Here, FIG. 8 is a flowchart of the encryption method. In FIG. 8, the same steps as those in the first embodiment shown in FIG. 2 are designated by the same step numbers, and the description thereof will be omitted.

In FIG. 8, the processing from steps S11 to S15 is performed as in the case of the first embodiment. Next, the second public key is acquired via the input means 104 or another input means (step S31). Then, the common key encryption unit 106 encrypts the common key acquired in step S14 using the second public key obtained in step S31 (step S32). Then, step S1
Whole encrypted file 113 created in step 5 and step S
The common key encrypted in 32 is transmitted from the communication means 131 to the communication means 231 via the Internet 150 (step S33), and a series of processing is completed.

Next, the decryption method in the encryption method of this embodiment will be described with reference to FIG. Figure 9 here
Is a flowchart of the decoding method. Incidentally, FIG.
In FIG. 4, the same steps as those in the first embodiment shown in FIG. 4 are designated by the same step numbers, and the description thereof will be omitted.

In FIG. 9, first, the communication unit 231 receives the entire encrypted file and the encrypted common key transmitted from the communication unit 131 via the Internet 150 (step S41). Then, the input means 2
The second secret key corresponding to the second public key used by the common key encryption means in the encryption device 100b is acquired via 04 (step S42), and the common key decryption is performed using the acquired second secret key. The encryption unit 206 decrypts the common key (step S43).

After that, the processes of steps S22 to S27 are performed using the decrypted common key, as in the first embodiment described above.

As described in detail above, according to the second embodiment, the common key used when creating the whole encrypted file 113 is encrypted with the second public key, and the whole encrypted file Security against leakage or theft during transfer of 113 can be improved.

(Third Embodiment) Next, an encryption system according to a third embodiment of the present invention will be described with reference to FIG. FIG. 10 is a block diagram of a cryptographic system according to the third embodiment. In FIG. 10, the same components as those of the first embodiment shown in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

In FIG. 10, in the encryption system, the second public key, not the common key, is input to the input means 104 on the side of the encryption device 100a ', and the whole encryption means 103' does not use the common key method but the public key method. In response to this, the second decryption device 200a ′ side inputs the second secret key instead of the common key to the input means 204, and the whole decryption means 203 ′ does not use the common key method. It is configured to perform decryption by the public key method. Further, instead of the communication means 131, a flexible disk drive, a CD
A writing unit 132 such as a RAM drive or a DVD-RAM drive is provided, and a reading unit 232 such as a flexible disk drive, a CD drive or a DVD drive is provided instead of the communication unit 231. For other configurations,
This is similar to the case of the first embodiment described above.

Therefore, according to the third embodiment, since the whole encrypted file 113 'encrypted by the public key method cannot be decrypted without the second secret key, the whole encrypted file 113' is stored. Security against leakage and theft during transportation of the recording medium 160 can be improved.

(Fourth Embodiment) Next, a cryptographic system according to a fourth embodiment of the present invention will be described.

In the fourth embodiment, the above-mentioned first to third
In the configuration of the embodiment, the data forming the first secret key or the second secret key is divided into at least two,
Other configurations are similar to those of the above-described first to third embodiments.

Therefore, the secret key (first or second secret key)
Can be held by two parties as a private key piece. At the same time, the private key piece held by one person cannot exert its original function as a secret key, so even if one of the secret key pieces held separately by two physically separated parties is stolen. , I cannot decrypt encrypted files. As a result, the security level is significantly increased. In particular, when the secret key (first or second secret key) is divided into two in this way, a person who holds one of the secret key pieces makes a plurality of copies of this secret key piece and holds it. If you do so, the chances of losing or destroying all copies and originals at a time will be much lower. That is, as a whole, the possibility of losing the private key is extremely low. On the other hand,
Even if the possibility of leaking the private key piece increases by copying a plurality of or a large number of copies, practical problems due to leakage or theft hardly occur as long as the private key piece does not function as a secret key.

As described above, according to the fourth embodiment, it is possible to construct a very strong encryption system against theft, leakage, loss or destruction.

(Fifth Embodiment) Next, a cryptographic system according to a fifth embodiment of the present invention will be described.

In the fifth embodiment, in the configuration of the above-described fourth embodiment, fields are selected stepwise in accordance with a plurality of stepwise standards and partially encrypted. For example, patient names, patient addresses, patient IDs, etc., which make it very easy to identify an individual patient, are the first criteria, and birth dates, hospitalization dates, discharge dates, etc. are the second criteria. period,
Regarding medical history, chronic medical history, etc., the third standard is to encrypt the field with a public key that differs for each stage. Then, the private key and the private key piece are configured such that the private key piece matches the private key corresponding to any of the stepwise public keys. Other configurations are the same as those in the above-described fourth embodiment.

Therefore, by collecting the private key pieces, the private key can be obtained and the encryption system can be constructed so that the patient data file can be completely decrypted. At the same time, the private key pieces are divided into management levels. By using this as a private key, only the field corresponding to the management level can be decrypted.

As described above, according to the fifth embodiment, by dividing the secret key, a very strong encryption system against theft, leakage, loss or destruction can be obtained, and the secret key piece can be managed at a management level. By supporting the above, it is possible to construct a cryptographic system that can use a secret key piece as a stepwise secret key.

In the first to fifth embodiments described above,
The encryption devices 100a, 100b and 100a ', the first decryption devices 200a, 200b and 200a', and the second decryption device 300 are respectively personal computers,
It may be composed of a computer such as a workstation or a mobile computer. In this case, the computer program is transferred to a computer from a recording medium such as a CD-ROM or a DVD-ROM that stores a computer program that causes each computer to function as an encryption device, a first decryption device, or a second decryption device. If it is read and executed, or if it is executed after downloading the computer program through the communication means,
The encryption devices 100a and 100 according to the above-described embodiment
b and 100a ', the first decoding devices 200a and 200b
And 200a ′ and the second decoding device 300 can be constructed relatively easily.

As the public key cryptosystem in the above-mentioned embodiment, a known cryptosystem such as RSA cryptosystem can be adopted, and as the common key or secret key cryptosystem, for example, MISTY cryptosystem, DES cryptosystem or the like. Lattice encryption method can be adopted.

In addition, in each of the above-mentioned embodiments,
The patient data file to be encrypted may be a fixed-length data file having a logical structure or a data file having a document type definition. Alternatively, it may be a data file having a logical structure but having a variable length or no document type definition. For example, the patient data file may consist of an XML document that has no document type definition. In this case, the management information indicating the management level of each field is provided in the head portion of the encrypted data, and the management level is set to the management level by using the secret key stored in the IC card or the like and having the management level. It is preferable that the corresponding field is decrypted based on the management information. According to this structure, even if there is no document type definition in the patient data file, there is no particular problem in decryption. Further, by using the secret key piece as a stepwise secret key, it is possible to obtain an encryption system capable of decrypting only a specific field in a data file having no document type definition.

The present invention is not limited to the above-described embodiments, but can be appropriately modified within the scope of the gist or concept of the invention which can be read from the claims and the entire specification, and such modifications are accompanied. Encryption method, encryption system,
An encryption device, a decryption device and a computer program are also included in the technical scope of the present invention.

[0109]

As described above in detail, according to the present invention, it becomes possible to perform analysis processing and statistical processing of personal data such as patient data while preserving the privacy of the individual. Data can be effectively used in various industries such as medical care.

[Brief description of drawings]

FIG. 1 is a block diagram of a cryptographic system according to a first embodiment of the present invention.

FIG. 2 is a flowchart of an encryption method according to the first embodiment.

FIG. 3 is a conceptual diagram showing how each record included in a patient data file according to the first embodiment is encrypted.

FIG. 4 is a flowchart of a decoding method according to the first embodiment.

FIG. 5 is a conceptual diagram showing how each record included in a patient data file according to the first embodiment is decrypted.

FIG. 6 is a conceptual diagram showing a specific example in which an encrypted data code is decrypted in the first embodiment.

FIG. 7 is a block diagram of a cryptographic system according to a second embodiment of the present invention.

FIG. 8 is a flowchart of an encryption method according to the second embodiment.

FIG. 9 is a flowchart of a decoding method according to the second embodiment.

FIG. 10 is a block diagram of a cryptographic system according to a third embodiment of the present invention.

[Explanation of symbols]

100a, 100b, 100a '... Encryption device 101 ... Field selection means 102 ... Partial encryption means 103 ... Whole encryption means 104 ... Input means 106 ... Common key encryption means 111 ... Patient data file 112 ... Partially encrypted file 113, 113 '... Whole encrypted file 200a, 200b, 200a '... Decoding device 203, 203 '... Whole decoding means 204 ... Input means 206 ... Common key decryption means 240 ... Processing means 250 ... Storage device 251 ... Medical Information Database 300 ... Second decoding device 302 ... Partial decoding means 304 ... Input means

Claims (20)

[Claims] 1. A personal data file comprising at least one personal record consisting of a plurality of fields in which a predetermined unit of personal data is coded, digitized or textified for each item in a uniform format according to a predetermined standard. A selection step of selecting a field corresponding to an item that can identify an individual, and a partially encrypted file in which the selected field is encrypted with a first public key and the fields not selected in the selection step are not encrypted And a partial encryption step of encrypting the created partial encrypted file to create an entire encrypted file, and a partial encryption step of decrypting the created entire encrypted file An entire decryption step of reproducing a file. 2. A partial decryption step of decrypting the selected field of the reproduced partial encryption file with a first secret key corresponding to the first public key to reproduce the personal data file. The encryption method according to claim 1, wherein the encryption method is provided. 3. The selecting step selects the field stepwise according to a plurality of stepwise standards as the predetermined standard, and the partial encryption step selects the stepwise selected field for each step. The encryption method according to claim 1, wherein encryption is performed with a different first public key. 4. A part for decrypting the stepwise selected field of the partially encrypted file reproduced by the full decryption step with a first secret key corresponding to a first public key that differs at each stage. The encryption method according to claim 3, further comprising a decryption step. 5. The whole encryption step includes a step of encrypting the partially encrypted file with a common key, and a second step of using the common key.
Encrypting with a public key, the whole decrypting step includes a step of decrypting the common key with a second secret key corresponding to the second public key, and a step of decrypting the common key with the decrypted common key. The method according to any one of claims 1 to 4, further comprising the step of decrypting the entire encrypted file. 6. The whole encryption step encrypts the partially encrypted file with a second public key, and the whole decryption step includes a second public key corresponding to the second public key.
The encryption method according to any one of claims 1 to 4, wherein the entire encrypted file is decrypted with a secret key. 7. The method further comprises the step of assigning to the partially encrypted file a record identifier different from the individual ID code for each of the individual records, wherein the partial encryption step is based on the record identifier. 7. The encryption method according to any one of claims 1 to 6, wherein the selected field is encrypted so that the statistical processing or the analysis processing of can be performed. 8. A personal data file comprising at least one personal record consisting of a plurality of fields in which a predetermined unit of personal data is coded, digitized or textified for each item in a uniform format according to a predetermined standard. Selection means for selecting a field corresponding to an item that can identify an individual, and a partially encrypted file in which the selected field is encrypted with a first public key and the fields not selected by the selection means are not encrypted A partial encryption unit for creating a partial encryption file, an entire encryption unit for encrypting the created partial encryption file to create an entire encrypted file, and a partial encryption unit for decrypting the created entire encryption file An encryption system comprising an entire decryption means for reproducing a file. 9. A partial decryption means for decrypting the selected field of the reproduced partial encryption file with a first secret key corresponding to the first public key to reproduce the personal data file. The encryption system according to claim 8, further comprising: 10. The selecting means selects the field stepwise according to a plurality of stepwise standards as the predetermined standard, and the partial encryption means selects the field selected stepwise for each step. 9. The encryption system according to claim 8, wherein encryption is performed with a different first public key. 11. A first public key corresponding to a first public key, which is different in each step, in the field selected in steps in the partially encrypted file reproduced by the full decryption means.
The encryption system according to claim 10, further comprising a partial decryption unit that decrypts with a secret key. 12. The full encryption means includes means for encrypting the partially encrypted file with a common key, and means for encrypting the common key with a second public key. , And a means for decrypting the common key with a second secret key corresponding to the second public key, and a means for decrypting the whole encrypted file with the decrypted common key. The cryptographic system according to any one of Items 8 to 11. 13. The full encryption means encrypts the partially encrypted file with a second public key, and the full decryption means includes a second public key corresponding to the second public key.
The encryption system according to any one of claims 8 to 11, wherein the entire encrypted file is decrypted with a secret key. 14. The partial encryption file further includes means for assigning a record identifier different from a personal ID code to each of the individual records, wherein the partial encryption means is based on the record identifier. 14. The cryptographic system according to claim 8, wherein the selected field is encrypted so that the statistical processing or the analysis processing of the above can be performed. 15. A personal data file comprising at least one personal record consisting of a plurality of fields in which a predetermined unit of personal data is coded, digitized or textified for each item in a uniform format according to a predetermined standard. Selection means for selecting a field corresponding to an item that can identify an individual, and a partially encrypted file in which the selected field is encrypted with the first public key and the fields not selected by the selection means are not encrypted An encryption device comprising: a partial encryption means for creating a whole encrypted file by encrypting the created partial encrypted file. 16. A decryption device comprising an overall decryption means for decrypting the entire encrypted file created by the encrypting device according to claim 15 and reproducing the partial encrypted file. 17. A partial decryption means for decrypting the selected field of the reproduced partial encryption file with a first secret key corresponding to the first public key to reproduce the personal data file. The decoding device according to claim 16, further comprising: 18. A computer program that causes a computer to function as the cryptographic system according to claim 8. 19. A computer program causing a computer to function as the encryption device according to claim 15. 20. A computer program causing a computer to function as the decoding device according to claim 16 or 17.