KR102409666B1 - Method of tracing suspected infectee based on card payment data without privacy breaches using functional encryption techniques - Google Patents

Abstract

A method for tracking a suspected infection is disclosed. The method for tracking a suspected infection is performed in a computing device including at least a processor, receiving encrypted personal information using an inner product encryption technique, receiving identification information of an infected person and a time threshold and determining a suspected infection using the encrypted personal information, the identification information of the infected person, and the time threshold, wherein the encrypted personal information includes identification information of a payer of card payment; It is generated by encrypting payment information including the place where the card payment was made and the time when the card payment was made, and the time threshold means the survival time of the virus or bacteria possessed by the infected person.

Description

A method of tracking an infectious disease based on card payment history that does not cause harm to privacy using function encryption technology

The present invention relates to a method for tracking a suspected infection, and more particularly, to a method for tracking a suspected infection based on card payment history data so that privacy is not infringed using functional encryption technology.

Since Corona 19 (COVID-19) is a new pandemic infectious disease for which there is no preventive vaccine and appropriate treatment, non-pharmaceutical interventions are used to counter the outbreak of infectious diseases and the spread of the virus. In many countries, including Korea, where the COVID-19 outbreak occurred on a large scale, quarantine and close contact tracing have been selected as public health measures. Since COVID-19 is contagious before symptoms appear, we use a strategy to reduce the number of initial cases and reduce the overall size of the outbreak by isolating confirmed patients and tracing the movement of close contacts.

A growing number of countries are also cautiously utilizing digital tracking devices that rely on the automatic generation of location data for rapid tracking. In some cases, the collected data will be disclosed to the general public or other contacts, raising concerns about privacy. Recently, while solving the problem of privacy protection, applications using Bluetooth technology that can perform large-scale tracking are also being developed. Applications for tracking close contacts say that 'personal information protection technology' is applied, but concerns about personal information infringement still persist.

Korean Patent Application Publication No. 10-2017-0053145 (published on May 15, 2017)

The problem to be solved by the present invention is to provide a method for tracking a suspected infection that protects personal information and determines a suspected infection without violating privacy. In addition, it is revealed that the present invention is the research result of the 'data-based system to prevent infectious diseases without invasion of privacy' project (task number: 2020K2A9A1A01095894) of the 'research exchange support project (general)' of the National Research Foundation of Korea.

A method for tracking a suspected infection according to an embodiment of the present invention is performed in a computing device including at least a processor, and includes the steps of receiving encrypted personal information using an inner product encryption technique, identification information of the infected person and Receiving a time threshold, and determining a suspected infection using the encrypted personal information, the identification information of the infected person, and the time threshold, wherein the encrypted personal information is card payment ) is generated by encrypting payment information including the identification information of the payer, the place where the card payment was made, and the time when the card payment was made, and the time threshold means the survival time of the virus or bacteria possessed by the infected person.

In the case of the method for tracking a suspected infection according to the embodiments of the present invention, data such as card payment details can be distributed without infringing privacy by internally encrypting personal information.

In addition, there is an effect of finding a suspected infection based on the card payment history without invading privacy.

In addition, it is possible to utilize and distribute various data because it can be applied to situations where it is necessary to know whether the data matches or the difference in values as well as tracking suspected infections.

In order to more fully understand the drawings recited in the Detailed Description, a detailed description of each drawing is provided.
1 is a schematic diagram for explaining a method for tracking a suspected infection according to an embodiment of the present invention.
2 is a flowchart illustrating a method for tracking a suspected infection according to an embodiment of the present invention.

Specific structural or functional descriptions of the embodiments according to the concept of the present invention disclosed herein are only exemplified for the purpose of explaining the embodiments according to the concept of the present invention, and the embodiment according to the concept of the present invention These may be embodied in various forms and are not limited to the embodiments described herein.

Since the embodiments according to the concept of the present invention may have various changes and may have various forms, the embodiments will be illustrated in the drawings and described in detail herein. However, this is not intended to limit the embodiments according to the concept of the present invention to specific disclosed forms, and includes all modifications, equivalents, or substitutes included in the spirit and scope of the present invention.

Terms such as first or second may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another, for example without departing from the scope of the inventive concept, a first component may be termed a second component and similarly a second component A component may also be referred to as a first component.

When a component is referred to as being “connected” or “connected” to another component, it is understood that it may be directly connected or connected to the other component, but other components may exist in between. it should be On the other hand, when it is said that a certain element is "directly connected" or "directly connected" to another element, it should be understood that the other element does not exist in the middle. Other expressions describing the relationship between components, such as "between" and "immediately between" or "neighboring to" and "directly adjacent to", etc., should be interpreted similarly.

The terms used herein are used only to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In this specification, terms such as "comprise" or "have" are intended to designate that a feature, number, step, operation, component, part, or combination thereof described herein exists, but one or more other features It should be understood that it does not preclude the possibility of the presence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present specification. does not

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the scope of the patent application is not limited or limited by these embodiments. Like reference numerals in each figure indicate like elements.

1 is a schematic diagram for explaining a method for tracking a suspected infection according to an embodiment of the present invention, and FIG. 2 is a flowchart for explaining a method for tracking a suspected infection according to an embodiment of the present invention. The method for tracing a suspected infection or an infectious disease tracing method detailed below may be performed by at least one computing device including at least a processor and/or a memory, for example, a PC, a laptop computer, a notebook computer, a server, and the like. For example, each step of the proposed method may be viewed as an operation of a processor included in a computing device. Also, each step may be performed by different computing devices. For example, the operation of encrypting the payment details using a function password and transmitting the encrypted payment details may be performed in a computing device operated by a card company or a person (or company) entrusted with the card company, and the identification information of the infected person and The operation of extracting and/or determining the time threshold and transmitting the time threshold may be performed by another computing device (eg, a computing device operated by a government agency or a person commissioned by a government agency or a company).

1 and 2 , a database may be formed by encrypting personal information using a functional encryption technique (S100). According to an embodiment, the personal information is information about card payment details, and may include at least one of identification information (ID), location information (Location), and time information (Visit Time). The identification information ID may refer to information capable of identifying card payment details, information capable of identifying a card payer, or information capable of identifying a card holder. Location information may mean at least one of location or identification information of a card affiliated store where card payment is made, and location information (eg, GPS coordinates) of a card payer or holder. The time information (Visit Time) may mean a time when card payment is made. In addition, personal information may be encrypted using inner product encryption among function encryption techniques. Hereinafter, the inner cryptography will be described.

The inner encryption is a setup algorithm represented by Algorithm 1 (setup step or setup process), a key generation algorithm represented by Algorithm 2 (key generation step or key generation process), and an encryption algorithm represented by Algorithm 3 (encryption step or encryption process). ) is composed of

, 소수(prime number)

, 및

를 위수로 갖는 2개의 상이한 순환군들(cyclic groups)

를 입력으로 받고, 마스터 비밀키(master secret key)

를 출력한다. 알고리즘 1의 구체적인 내용은 아래와 같다.Algorithm 1 is Vector size

, prime number

, and

two different cyclic groups with the order of

as input, and the master secret key

to output The details of Algorithm 1 are as follows.

[Algorithm 1]

, 평문(plaintext)

, 및 소수

를 입력으로 받고, 비밀키(Secret key)

를 출력한다. 알고리즘 2의 구체적인 내용은 아래와 같다.Algorithm 2 is the master secret key

, plaintext

, and decimal

receive as input, and the secret key

to output The details of Algorithm 2 are as follows.

[Algorithm 2]

, 평문(plaintext)

, 및 소수

를 입력으로 받고, 암호문(Ciphertext)

를 출력한다. 알고리즘 3의 구체적인 내용은 아래와 같다.Algorithm 3 is the master secret key

, plaintext

, and decimal

as input, and ciphertext

to output The details of Algorithm 3 are as follows.

[Algorithm 3]

As such, the encryption operation using the function encryption technique is performed by a computing device (eg, a server including at least a processor and/or memory) operated by the card company directly or entrusted, and the encrypted card payment history data requires it It may be transmitted to a computing device operated by an institution or a user directly or by entrusted operation.

As described above, since the card payment history data is encrypted using a function encryption technique, the card payment history data can be distributed without a problem of invasion of privacy, and based on the distributed data, a person suspected of being infected with an infectious disease can be identified as an invasion of privacy. You can check it without any problem.

Based on the database, the suspected infection can be tracked using the information of the infected person. In this specification, a query for a suspected infection using the ID of the confirmed infected person is referred to as a privacy preserving contact tracing (PPCT) query.

Specifically, by sending a PPCT query to the database (S200), the suspects who have visited the same place as the confirmed infected person are identified (S300), and among the confirmed suspects, the suspects who visited adjacent to the visit time of the confirmed infected person are infected It can be determined as a suspect (S400). The PPCT query result can be delivered to the suspected infection (S500).

That is, the computing device performing the PPCT query receives the infected person identification information (Infected ID) and/or threshold time information through wired/wireless communication or a predetermined input interface, and stores the encrypted payment details included in the storage device of the computing device. It can be used to search or track suspected infections. Here, the infected person identification information is information that can identify the infected person, and may mean an ID for identifying the infected person's payment details from among the payment details. In addition, the critical time information may mean a survival time of a virus and/or bacteria infected by an infected person.

After the identification information of the infected person and the critical time information are received, a payment price that has visited the same place as the infected person or made a payment at the same place may be searched. Then, by calculating the infection probability of each payer, it is possible to extract a suspected infection. For example, a payment price having an infection probability greater than 0 may become a suspected infection.

Specifically, a suspected infection may be determined using a PPCT query according to the following algorithms 4 to 6.

A method for tracking an infectious disease (or a method for tracking a suspected infection) according to an embodiment of the present invention will be described in more detail.

, 감염자들(infected persons)의 집합

, 및 시간 임계치(time threshold)

가 주어졌을 때, 감염 확률(infection probability)

가 0보다 큰 사람들(또는 결제자)의 집합

을 검색할 수 있다. 장소

에서 감염자

로부터 결제자

가 감염될 확률, 즉 감염 확률은 수학식 1에 의해 정의된다.encrypted trajectories

, the set of infected persons

, and a time threshold

Given a, infection probability

set of people (or payers) where is greater than 0

can be searched for. Place

infected in

payer from

The probability of being infected, that is, the probability of infection, is defined by Equation 1.

[Equation 1]

The specific operation of the infectious disease tracking method is described in detail in Algorithm 4. For efficiency, the overlap (or overlap) of places may be first checked and then the time gap calculated. Here, overlapping places may mean visiting the same place or card affiliated store, and the time difference may mean a difference between the payment time of the infected person and the payment time of the payer visiting the same place. Also, according to an embodiment, the overlap of places may be checked after the time difference is calculated first.

1 shows a specific example of a method for tracking an infectious disease. First, card payment data is stored in an encrypted format (① in FIG. 1). The location is encrypted in decomposed form. That is, each digit is encrypted with an individual cipher-text. In the example of FIG. 1, only the alphabet is described, but the actual cipher text may be more complicated than this. It should be noted that the same place '153242' can be encrypted with a different ciphertext, since the cryptography is not deterministic.

Given the PPCT query including the IDs of the infected and the critical time threshold, the epidemic tracking algorithm is started (refer to ② in FIG. 1). Then, the algorithm searches for payers who visited the same place as the infected (see ③ in FIG. 1). In the example of FIG. 1 , it can be seen that the payers with IDs '2391' and '2013' were in the same place '153242' as the infected person '3018'.

Thereafter, the algorithm calculates the infection probability of overlapping people, that is, the infection probability of the payer who visited the same place as the infected person (see ④ in FIG. 1 ). Infected person '3018' was at location '153242' at 12:32, while payer '2391' was at the same place at 19:45. Thus, the time difference between the two is greater than the time threshold (ie 60 minutes) (ie probability of infection = 0). Payer '2013' was at location '563421' at 16:31, and infected person '3018' was at the same place at 17:11. Because the time difference between two people is less than 60 minutes, the probability of infection between two people is 1/3. If the payer '2013' and the infected person '3018' visit '563421' several times, the infection probability will be added up. Obviously, the time and location of the visit are not disclosed in plain-text form. If the infection probability is calculated for all overlapping places, the contact list with the infection probability and the infection probability may be output (refer to ⑤ in FIG. 1 ).

In Algorithm 4 below, PPCT first finds the index of confirmed cases (lines 1-4). Then, the PPCT checks whether the payer has visited the place visited by the infected person (line 8). If the result of the decrypt function is '0', this means that the secret key and the ciphertext are the same (line 13). In order to omit the decryption operation thereafter, a place visited by the payer may be stored (line 15). The algorithm searches newLocations for payers who have contacted the infected (lines 7-19). Then, the PPCT calculates the time difference between the payer and the infected (lines 17 and 29). Finally, in oldLocations, a payer who has contacted an infected person can be searched (lines 20-31).

[Algorithm 4]

[Algorithm 5]

In Algorithm 5, an index of an infected person who has visited a place newLocation that has not yet been investigated may be stored (line 2). Then, the algorithm checks whether the location has been inspected (line 5). If the result of the decrypt function is '0', it means that the secret key and the ciphertext are the same (line 7). If the infected person has visited the location being investigated, the index is added to oldLocations (lines 8-10). If the infected person has visited a location that has not been investigated, store the index in newLocations and update the locations and oldLocations (lines 11-15).

[Algorithm 6]

As such, in terms of utilizing the database, a suspected infection can be identified by using the PPCT query in the undecrypted state.

By using the method for tracking a suspected infection according to embodiments of the present invention, it is possible to prevent invasion of privacy by epidemiological investigators, which has occurred in the past, and it is possible to distribute card payment history data without a problem of privacy violation.

In addition, since it can be applied to situations where it is necessary to know whether data is consistent or different in values, as well as tracking suspected infections, various data can be utilized and distributed.

The device described above may be implemented as a hardware component, a software component, and/or a set of hardware components and software components. For example, the devices and components described in the embodiments may include, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable array (FPA), It may be implemented using one or more general purpose or special purpose computers, such as a Programmable Logic Unit (PLU), a microprocessor, or any other device capable of executing and responding to instructions. The processing device may execute an operating system (OS) and one or more software applications executed on the operating system. A processing device may also access, store, manipulate, process, and generate data in response to execution of the software. For convenience of understanding, although one processing device is sometimes described as being used, one of ordinary skill in the art will recognize that the processing device includes a plurality of processing elements and/or a plurality of types of processing elements. It can be seen that can include For example, the processing device may include a plurality of processors or one processor and one controller. Other Processing Configurations are also possible, such as a Parallel Processor.

The software may include a computer program, code, instructions, or a combination of one or more thereof, and configure the processing device to operate as desired or independently or collectively processed You can command the device. The software and/or data may be any type of machine, component, physical device, virtual equipment, computer storage medium or device, to be interpreted by or provide instructions or data to the processing device. , or may be permanently or temporarily embodied in a transmitted signal wave (Signal Wave). The software may be distributed over networked computer systems and stored or executed in a distributed manner. Software and data may be stored in one or more computer-readable recording media.

The method according to the embodiment may be implemented in the form of program instructions that can be executed through various computer means and recorded in a computer-readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or preferably. The program instructions recorded on the medium may be specially designed and configured for the embodiment, or may be known and available to those skilled in the art of computer software. Examples of the computer-readable recording medium include magnetic media such as hard disks, floppy disks and magnetic tapes, optical recording media such as CD-ROMs and DVDs, and magnetic such as floppy disks. - Includes hardware devices specially configured to store and execute program instructions, such as Magneto-optical Media, ROM, RAM, Flash memory, and the like. Examples of program instructions include not only machine language codes such as those generated by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

Although the present invention has been described with reference to the embodiment shown in the drawings, which is only exemplary, those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. For example, the described techniques are performed in an order different from the described method, and/or the described components of the system, structure, apparatus, circuit, etc. are combined or combined in a different form than the described method, or other components Or substituted or substituted by equivalents may achieve an appropriate result. Accordingly, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

Claims (6)

In the method for tracking a suspected infection performed in a computing device including at least a processor,
Receiving encrypted personal information using an inner product encryption (Inner Product Encryption) technique;
receiving identification information of an infected person and a time threshold; and
determining a suspected infection using the encrypted personal information, the identification information of the infected person, and the time threshold,
The encrypted personal information is generated by encrypting payment information including identification information of a payer of a card payment, a place where the card payment is made, and a time when the card payment is made,
The time threshold means the survival time of the virus or bacteria possessed by the infected person,
The step of determining the suspected infection is,
searching for a payer who has visited a place visited by the infected person; and
Comprising the step of calculating the infection probability of the payer who visited the place visited by the infected person,
The infection probability is defined by Equation 1,
Equation 1 is

ego,
remind

a place

infected in

payer from

means the probability of being infected,
remind

means a time threshold,
How to track a suspected infection. delete delete According to claim 1,
In the step of determining the suspected infection, a payer having an infection probability greater than '0' is determined as a suspected infection,
How to track a suspected infection. delete delete

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