Method, system, electronic device and storage medium for obtaining intersection of private data

Abstract

The present application relates to a method, system, electronic device and storage medium for obtaining the intersection of private data, wherein the method for obtaining the intersection of private data includes: the initiator sends the encrypted initiator's itinerary information to at least one receiver, and the receiver encrypts the itinerary encryption parameters and the receiver's itinerary information respectively; through homomorphic encryption calculation, the receiver determines the size comparison result based on the encrypted initiator's itinerary information and the encrypted receiver's itinerary information, and obtains the itinerary comparison information in an encrypted state based on the size comparison result and the encrypted itinerary information encryption parameters; the initiator determines whether there is a data intersection between the initiator and the receiver based on the numerical parameters of the decrypted itinerary comparison information. Through this application, the problem of finding close contacts by publishing the patient's itinerary information in the related technology, which leads to the leakage of the patient's personal privacy data, is solved, and the patient's privacy is protected.

Description

Technical Field

[0001] The present application relates to the field of data processing technology, and in particular to a method, system, electronic device and storage medium for obtaining intersections of privacy data. Background Art

[0002] In order to curb the development of the epidemic caused by the virus, it is often necessary to release the real-time progress of the epidemic in a timely manner, such as the number of confirmed cases and suspected cases per day, and then adjust the prevention and control measures in a timely manner according to the real-time progress of the epidemic. Specifically, once a confirmed patient is found, it is necessary to determine the patient's travel trajectory as soon as possible in order to quickly find close contacts, so as to quickly block the spread of the epidemic.

[0003] In the related art, in order to quickly locate the patient, it is necessary to ask the patient's travel information and publish the patient's travel information so that close contacts can actively report. Although the above method can achieve rapid positioning, it exposes the patient's personal privacy data.

[0004] There is currently no effective solution to the problem of related technologies that use the publication of patients' travel information to find close contacts, leading to the leakage of patients' personal privacy data. Summary of the invention

[0005] In this embodiment, a method, system, electronic device and storage medium for obtaining the intersection of privacy data are provided to solve the problem in the related art of finding close contacts by publishing the patient's travel information, which leads to the leakage of the patient's personal privacy data.

[0006] In a first aspect, a method for obtaining an intersection of private data is provided in this embodiment, including:

[0007] The initiator sends the encrypted itinerary information of the initiator to at least one receiver, and the receiver encrypts the itinerary encryption parameter and the itinerary information of the receiver respectively;

[0008] Through homomorphic encryption calculation, the receiver determines the size comparison result according to the encrypted itinerary information of the initiator and the encrypted itinerary information of the receiver, and obtains the itinerary comparison information in an encrypted state according to the size comparison result and the encryption parameter of the encrypted itinerary information;

[0009] The initiator determines whether there is data intersection between the initiator and the receiver according to the numerical parameters of the decrypted trip comparison information.

[0010] In some embodiments, when the recipient's itinerary information includes the recipient's arrival itinerary information and the recipient's departure itinerary information, the recipient determines the size comparison result according to the encrypted initiator's itinerary information and the encrypted recipient's itinerary information through homomorphic encryption calculation, and obtains the itinerary comparison information in an encrypted state according to the size comparison result and the encrypted itinerary information encryption parameter, including:

[0011] The receiver determines a size comparison result between the encrypted receiver's arrival itinerary information and the encrypted initiator's itinerary information, and obtains first comparison information in an encrypted state according to the size comparison result and a first encryption parameter;

[0012] The receiver determines a size comparison result between the encrypted receiver's departure trip information and the encrypted initiator's trip information, and obtains second comparison information in an encrypted state according to the size comparison result and a second encryption parameter.

[0013] In some embodiments, the initiator determines whether there is data intersection between the initiator and the receiver according to the numerical parameters of the decrypted trip comparison information, including:

[0014] The initiator determines whether there is data intersection between the initiator and the receiver according to the number of digits and / or the number signs of the first comparison information and the second comparison information.

[0015] In some embodiments, the initiator's travel information and the receiver's travel information both include time information, and the initiator determines whether there is data intersection between the initiator and the receiver based on the number of digits and / or numerical symbols of the first comparison information and the second comparison information, including:

[0016] In a case where the number of digits of the first comparison information and the second comparison information is greater than the number of digits of the digit corresponding to the time information, the initiator determines that there is no data intersection;

[0017] When the number of numerical digits of the first comparison information and the second comparison information is less than or equal to the number of numerical digits corresponding to the time information, the initiator determines whether there is data intersection between the initiator and the receiver based on the numerical signs of the first comparison information and the second comparison information.

[0018] In some embodiments, before the initiator sends the encrypted initiator trip information to at least one recipient, the method includes:

[0019] In the case that the initial trip information of the initiator includes a time period, the initiator converts the initial trip information into a plurality of discrete initiator trip information.

[0020] In some embodiments, the initiator converting the initial trip information into a plurality of discrete initiator trip information comprises:

[0021] The initiator expands the initial trip information into a plurality of discrete trip information of the initiator according to a preset time accuracy; or,

[0022] The initiator determines the initiator's arrival itinerary information and the initiator's departure itinerary information at each location according to the time information and the location information in the initial itinerary information, and uses the initiator's arrival itinerary information and the initiator's departure itinerary information as the initiator's itinerary information.

[0023] In some of the embodiments, before the initiator sends the encrypted initiator trip information to at least one recipient, the method further includes:

[0024] The initiator concatenates the location information in the initial itinerary information of the initiator with the corresponding time information of the initiator in a numerical format to obtain the itinerary information of the initiator; and / or,

[0025] The receiver concatenates the location information in the receiver's initial itinerary information with the receiver's time information in a corresponding numerical format to obtain the receiver's itinerary information.

[0026] In some embodiments, after the initiator determines whether there is data intersection between the initiator and the receiver based on the numerical parameters of the decrypted trip comparison information, the method includes:

[0027] If the initiator and the receiver have data intersection, the initiator sends notification information to the receiver.

[0028] In some of the embodiments, the initiator records the travel information of the initiator according to its own movement trajectory; and / or the recipient records the travel information of the recipient according to its own movement trajectory.

[0029] In a second aspect, a system for obtaining the intersection of private data is provided in this embodiment, including an initiator and at least one receiver:

[0030] The initiator sends the encrypted itinerary information of the initiator to at least one receiver, and the receiver encrypts the itinerary encryption parameter and the itinerary information of the receiver respectively;

[0031] Through homomorphic encryption calculation, the receiver determines the size comparison result according to the encrypted itinerary information of the initiator and the encrypted itinerary information of the receiver, and obtains the itinerary comparison information in an encrypted state according to the size comparison result and the encryption parameter of the encrypted itinerary information;

[0032] The initiator determines whether there is data intersection between the initiator and the receiver according to the numerical parameters of the decrypted trip comparison information.

[0033] In a third aspect, an electronic device is provided in this embodiment, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the method for obtaining the intersection of privacy data described in the first aspect is implemented.

[0034] In a fourth aspect, a storage medium is provided in this embodiment, on which a computer program is stored, and when the program is executed by a processor, the steps of the method for obtaining the intersection of privacy data described in the first aspect are implemented.

[0035] Compared with the related art, the method for obtaining the intersection of private data provided in this embodiment is that the initiator sends the encrypted initiator's itinerary information to at least one receiver, and the receiver encrypts the itinerary encryption parameters and the receiver's itinerary information respectively; through homomorphic encryption calculation, the receiver determines the size comparison result based on the encrypted initiator's itinerary information and the encrypted receiver's itinerary information, and obtains the itinerary comparison information in an encrypted state based on the size comparison result and the encrypted itinerary information encryption parameters; the initiator determines whether there is a data intersection between the initiator and the receiver based on the numerical parameters of the decrypted itinerary comparison information. Based on the homomorphic encryption process, the initiator performs privacy intersection calculation on different itinerary information, which solves the problem of finding close contacts by publishing the patient's itinerary information in the related art, resulting in the leakage of the patient's personal privacy data, and protects the patient's privacy.

[0036] Details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more readily apparent. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0038] Figure 1 It is a schematic diagram of the application environment of the method for obtaining the intersection of privacy data according to an embodiment of the present application.

[0039] Figure 2It is a flowchart of a method for obtaining the intersection of privacy data according to an embodiment of the present application.

[0040] Figure 3 It is a schematic diagram of privacy intersection according to an embodiment of the present application.

[0041] Figure 4 It is a flowchart of another method for obtaining the intersection of privacy data according to an embodiment of the present application.

[0042] Figure 5 It is a flowchart of a data intersection determination method according to an embodiment of the present application.

[0043] Figure 6 This is a flowchart of another method for obtaining the intersection of privacy data according to an embodiment of the present application.

[0044] Figure 7 It is a structural block diagram of a system for obtaining the intersection of privacy data according to an embodiment of the present application. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0046] During the development of the epidemic, once a patient is diagnosed, it is necessary to find the patient's travel trajectory as soon as possible in order to quickly find close contacts and quickly block the spread of the epidemic. However, in the current process of obtaining travel information, the patient's location information is difficult to quickly locate, so it is necessary to ask the patient's travel information and publish the information. The above method may have omissions in personal memory, so the accuracy is low. Moreover, publishing the patient's travel information will leak personal privacy and is less secure.

[0047] The method for obtaining the intersection of private data provided in the embodiment of the present application can be applied to Figure 1 In the application environment shown, Figure 1 is a schematic diagram of an application environment of a method for obtaining a privacy data intersection according to an embodiment of the present application, such as Figure 1As shown, the initiator 102 communicates with the receiver 104 through the network. Both the initiator 102 and the receiver 104 may have a data storage system to store the data to be processed. The initiator 102 sends the encrypted initiator's itinerary information to at least one receiver 104; the receiver 104 determines the size comparison result based on the encrypted receiver's itinerary information and the initiator's itinerary information, and obtains the itinerary comparison information in the encrypted state based on the size comparison result and the itinerary information encryption parameter; the initiator 102 determines whether there is data intersection between the initiator 102 and the receiver 104 based on the numerical parameters of the decrypted itinerary comparison information. Among them, the initiator 102 and the receiver 104 can be, but are not limited to, various portable laptops, smart phones, tablets and portable wearable devices, and the portable wearable devices can be smart watches, smart bracelets, head-mounted devices, etc.

[0048] In this embodiment, a method for obtaining the intersection of private data is provided to determine whether the target population and the patient's itinerary have an intersection, wherein the target population can be a population within a certain time period in the target area defined according to demand. Whether the itinerary of the target population and the patient intersects needs to be determined based on their respective itinerary information. The itinerary information is the itinerary trajectory of the patient or each person in the target population, recording their specific location at a certain moment, including time information and location information. The initiator's itinerary information, the recipient's itinerary information, the recipient's arrival itinerary information, the recipient's departure itinerary information, the initial itinerary information, etc. in this application are all itinerary information under different circumstances.

[0049] Figure 2 is a flow chart of the method for obtaining the intersection of private data in this embodiment. Figure 2 As shown, the process includes the following steps:

[0050] In step S201, the initiator sends the encrypted itinerary information of the initiator to at least one receiver, and the receiver encrypts the itinerary encryption parameters and the itinerary information of the receiver respectively.

[0051] Usually, after being diagnosed, the patient can initiate the intersection calculation process of private data as the initiator. In order to avoid privacy leakage, the initiator needs to encrypt its own initiator travel information first, and then send the encrypted initiator travel information to the receiver. Among them, the initiator travel information can be travel information within a certain time period, or it can be travel information at a certain time point. The time point or time period is determined according to the preset time accuracy. For example, if the preset time accuracy is day, then [Hangzhou, October 8, October 10] is the travel information of a time period, and [Hangzhou, October 9] is the travel information of a time point. If the preset time accuracy is hour, then [Hangzhou, October 8 10:00, October 10 14:00] is the travel information of a time period, and [Hangzhou, October 9 11:00] is the travel information of a time point.

[0052] Specifically, when homomorphic encryption is used, the initiator can first generate a public-private key pair, and then encrypt the initiator's itinerary information according to the public key in the public-private key pair, and send the public key to the receiver at the same time as sending the initiator's itinerary information. The initiator's itinerary information is the itinerary information belonging to the initiator, and the number of receivers is determined according to the number of target groups. At this time, the target group can be all people who can perform private data intersection calculations, or people who can perform private data intersection calculations in a certain area.

[0053] The recipient's itinerary information is the itinerary information belonging to the recipient, and the process of the recipient encrypting the itinerary encryption parameters and the recipient's itinerary information can also be achieved through the initiator's public key.

[0054] Step S202, through homomorphic encryption calculation, the receiver determines the size comparison result according to the encrypted itinerary information of the initiator and the encrypted itinerary information of the receiver, and obtains the itinerary comparison information in an encrypted state according to the size comparison result and the encryption parameter of the encrypted itinerary information.

[0055] During the calculation of the intersection of private data, the time accuracy of the receiver must be consistent with that of the initiator. If the time accuracy of both parties is inconsistent when recording the itinerary information, the time unit with higher accuracy needs to be converted to the time unit with lower accuracy during the calculation. For example, when recording the itinerary information, the initiator uses days as the unit and the receiver uses hours as the unit. In the calculation of the intersection of private data, the receiver needs to convert the time information in the itinerary information to obtain the receiver's itinerary information in days.

[0056] Specifically, the size comparison result of the itinerary information of the receiver and the itinerary information of the initiator can be achieved by subtracting the difference. If both parties compare the size through the itinerary information at a time point, the difference between the itinerary information of the initiator and the itinerary information of the receiver can be directly obtained; if one party has the itinerary information at a time point and the other party has the itinerary information of a time period, the itinerary information of multiple time points is determined in the itinerary information of the time period, and then the difference between the itinerary information of the two parties at different time points is calculated. It should be noted that the size comparison result obtained by homomorphic encryption calculation is also in an encrypted state.

[0057] Furthermore, in order to prevent the initiator from obtaining the real itinerary information of the receiver, the receiver needs to encrypt the size comparison result again by using the itinerary encryption parameter after calculating the size comparison result to obtain the itinerary comparison information in an encrypted state. The itinerary encryption parameter in this embodiment is a random number that is not 0 and is preferably a positive integer.

[0058] It should be noted that, according to the properties of homomorphic encryption, after subtracting or multiplying the encrypted data from the data before encryption, the properties of the calculation result remain unchanged. The homomorphic encryption in this embodiment can be full homomorphic encryption or partial homomorphic encryption.

[0059] Each itinerary information in this embodiment can be actively uploaded by the users of the initiator and the receiver, and at this time, the initiator and / or the receiver can remind the user regularly. On the other hand, the initiator and / or the receiver can also obtain the itinerary information regularly.

[0060] Step S203: The initiator determines whether there is data intersection between the initiator and the receiver based on the numerical parameters of the decrypted itinerary comparison information.

[0061] The receiver sends the encrypted itinerary comparison information to the initiator, and the initiator decrypts the encrypted itinerary comparison information according to the private key in the public-private key pair, and finally determines whether there is data intersection between the initiator and the receiver based on the numerical parameters of the decrypted itinerary comparison information.

[0062] For example, when the initiator's itinerary information and the receiver's itinerary are both time points, as long as the itinerary comparison information is not 0, there is no intersection between the initiator and the receiver.

[0063] Through the above steps S201 to S203, in the process of calculating the privacy intersection of the travel information of the initiator and the receiver, the travel intersection calculation is realized by comparing the encrypted travel information of the initiator with the travel information of the receiver. At the same time, the initiator and the receiver both perform homomorphic encryption on their respective travel information to achieve privacy protection. Therefore, the problem of finding close contacts by publishing the travel information of patients in related technologies, which leads to the leakage of patients' personal privacy data, is solved, the privacy of patients is protected, and data security is improved.

[0064] In this embodiment, although the time precision needs to be set when recording the travel information, in the process of calculating the privacy intersection data, the complexity is irrelevant to the precision of the recorded time series data, so the calculation efficiency and network transmission efficiency in this embodiment are greatly improved.

[0065] It should be noted that the method for obtaining the intersection of private data in this application can be implemented as an application software (Application) or as a system service. Among them, the private intersection refers to finding the intersection of two data sets while protecting the privacy of the non-intersection parts of both parties. Figure 3 is a schematic diagram of a privacy intersection according to an embodiment of the present application, such as Figure 3 As shown, the shaded area is the intersection part that needs to be confirmed, and the blank area is the privacy part that needs to be protected.

[0066] In some of these embodiments, Figure 4 is a flowchart of another method for obtaining the intersection of privacy data according to an embodiment of the present application. Figure 4 As shown, the process includes the following steps:

[0067] Step S401: the initiator sends the encrypted initiator's travel information to at least one recipient.

[0068] In step S402, the receiver determines a size comparison result between the encrypted receiver's arrival itinerary information and the encrypted initiator's itinerary information, and obtains first comparison information in an encrypted state according to the size comparison result and the first encryption parameter.

[0069] Step S403, the receiver determines a size comparison result between the encrypted receiver's departure itinerary information and the encrypted initiator's itinerary information, and obtains second comparison information in an encrypted state according to the size comparison result and a second encryption parameter.

[0070] In the process of calculating the intersection of private data in this embodiment, the initiator's itinerary information can be regarded as a point and the receiver's itinerary information can be regarded as a range. Therefore, the intersection calculation of private data is essentially to determine whether there is an intersection between the point and the range. Specifically, the receiver's itinerary information providing the itinerary range is determined by the receiver's arrival itinerary information and the receiver's departure itinerary information. The receiver's arrival itinerary information is determined based on the time information of the receiver's arrival at a certain location and the location information of the location. The receiver's departure itinerary information is determined based on the time information of the receiver's departure from the location and the location information of the location.

[0071] When performing calculations, the receiver needs to compare the encrypted receiver's arrival itinerary information and the receiver's departure itinerary information with the encrypted initiator's itinerary information, and then perform encryption calculations on the comparison results. Specifically, the receiver obtains a first difference based on the encrypted receiver's arrival itinerary information and the encrypted initiator's itinerary information, and then homomorphically encrypts the first difference with the encrypted first encryption parameter, calculates through the ciphertext, and obtains the first comparison information in an encrypted state; similarly, the receiver obtains the second comparison information through homomorphic encryption multiplication based on the encrypted receiver's departure itinerary information and the encrypted initiator's itinerary information, as well as the encrypted second encryption parameter. The first encryption parameter and the second encryption parameter are both itinerary encryption parameters.

[0072] In the process of calculating the difference, the itinerary information of the recipient can be subtracted from the itinerary information of the initiator, or the itinerary information of the recipient can be subtracted from the itinerary information of the initiator. Preferably, the first encryption parameter and the second encryption parameter are positive integers, and the first encryption parameter is multiplied by the first difference to achieve encryption, and the second encryption parameter is multiplied by the second difference to achieve encryption. In this embodiment, the role of the first encryption parameter and the second encryption parameter is to prevent the initiator from knowing the true itinerary information of the recipient after decrypting the first comparison information and the second comparison information.

[0073] Step S404: The initiator determines whether there is data intersection between the initiator and the receiver based on the decrypted numerical parameters of the first comparison information and the second comparison information.

[0074] The receiving party sends the first comparison information in an encrypted state and the second comparison information in an encrypted state to the initiator, and the initiator decrypts the first comparison information in an encrypted state and the second comparison information in an encrypted state according to the private key in the public-private key pair, and finally determines whether there is data intersection between the initiator and the receiving party based on the numerical parameters of the decrypted first comparison information and the second comparison information.

[0075] Through the above steps S401 to S404, in the process of exchanging itinerary information, the initiator calculates the itinerary intersection by comparing the initiator's itinerary information with the receiver's arrival itinerary information and the receiver's departure itinerary information. The initiator performs homomorphic encryption calculations on the itinerary information of each party with the receiver to achieve privacy protection. This solves the problem in related technologies of finding close contacts by publishing the patient's itinerary information, which leads to the leakage of the patient's personal privacy data, thereby protecting the patient's privacy and improving data security.

[0076] Furthermore, if there is data intersection between the initiator and the receiver, the initiator sends a notification message to the receiver to reduce the spread of the epidemic, wherein the initiator and the receiver can achieve the communication process through a local area network, a mobile network or Bluetooth.

[0077] In some of the embodiments, the initiator can record its own location information in real time, and after obtaining the system's time information, record the initiator's itinerary information according to its own moving trajectory; and / or, the receiver can also record its own location information in real time, and after obtaining the system's time information, the receiver records the receiver's itinerary information according to its own moving trajectory. Specifically, the mobile trajectory can be recorded through the Global Positioning System (GPS) or the BeiDou Navigation Satellite System (BDS). In this embodiment, the recording of itinerary information through the mobile trajectory can effectively improve the accuracy of the itinerary information.

[0078] In the process of determining whether there is data intersection between the initiator and the receiver, preferably, the initiator determines whether there is data intersection between the initiator and the receiver based on the number of digits and / or numerical signs of the first comparison information and the second comparison information, wherein the number of digits is the length of the first comparison information and the second comparison information, such as two digits, four digits or eight digits, which is related to the accuracy of the time information and the location information in the trip information, and the numerical sign is the positive or negative sign of the first comparison information and the second comparison information. Of course, in some cases, the first comparison information and the second comparison information can also be 0, with no positive or negative sign. Specifically, in this embodiment, the judgment rule can be set according to the accuracy of the location information and the time information, and then the data intersection can be determined by the number of digits and / or numerical signs of the first comparison information and the second comparison information and the judgment rule, thereby improving the accuracy of the judgment result.

[0079] In some of these embodiments, Figure 5 is a flow chart of a data intersection determination method according to an embodiment of the present application. Figure 5 As shown, the method comprises the following steps:

[0080] Step S501: When the number of digits of the first comparison information and the second comparison information is greater than the number of digits of the time information, the initiator determines that there is no data intersection.

[0081] Since the travel information includes location information and time information, the number of digits of the location information and time information can be set according to the required accuracy.

[0082] For location information, if the location information is provincial, it can be represented by a one-digit code; if the location information is municipal, it can be represented by a two-digit code; and so on. The code can be letters or numbers, or a combination of various numbers, letters or symbols to improve the degree of encryption. On the other hand, when performing privacy intersection calculations on the initiator and the receiver in a certain area, the intersection calculation can be performed directly on the name itself. For example, if the initiator appears in Hangzhou, the location information can be directly written as "Hangzhou", and the corresponding digit is two.

[0083] Correspondingly, for time information, if the accuracy is set to year, month, and day, for example, 20211009, the time information is an 8-digit value. If it is accurate to hours, it can be 2021100911, which is a 10-digit value. Similarly, it can also be accurate to minutes or seconds.

[0084] When the itinerary information includes location information and time information, the itinerary information can be expressed as "Hangzhou 20211109". Therefore, when the number of digits of the first comparison information and the second comparison information is greater than the number of digits corresponding to the time information, it means that the initiator and the receiver are not in the same area, and the initiator's itinerary data and the receiver's itinerary data for comparison do not have data intersection. If the itinerary information of the initiator and / or the receiver has multiple location information, the private data intersection calculation can be performed on the itinerary information of all location information in turn to determine whether there is data intersection between the initiator and the receiver.

[0085] Preferably, the target area may be determined first, and when the initiator and the receiver are located in the same target area, the private data intersection calculation is performed. At this time, only the private data intersection on the time information needs to be considered.

[0086] Step S502: When the number of digits of the first comparison information and the second comparison information is less than or equal to the number of digits of the time information, the initiator determines whether there is data intersection between the initiator and the receiver based on the numerical signs of the first comparison information and the second comparison information.

[0087] When the number of digits of the first comparison information and the second comparison information is less than or equal to the number of digits corresponding to the time information, it indicates that the initiator and the receiver are in the same area. On this basis, it is necessary to consider whether the initiator and the receiver appear in the area at the same time.

[0088] In this embodiment, the intersection of data is determined by the numerical sign of the first comparison information and the numerical sign of the second comparison information. It should be noted that the rule for determining whether the data has an intersection based on the numerical sign needs to be determined based on the positive and negative values ​​of the first encryption parameter and the second encryption parameter, and the comparison method when the size of the initiator's itinerary information and the recipient's itinerary information are compared.

[0089] For example, assuming that the first encryption parameter and the second encryption parameter are both positive numbers, the initiator's itinerary information is the itinerary information at a point in time, and the first comparison information is calculated by subtracting the initiator's itinerary information from the receiver's arrival itinerary information, and the second comparison information is calculated by subtracting the initiator's itinerary information from the receiver's departure itinerary information. For the initiator, when the numerical signs of the first comparison information and the second comparison information are opposite, it can be determined that there is a data intersection between the initiator and the receiver. At this time, if the initiator represents the patient, the receiver is a close contact of the patient. When the numerical signs of the first comparison information and the second comparison information are the same, it can be determined that there is no data intersection between the initiator and the receiver, and within the time corresponding to the initiator's itinerary information, the receiver has not arrived at the location corresponding to the location information in the initiator's itinerary information.

[0090] For example, assuming that the first encryption parameter and the second encryption parameter are both positive numbers, the initiator's itinerary information is the itinerary information at a time point, and the first comparison information is calculated by subtracting the recipient's arrival itinerary information from the initiator's itinerary information; and the second comparison information is calculated by subtracting the recipient's departure itinerary information from the initiator's itinerary information. For the initiator, when the numerical signs of the first comparison information and the second comparison information are opposite, it can be determined that the initiator and the recipient have data intersection; when the numerical signs of the first comparison information and the second comparison information are the same, it can be determined that the initiator and the recipient do not have data intersection.

[0091] For example, assuming that the first encryption parameter is a positive number, the second encryption parameter is a negative number, and the initiator's itinerary information is the itinerary information at a time point, when calculating the first comparison information, the recipient's arrival itinerary information is subtracted from the initiator's itinerary information; when calculating the second comparison information, the recipient's departure itinerary information is subtracted from the initiator's itinerary information. Then, for the initiator, when the numerical signs of the first comparison information and the second comparison information are the same, it can be determined that the initiator and the recipient have data intersection; when the numerical signs of the first comparison information and the second comparison information are opposite, it can be determined that there is no data intersection between the initiator and the recipient.

[0092] The influence of other numerical symbol combinations of the first encryption parameter and the second encryption parameter, and the specific situation of the difference calculation on the judgment rule is similar.

[0093] Through the above steps S501 and S502, in this embodiment, the intersection of the privacy data is judged based on the number of digits and the number sign of the first comparison information and the second comparison information, which can simplify the judgment process and improve the judgment accuracy.

[0094] In some embodiments, the initial itinerary information of the initiator is itinerary information including a time period, for example, from October 8, 2021 to October 10, 2021, in Hangzhou. At this time, the initiator needs to convert it into multiple discrete itinerary information of the initiator for storage and calculation. The discrete itinerary information of the initiator is itinerary information with only location information and time information in numerical format, for example, (Hangzhou, 20211008, 20211010).

[0095] The specific conversion method is that the initiator expands the initial itinerary information into multiple discrete initiator itinerary information according to the preset time accuracy. After that, the receiver needs to perform privacy intersection calculation with each initiator itinerary information in turn to improve the accuracy of the privacy intersection calculation. Among them, the preset time accuracy is preferably various time units, such as days, hours, and minutes. The process of expanding the initial itinerary information according to the preset time accuracy is specifically to take the most forward time information in the initiator's initial itinerary information as the starting point, and take the preset time accuracy as the step length to list all the itinerary information. For example, the preset time accuracy is days, the initiator's initial itinerary information is [Hangzhou, October 8, October 10], and after expansion, it is [Hangzhou, 20211008, 20211009, 20211010].

[0096] Alternatively, the initiator determines the initiator's arrival itinerary information and the initiator's departure itinerary information at each location based on the time information and location information in the initial itinerary information, and uses the initiator's arrival itinerary information and the initiator's departure itinerary information as the initiator's itinerary information. After that, the receiver only needs to perform privacy intersection calculations with the initiator's arrival itinerary information and the initiator's departure itinerary information, respectively, to improve calculation efficiency, save storage space, reduce memory consumption, and reduce calculation complexity. Furthermore, in the process of determining the initiator's arrival itinerary information and the initiator's departure itinerary information, it is also necessary to refer to the preset time accuracy. For example, in days, the initiator's initial itinerary information is [Hangzhou, October 8, October 10], which is expanded to [Hangzhou, 20211008, 20211010], where Hangzhou is the location information, 20211008 is the initiator's starting itinerary information, and 20211010 is the initiator's ending itinerary information.

[0097] In some of these embodiments, Figure 6 is a flowchart of another method for obtaining the intersection of privacy data in this embodiment. Figure 6As shown, the process includes the following steps:

[0098] Step S601: The initiator sends the encrypted arrival itinerary information of the initiator and the encrypted departure itinerary information of the initiator to at least one receiver.

[0099] Specifically, the encryption process can be implemented by a public key, and the public key can be sent to the receiver together. The initiator's arrival trip information is determined according to the time information of the initiator's arrival at a certain location and the location information of the location, and the initiator's departure trip information is determined according to the time information of the initiator's departure from the location and the location information of the location.

[0100] Step S602, the receiver determines a size comparison result between the encrypted receiver's itinerary information and the encrypted initiator's arrival itinerary information, and obtains first comparison information in an encrypted state according to the size comparison result and the first encryption parameter.

[0101] Step S603, the receiver determines a size comparison result between the encrypted receiver's itinerary information and the encrypted initiator's departure itinerary information, and obtains second comparison information in an encrypted state according to the size comparison result and a second encryption parameter.

[0102] In the process of calculating the intersection of private data in this embodiment, the initiator's itinerary information can be regarded as the itinerary information of the time period determined by the initiator's arrival itinerary information and the initiator's departure itinerary information, and the recipient's itinerary information can be regarded as the itinerary information at a time point. Therefore, the intersection calculation of private data is essentially still to determine whether there is an intersection between the point and the range. Specifically, the initiator's arrival itinerary information is determined based on the time information of the initiator's arrival at a certain location and the location information of the location, and the initiator's departure itinerary information is determined based on the time information of the initiator's departure from the location and the location information of the location.

[0103] The process of comparing the size of the trip information and performing homomorphic encryption calculations is similar to step S402 and step S403 and will not be described in detail.

[0104] Step S604: The initiator determines whether there is data intersection between the initiator and the receiver based on the decrypted numerical parameters of the first comparison information and the second comparison information.

[0105] Through the above steps S601 to S604, this embodiment provides a method for calculating the intersection of travel information privacy data when the initiator provides the travel information of a time period and the recipient provides the travel information of a time point. It also solves the problem in the related art of finding close contacts by publishing the patient's travel information, which leads to the leakage of the patient's personal privacy data, protects the patient's privacy, and improves data security.

[0106] In some of the embodiments, the travel information is obtained by combining the location information and the time information.

[0107] For the initiator, the initiator concatenates the location information in the initial itinerary information of the initiator with the corresponding time information of the initiator in a numerical format to obtain the itinerary information of the initiator; the receiver concatenates the location information in the initial itinerary information of the receiver with the corresponding time information of the receiver in a numerical format to obtain the itinerary information of the receiver. For example, when the initial itinerary information of the initiator or the receiver is [Hangzhou, October 9] or [Hangzhou, 20211009], the itinerary information obtained after concatenation is "Hangzhou 20211009".

[0108] On the other hand, taking the receiver as an example, if the receiver has multiple itinerary information, all the itinerary information needs to be spliced. Specifically, the receiver splices the location information in the receiver's initial itinerary information with the receiver's first time information in numerical format to obtain the receiver's arrival itinerary information, and splices the receiver's second time information in numerical format with the location information to obtain the receiver's departure itinerary information, wherein the receiver's first time information is determined according to the time of arrival at the location corresponding to the location information, and the receiver's second time information is determined according to the time of leaving the location. For example, the receiver arrives in Hangzhou on October 8 and leaves Hangzhou on October 10. The receiver's initial itinerary information is [Hangzhou, October 8, October 10] or [Hangzhou, 20211008, 20211010]. The receiver's arrival itinerary information obtained after splicing can be "Hangzhou 20211008", and the receiver's departure itinerary information is "Hangzhou 20211010".

[0109] In the above splicing process, "Hangzhou" can also be replaced by numbers, letters or special symbols and their combinations. The time information in numerical format is to arrange the numerical values ​​representing the time at each time precision in order according to a certain time precision to simplify the calculation process.

[0110] The present embodiment is described and illustrated below through preferred embodiments.

[0111] Step 1: In order to save space, each client stores travel information in discrete data, such as [20211008, 20211010, Hangzhou], which means that the user corresponding to the client entered Hangzhou on October 8, 2021 and left Hangzhou on October 10, 2021;

[0112] Step 2, each client concatenates the itinerary information, such as concatenating [20211008, 20211010, Hangzhou] into "Hangzhou 20211008" and "Hangzhou 20211010";

[0113] Step 3, assuming that the patient was in Hangzhou on October 9, 2021, the privacy intersection calculation process needs to determine whether a user was in Hangzhou on October 9; at this time, the patient's client is the initiator, and the initiator's itinerary information is "Hangzhou 20211009", and the client of another user is the receiver, and the receiver's arrival itinerary information is "Hangzhou 20211008", and the receiver's departure itinerary information is "Hangzhou 20211010";

[0114] Step 4: The initiator generates a homomorphically encrypted public-private key pair (pk, sk), and then uses the public key to encrypt the initiator's trip information. Specifically, calculate E1 = E pk (Hangzhou 20211009); Then, the initiator sends the encrypted initiator's itinerary information E1 and public key pk to the clients of all other users

[0115] Step 5: Receiver P i Randomly generate two positive numbers r1 and r2 as the first encryption parameter and the second encryption parameter respectively. The receiver uses the public key pk to calculate E pk (r1), E pk (r2), E pk (Hangzhou 20211008), E pk (Hangzhou 20211010), and then the above ciphertext is calculated through homomorphic encryption to obtain the first comparison information E2=E in the encrypted state pk (r1(Hangzhou 20211008-Hangzhou 20211009)), and the second comparison information E3=E in the encrypted state pk (r2(Hangzhou 20211010-Hangzhou 20211009)), and send E2 and E3 back to the initiator;

[0116] Step 6: The initiator uses the private key sk to decrypt and obtain the result of the first comparison information and the second comparison information. Since the time precision is days, it is first determined whether the result is greater than 8 digits. If it is greater than 8 digits, it means that the location information "Hangzhou" does not match, indicating that the receiver P i The corresponding user is not a close contact, otherwise go to step 7;

[0117] Step 7: The initiator checks whether the numerical signs of the results of the first comparison information and the second comparison information are the same. If they are the same, for example, both are positive, it means that the receiver P i The corresponding user does not appear at the specified location at a specific time. If different, the receiver P is determined i The corresponding user is a close contact;

[0118] Step 8: If the receiver P is determined i If the corresponding user is a close contact, the initiator sends a notification message to the receiver, prompting the receiver Pi The corresponding user will isolate himself and report to the community, and send information to the relevant departments to inform them to pay close attention to the recipient P i The corresponding user.

[0119] Through the above steps 1 to 8, in the process of exchanging itinerary information, the initiator calculates the itinerary intersection by comparing the initiator's itinerary information with the receiver's arrival itinerary information and the receiver's departure itinerary information. The initiator performs homomorphic encryption calculations on the itinerary information of each party with the receiver to achieve privacy protection. This solves the problem in related technologies of finding close contacts by publishing the patient's itinerary information, which leads to the leakage of the patient's personal privacy data, protects the patient's privacy, and improves data security.

[0120] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0121] Based on the same inventive concept, the embodiment of the present application also provides a system for obtaining the intersection of private data for implementing the method for obtaining the intersection of private data involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in the embodiments of the system for obtaining the intersection of private data provided below can refer to the limitations of the method for obtaining the intersection of private data above, and will not be repeated here.

[0122] In one embodiment, Figure 7 As shown, a system for obtaining the intersection of private data is provided, including: an initiator 71 and at least one receiver 72, wherein:

[0123] The initiator 71 sends the encrypted initiator's itinerary information to at least one receiver, and the receiver 72 encrypts the itinerary encryption parameter and the receiver's itinerary information respectively;

[0124] Through homomorphic encryption calculation, the receiver 72 determines the size comparison result according to the encrypted initiator's itinerary information and the encrypted receiver's itinerary information, and obtains the itinerary comparison information in an encrypted state according to the size comparison result and the encrypted itinerary information encryption parameter;

[0125] The initiator 71 determines whether there is data intersection between the initiator 71 and the receiver 72 based on the numerical parameters of the decrypted trip comparison information.

[0126] In the process of calculating the privacy intersection of the travel information of the initiator 71 and the receiver 72, the initiator 71 calculates the travel intersection by comparing the initiator's travel information with the receiver's travel information. At the same time, the initiator 71 and the receiver 72 both perform homomorphic encryption calculations on their respective travel information to achieve privacy protection. This solves the problem in related technologies of finding close contacts by publishing the patient's travel information, which leads to the leakage of the patient's personal privacy data, thereby protecting the patient's privacy and improving data security.

[0127] It should be noted that the privacy data intersection acquisition system in the present application can also add a server between the initiator 71 and the receiver 72. The initiator 71 and the receiver 72 record their respective travel information and store it locally to avoid privacy leakage. The server is used to regulate the entire privacy intersection calculation process, for example, notifying the initiator and the receiver to perform privacy intersection calculation on recent travel information.

[0128] In some of the embodiments, when the recipient's itinerary information includes the recipient's arrival itinerary information and the recipient's departure itinerary information, the recipient 72 determines the size comparison result between the encrypted recipient's arrival itinerary information and the encrypted initiator's itinerary information, and obtains first comparison information in an encrypted state based on the size comparison result and the first encryption parameter; the recipient determines the size comparison result between the encrypted recipient's departure itinerary information and the encrypted initiator's itinerary information, and obtains second comparison information in an encrypted state based on the size comparison result and the second encryption parameter.

[0129] In some of the embodiments, the initiator 71 determines whether there is data intersection between the initiator 71 and the receiver 72 according to the number of numerical digits and / or numerical signs of the first comparison information and the second comparison information.

[0130] In some embodiments, the travel information of the initiator and the travel information of the receiver both include time information. When the number of numerical digits of the first comparison information and the second comparison information is greater than the number of numerical digits corresponding to the time information, the initiator 71 determines that there is no data intersection; when the number of numerical digits of the first comparison information and the second comparison information is less than or equal to the number of numerical digits corresponding to the time information, the initiator 71 determines whether there is data intersection between the initiator 71 and the receiver 72 based on the numerical signs of the first comparison information and the second comparison information.

[0131] In some of the embodiments, when the initial trip information of the initiator 71 includes a time period, the initiator 71 converts the initial trip information into a plurality of discrete initiator trip information.

[0132] In some of the embodiments, the initiator 71 expands the initial trip information into multiple discrete initiator trip information according to a preset time accuracy; or, the initiator 71 determines the initiator's starting trip information and the initiator's leaving trip information of the initiator 71 at each location according to the time information and location information in the initial trip information, and uses the initiator's starting trip information and the initiator's leaving trip information as the initiator's trip information, respectively.

[0133] In some of the embodiments, the initiator 71 concatenates the location information in the initial itinerary information of the initiator 71 with the corresponding time information of the initiator in a numerical format to obtain the itinerary information of the initiator; and / or the receiver 72 concatenates the location information in the initial itinerary information of the receiver 72 with the corresponding time information of the receiver in a numerical format to obtain the itinerary information of the receiver.

[0134] In some of the embodiments, if there is data intersection between the initiator 71 and the receiver 72 , the initiator 71 sends notification information to the receiver 72 .

[0135] In some of the embodiments, the initiator 71 records the travel information of the initiator according to its own moving trajectory; and / or the receiver records the travel information of the receiver 72 according to its own moving trajectory.

[0136] Each module in the above-mentioned system for obtaining the intersection of private data can be implemented in whole or in part by software, hardware, or a combination thereof. Each of the above-mentioned modules can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute the operations corresponding to each of the above modules.

[0137] In this embodiment, an electronic device is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor is configured to run the computer program to execute the steps in any one of the above method embodiments.

[0138] Optionally, the electronic device may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor, and the input / output device is connected to the processor.

[0139] Optionally, in this embodiment, the processor may be configured to perform the following steps through a computer program:

[0140] S1, the initiator sends the encrypted initiator's itinerary information to at least one receiver, and the receiver encrypts the itinerary encryption parameters and the receiver's itinerary information respectively.

[0141] S2, through homomorphic encryption calculation, the receiver determines the size comparison result based on the encrypted initiator's itinerary information and the encrypted receiver's itinerary information, and obtains the itinerary comparison information in an encrypted state based on the size comparison result and the encrypted itinerary information encryption parameter.

[0142] S3, the initiator determines whether there is data intersection between the initiator and the receiver based on the numerical parameters of the decrypted itinerary comparison information.

[0143] It should be noted that the specific examples in this embodiment can refer to the examples described in the above embodiments and optional implementation modes, and will not be repeated in this embodiment.

[0144] In addition, in combination with the method for obtaining the intersection of private data provided in the above embodiments, a storage medium may be provided in this embodiment to implement the method. The storage medium stores a computer program; when the computer program is executed by a processor, any method for obtaining the intersection of private data in the above embodiments is implemented.

[0145] It should be understood that the specific embodiments described herein are only used to explain the application, rather than to limit it. Based on the embodiments provided in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of this application.

[0146] Obviously, the drawings are only some examples or embodiments of the present application. For ordinary technicians in the field, the present application can also be applied to other similar situations based on these drawings without creative work. In addition, it is understandable that although the work done in this development process may be complicated and lengthy, for ordinary technicians in the field, certain changes in design, manufacturing or production based on the technical content disclosed in this application are only conventional technical means and should not be regarded as insufficient content disclosed in this application.

[0147] The term "embodiment" in this application refers to a specific feature, structure or characteristic described in conjunction with the embodiment that can be included in at least one embodiment of the present application. The appearance of this phrase in various locations in the specification does not necessarily mean the same embodiment, nor does it mean that it is mutually exclusive with other embodiments and is independent or optional. It is clearly or implicitly understood by those of ordinary skill in the art that the embodiments described in this application can be combined with other embodiments without conflict.

[0148] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of patent protection. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the scope of protection of the present application. Therefore, the scope of protection of the present application shall be subject to the attached claims.

Claims

1. A method for obtaining the intersection of private data, characterized in that: include: Before the initiator sends the encrypted initiator's trip information to at least one recipient, the initiator concatenates the location information in the initiator's initial trip information with the corresponding initiator's time information in a numerical format to obtain the initiator's trip information; The receiver concatenates the location information in the initial itinerary information of the receiver with the corresponding time information of the receiver in numerical format to obtain the itinerary information of the receiver; the receiver encrypts the itinerary encryption parameter and the itinerary information of the receiver respectively; wherein the location information in the concatenated itinerary information is in the front and the time information is in the back; In the case where the receiver's itinerary information includes the receiver's arrival itinerary information and the receiver's departure itinerary information, the receiver determines the size comparison result between the encrypted receiver's arrival itinerary information and the encrypted initiator's itinerary information through homomorphic encryption calculation, and obtains first comparison information in an encrypted state according to the size comparison result and the first encryption parameter; the receiver determines the size comparison result between the encrypted receiver's departure itinerary information and the encrypted initiator's itinerary information, and obtains second comparison information in an encrypted state according to the size comparison result and the second encryption parameter; The initiator determines whether there is data intersection between the initiator and the receiver based on the number of numerical digits and / or numerical signs of the first comparison information and the second comparison information. When the number of numerical digits of the first comparison information and the second comparison information is greater than the number of numerical digits corresponding to the time information, the initiator determines that there is no data intersection; when the number of numerical digits of the first comparison information and the second comparison information is less than or equal to the number of numerical digits corresponding to the time information, the initiator determines whether there is data intersection between the initiator and the receiver based on the numerical signs of the first comparison information and the second comparison information.

2. The method for obtaining the intersection of private data according to claim 1, characterized in that: Before the initiator sends the encrypted initiator travel information to at least one recipient, the method includes: In the case that the initial trip information of the initiator includes a time period, the initiator converts the initial trip information into a plurality of discrete initiator trip information.

3. The method for obtaining the intersection of private data according to claim 2, characterized in that: The initiator converts the initial trip information into a plurality of discrete initiator trip information, including: The initiator expands the initial trip information into a plurality of discrete trip information of the initiator according to a preset time accuracy; or, The initiator determines the initiator's arrival itinerary information and the initiator's departure itinerary information at each location according to the time information and the location information in the initial itinerary information, and uses the initiator's arrival itinerary information and the initiator's departure itinerary information as the initiator's itinerary information.

4. The method for obtaining the intersection of private data according to claim 1, characterized in that: After the initiator determines whether there is data intersection between the initiator and the receiver based on the numerical parameters of the decrypted trip comparison information, the method includes: If the initiator and the receiver have data intersection, the initiator sends notification information to the receiver.

5. The method for obtaining the intersection of private data according to any one of claims 1 to 4, characterized in that: The initiator records the travel information of the initiator according to its own moving track; and / or the receiver records the travel information of the receiver according to its own moving track.

6. A system for obtaining intersection of private data, characterized in that: Includes an initiator and at least one receiver: Before the initiator sends the encrypted initiator's trip information to at least one recipient, the initiator concatenates the location information in the initiator's initial trip information with the corresponding initiator's time information in a numerical format to obtain the initiator's trip information; The receiver concatenates the location information in the initial itinerary information of the receiver with the corresponding time information of the receiver in numerical format to obtain the itinerary information of the receiver; the receiver encrypts the itinerary encryption parameter and the itinerary information of the receiver respectively; wherein the location information in the concatenated itinerary information is in the front and the time information is in the back; In the case where the receiver's itinerary information includes the receiver's arrival itinerary information and the receiver's departure itinerary information, the receiver determines the size comparison result between the encrypted receiver's arrival itinerary information and the encrypted initiator's itinerary information through homomorphic encryption calculation, and obtains first comparison information in an encrypted state according to the size comparison result and the first encryption parameter; the receiver determines the size comparison result between the encrypted receiver's departure itinerary information and the encrypted initiator's itinerary information, and obtains second comparison information in an encrypted state according to the size comparison result and the second encryption parameter; The initiator determines whether there is data intersection between the initiator and the receiver based on the number of numerical digits and / or numerical signs of the first comparison information and the second comparison information. When the number of numerical digits of the first comparison information and the second comparison information is greater than the number of numerical digits corresponding to the time information, the initiator determines that there is no data intersection; when the number of numerical digits of the first comparison information and the second comparison information is less than or equal to the number of numerical digits corresponding to the time information, the initiator determines whether there is data intersection between the initiator and the receiver based on the numerical signs of the first comparison information and the second comparison information.

7. An electronic device comprising a memory and a processor, characterized in that: The memory stores a computer program, and the processor is configured to run the computer program to execute the method for obtaining the intersection of privacy data according to any one of claims 1 to 5.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for obtaining the intersection of privacy data described in any one of claims 1 to 5 are implemented.

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