KR20240058009A - An electronic device for identifying proximity usning homomorphic encypted location information and method for identifying proximity thereof - Google Patents

Abstract

An electronic device is disclosed. The electronic device includes a communication interface, a memory storing at least one instruction, and a processor connected to the communication interface and the memory to control the electronic device, where the processor executes the at least one instruction, thereby homogeneously storing location information of the electronic device. The homomorphic ciphertext generated by encryption is transmitted to the server device using a communication interface, and when the operation result ciphertext obtained based on the operation between the location information of the target device and the homomorphic ciphertext is received from the server device through the communication interface, the operation result ciphertext is decoded to obtain proximity information about the electronic device.

Description

Electronic device for identifying proximity using homomorphically encrypted location information and method for identifying proximity thereof

The present disclosure relates to an electronic device and a method for identifying proximity thereof, and more specifically, to an electronic device and a method for identifying proximity using homomorphically encrypted location information.

Thanks to the development of electronic technology, various services are being provided based on the user's location.

However, in order to provide a service based on the user's location, the user must provide his or her location. In this case, there is a problem that the user's location information may be leaked to a third party.

Accordingly, there is a need to find a way to provide services based on the user's location while protecting the user's location information through encryption technology.

The present disclosure is intended to solve the above-mentioned problems, and the purpose of the present disclosure is to provide an electronic device and a proximity identification method for identifying the distance between the electronic device and the target device using homomorphically encrypted location information.

An electronic device according to an embodiment of the present disclosure includes a communication interface, a memory storing at least one instruction, and a processor connected to the communication interface and the memory to control the electronic device, wherein the processor includes the at least one By executing the instruction, the homomorphic ciphertext generated by homomorphically encrypting the location information of the electronic device is transmitted to the server device using the communication interface, and the operation obtained based on the operation between the location information of the target device and the homomorphic ciphertext When the resulting ciphertext is received from the server device through the communication interface, the operation result ciphertext is decrypted to obtain proximity information about the electronic device.

Additionally, the processor may generate the homomorphic encrypted text by homomorphically encrypting the location information of the electronic device using a public key.

Then, the processor transmits the public key to the server device using the communication interface, and the location information of the target device is determined by the target device using the public key received from the server device. It may contain homomorphic ciphertext generated by homomorphically encrypting information.

Additionally, the location information of the target device may include location information of the target device in plain text.

Additionally, the proximity information about the electronic device may include the distance between the electronic device and the target device.

Additionally, the proximity information for the electronic device may include a first value or a second value. In this case, when the first value is obtained by decrypting the ciphertext as a result of the operation, the processor identifies that the distance between the electronic device and the target device is greater than a preset distance, decrypts the ciphertext as a result of the operation, and obtains the second value by decrypting the ciphertext as a result of the operation. When the value is obtained, it can be identified that the distance between the electronic device and the target device is less than a preset distance.

A method for identifying the proximity of an electronic device according to an embodiment of the present disclosure includes the steps of transmitting a homomorphic ciphertext generated by homomorphically encrypting the location information of the electronic device to a server device, and based on an operation between the location information of the target device and the homomorphic ciphertext. When the obtained ciphertext as a result of the operation is received from the server device, the method includes decoding the ciphertext as a result of the operation to obtain proximity information about the electronic device.

Additionally, the proximity identification method according to one example may further include generating the homomorphic encrypted text by homomorphically encrypting the location information of the electronic device using a public key.

And, the proximity identification method according to an example further includes transmitting the public key to the server device, and the location information of the target device is determined by the target device using the public key received from the server device. It may include a homomorphic ciphertext generated by homomorphically encrypting the location information of the target device.

Additionally, the location information of the target device may include location information of the target device in plain text.

Additionally, the proximity information about the electronic device may include the distance between the electronic device and the target device.

In addition, the proximity information for the electronic device includes a first value or a second value, and the obtaining step is performed when the first value is obtained by decrypting the operation result ciphertext, and the electronic device and the target device If the distance between the devices is identified as being greater than or equal to a preset distance, and the second value is obtained by decrypting the ciphertext as a result of the operation, the distance between the electronic device and the target device may be identified as being less than the preset distance.

According to various embodiments of the present disclosure as described above, the location between the electronic device and the target device can be calculated using homomorphically encrypted location information, thereby ensuring the user's safety and protecting the user's personal information. do..

1 is a diagram for explaining the structure of a network system according to an embodiment of the present disclosure;
2A is a block diagram for explaining the configuration of an electronic device according to an embodiment of the present disclosure;
FIG. 2B is a block diagram for explaining the detailed configuration of an electronic device according to an embodiment of the present disclosure;
3 to 6 are diagrams for explaining a method for an electronic device to obtain accessibility information according to an embodiment of the present disclosure; and
Figure 7 is a flowchart for explaining an accessibility identification method according to an embodiment of the present disclosure.

Hereinafter, the present disclosure will be described in detail with reference to the accompanying drawings. Encryption/decryption may be applied to the information (data) transmission process performed in this disclosure as necessary, and in the present disclosure and patent claims, all expressions describing the information (data) transmission process are encryption/decryption even if not separately mentioned. It should be interpreted to include cases as well. In the present disclosure, expressions such as “transmitted from A to B” or “received by A from B” also include transmission (transmission) or reception with another medium in between, and must be transmitted from A to B. It does not express only what is directly transmitted (delivered) or received.

In the description of the present disclosure, the order of each step should be understood as non-limiting unless the preceding step must be performed logically and temporally prior to the subsequent step. In other words, except for the above exceptional cases, even if the process described as a subsequent step is performed before the process described as a preceding step, the nature of disclosure is not affected, and the scope of rights must also be defined regardless of the order of the steps. In the present disclosure, the term “A or B” is defined to mean not only selectively indicating either A or B, but also including both A and B. In addition, in the present disclosure, the term "includes" has the meaning of including further other components in addition to the elements listed as included.

In this disclosure, only essential elements necessary for description of the present disclosure are described, and components that are unrelated to the essence of the present disclosure are not mentioned. And it should not be interpreted in an exclusive sense that includes only the mentioned components, but in a non-exclusive sense that can include other components as well.

In the present disclosure, a “module” or “unit” performs at least one function or operation, and may be implemented as hardware or software, or as a combination of hardware and software. Additionally, a plurality of “modules” or a plurality of “units” are integrated into at least one module and implemented by at least one processor (not shown), except for “modules” or “units” that need to be implemented with specific hardware. It can be.

In the present disclosure, “value” can be defined as a broad concept that includes not only scalar values but also all values that can be expressed in mathematical expressions such as vectors, matrices, and polynomials.

The mathematical operations and calculations of each step of the present disclosure described later may be implemented as computer operations using known coding methods and/or coding designed to be suitable for the present disclosure to perform the corresponding operations or calculations.

The specific mathematical equations described below are explained as examples among various possible alternatives, and the scope of rights of the present disclosure should not be construed as being limited to the mathematical equations mentioned in the present disclosure.

For convenience of explanation, in this disclosure, the notation is set as follows.

a ← D: Select element (a) according to distribution (D)

s ₁ , s ₂ ∈ R : S1 and S2 are each elements belonging to the set R.

mod(q): Modular operation with q elements

「-」 : Rounds the internal value.

Hereinafter, various embodiments of the present disclosure will be described in detail using the attached drawings.

1 is a diagram for explaining the structure of a network system according to an embodiment of the present disclosure.

Referring to FIG. 1 , the network system may include an electronic device 100, a server device 200, and a target device 300, and these devices may be connected to each other through the network 10.

The electronic device 100 is implemented as various types of devices carried by the user or installed in a fixed location, such as smartphones, tablets, smartwatches, laptops, PCs, home servers, kiosks, home appliances with IoT functions, etc. And location information (e.g. GPS information, etc.) of the electronic device 100 can be collected.

In addition, the target device 300 may be carried by the user, such as a smartphone, tablet, smart watch, smart band, smart necklace, smart tag, electronic anklet, smart tag, location tracker, electronic anklet, etc., or in a vehicle, motorcycle, It is implemented as various types of devices that can be installed on a means of transportation such as a bicycle, and can collect location information (eg, GPS information, etc.) of the target device 300.

FIG. 2A is a block diagram for explaining the configuration of an electronic device according to an embodiment of the present disclosure.

Referring to FIG. 2A , the electronic device 100 may include a communication interface 110, a memory 120, and a processor 130.

The communication interface 110 includes circuitry. The communication interface 110 communicates with an external device (e.g., server device 200, external server, etc.) through the network 10 to transmit various information or data to the external device or receive various information or data from the external device. You can. This communication interface 110 may also be referred to as a transceiver.

For example, the communication interface 110 may include a wired LAN communication module such as an Ethernet module. Additionally, the communication interface 110 may include a wireless communication module such as Wi-Fi (eg, WiFi 802.11a/b/g/n), Bluetooth, ZigBee, NFC, and infrared communication. Additionally, the communication interface 110 may include a cellular communication module such as 3rd Generation (3G), 3rd Generation Partnership Project (3GPP), Long Term Evolution (LTE), and 5G. Additionally, the communication interface 110 may include a wired communication module such as High-Definition Multimedia Interface (HDMI), Universal Serial Bus (USB), etc.

In this way, the communication interface 110 can communicate with an external device using at least one of various types of communication methods.

The memory 120 may store data necessary for the electronic device 100 to operate according to various embodiments of the present disclosure.

For example, the memory 120 may store an operating system operating system (OS) for driving the electronic device 100, various software, data, etc. Additionally, one or more instructions may be stored in the memory 120. This memory 120 may be implemented in various forms such as RAM, ROM, flash memory, HDD, external memory, memory card, etc., and is not limited to any one.

Additionally, a message to be encrypted (e.g., homomorphically encrypted) may be stored in the memory 120. Here, the message may be location information of the electronic device 100.

Additionally, the public key may be stored in the memory 120. When the public key is generated by the electronic device 100, the memory 120 may store not only the public key and the private key, but also various parameters necessary for generating the public key and the private key.

Additionally, the memory 120 may store the homomorphic ciphertext generated in the electronic device 100. Additionally, the memory 120 may store intermediate data (eg, message vector, polynomial message, etc.) in the process of generating homomorphic ciphertext.

Additionally, the memory 120 may store the ciphertext as a result of the operation. The calculation result ciphertext may refer to the result value obtained through the calculation process for the homomorphic ciphertext. This calculation process can be performed by the server device 200, and the server device 200 can transmit the calculation result ciphertext obtained through the calculation process to the electronic device 100.

The processor 130 is connected to each component of the electronic device 100 and can control the overall operation of the electronic device 100. For example, the processor 130 may be connected to the communication interface 110 and the memory 120 to control the electronic device 100. The processor 130 may be composed of a single device such as a central processing unit (CPU) or an application-specific integrated circuit (ASIC), or may be composed of a plurality of devices such as a CPU or a graphics processing unit (GPU).

Additionally, the processor 130 may perform operations of the electronic device 100 according to various embodiments of the present disclosure by executing one or more instructions stored in the memory 120.

FIG. 2B is a block diagram for explaining the configuration of an electronic device according to an embodiment of the present disclosure.

Referring to FIG. 2B, the electronic device 100 includes a communication interface 110, a memory 120, a processor 130, a display 140, a user interface 150, a speaker 160, and a location collection module 170. may include. However, this configuration is an example, and of course, in carrying out the present disclosure, new configurations may be added or some configurations may be omitted in addition to these configurations. Meanwhile, a detailed description of the configuration shown in FIG. 2B that overlaps the configuration shown in FIG. 2A will be omitted.

The display 140 can display various screens. The display 140 may be implemented as a liquid crystal display (LCD), organic light emitting diodes (OLED), etc., and may also be implemented as a touch screen capable of performing the function of the user interface 150, which will be described later.

The processor 130 may display various screens related to various functions provided by the electronic device 100 on the display 140. For example, the display 140 may display text requesting input of parameters necessary for generating a private key and a public key and a user interface window for receiving the corresponding parameters.

User interface 150 may receive user input. User input may include user input for executing various functions provided by the electronic device 100, user input for inputting information necessary for executing various functions, etc. For example, user input may include user input for entering parameters necessary for generating a private key and a public key.

In this case, the user interface 150 may be implemented with buttons, a touch pad, a mouse, and a keyboard. Additionally, the user interface 150 and the display 140 may be implemented as a touch screen to perform a display function and detect a touch operation.

Accordingly, the processor 130 may perform various functions of the electronic device 100 according to user input received through the user interface 150.

The speaker 160 can output not only various types of audio but also various types of notification sounds or voice messages. Accordingly, the processor 130 can output various audio through the speaker 160.

The location collection module 170 may obtain location information of the electronic device 100. Here, the location information may be GPS information, but is not limited to this example.

To this end, the location collection module 160 may include a GPS circuit for receiving GPS signals. Depending on the area or bandwidth of use, GPS can be operated by GLONASS (global navigation satellite system), Beidou Navigation Satellite System, QZSS (quasi-zenith satellite system), IRNSS (indian regional satellite system), or Galileo (the european global satellite-based navigation system). It may include at least one of: The processor 130 may obtain data about the location of the electronic device 100 using the location collection module 170.

Meanwhile, according to an embodiment of the present disclosure, the electronic device 100 may homomorphically encrypt the location information of the electronic device 100 to generate a homomorphic ciphertext and transmit the homomorphic ciphertext to the server device 200. Then, when the electronic device 100 receives the operation result ciphertext, which is the result of the operation on the homomorphic ciphertext, from the server device 200, the electronic device 100 decrypts the operation result ciphertext to identify the distance between the electronic device 100 and the target device 300. You can. In addition, the electronic device 100 provides a notification based on the distance between the electronic device 100 and the target device 300, or provides location information of the electronic device 100 to the server device 200 and/or the police, etc. It can be sent to the management agency that does it.

Hereinafter, it will be described in more detail with reference to the attached drawings.

The processor 130 may generate a homomorphic ciphertext by homomorphically encrypting the location information of the electronic device 100. To this end, the processor 130 may include a module for homomorphically encrypting a message (eg, location information of the electronic device 100).

Specifically, the processor 130 may homomorphically encrypt a message (eg, location information of the electronic device 100) using various parameters and programs stored in the memory 120.

In this case, the processor 130 may include encryption noise, that is, an error calculated in the process of performing homomorphic encryption, in the ciphertext.

Specifically, the homomorphic ciphertext generated by the processor 130 may be generated in a form in which the resulting value including the message and error value is restored when the homomorphic ciphertext is later decrypted using a secret key.

For example, the homomorphic ciphertext generated by the processor 130 may be generated in a form that satisfies Equation 1 below when decrypted using a secret key.

[Equation 1]

Dec(ct, sk) = <ct, sk> = M+e(mod q)

Here, < , > are the inner product, ct is the ciphertext, sk is the secret key, M is the plaintext message, e is the encryption error value, and mod q is the modulus of the ciphertext. q should be selected to be larger than the resulting value M, where the scaling factor (Δ) is multiplied by the message. If the absolute value of the error value e is sufficiently small compared to M, the decryption value M+e of the ciphertext is a value that can replace the original message with the same precision in significant figure calculation. Among the decoded data, the error may be placed on the least significant bit (LSB) side, and M may be placed on the next least significant bit side adjacent to the error.

If the size of the message is too small or too large, the size may be adjusted using a scaling factor. By using a scaling factor, not only messages in the form of integers but also messages in the form of real numbers can be encrypted, thereby greatly increasing usability. Additionally, by adjusting the size of the message using a scaling factor, the size of the area where messages exist in the ciphertext after the operation is performed, that is, the size of the effective area, can also be adjusted.

Depending on the embodiment, the modulus q of the ciphertext may be set and used in various forms. For example, the modulus of the ciphertext may be set in the form q= ^ΔL , the exponent of the scaling factor Δ. If Δ is 2, q=2 can be set to a value such as ¹⁰ .

Meanwhile, a public key may be used for encryption, and the processor 130 may generate the public key necessary to perform encryption. However, it is not limited to this example, and the public key may be received from an external device.

For example, the processor 130 may generate a public key using the Ring-LWE technique. Specifically, the processor 130 may first set various parameters and rings and store them in the memory 120. Examples of parameters may include the length of plaintext message bits and the sizes of public and private keys.

And, the ring can be expressed as Equation 2 below.

[Equation 2]

Here, R is a ring and is a set of nth degree polynomials with Z_q as the coefficient. Zq is a set of coefficients with modulus q of an integer, Zq[x] is a polynomial with coefficients of Zq, and f(x) is a polynomial of degree n.

A ring is a set of polynomials with preset coefficients, in which addition and multiplication are defined between elements, and means a set that is closed with respect to addition and multiplication.

As an example, a ring refers to a set of nth degree polynomials whose coefficients are Zq. If Φ _N (x) is defined as an N-order cyclotomic polynomial, the ring can be expressed as Equation 3 below.

[Equation 3]

Here, R is an N-th cyclotomic polynomial when n is Φ(N). And, Φ(N) is an Euler totient function, which is the number of natural numbers that are coprime to N and smaller than N.

Meanwhile, the secret key (sk) can be expressed as follows.

Meanwhile, the ring in Equation 3 may have a complex number space (i.e., a real domain and an imaginary domain). Meanwhile, during implementation, the operation speed for homomorphic ciphertext can be improved by using only the real space (or real space) of the complex number space of the ring.

Once the ring is set, the processor 130 can calculate the secret key (sk) from the ring.

[Equation 4]

Here, s(x) means a polynomial randomly generated with small coefficients.

And, the processor 130 can calculate the first random polynomial (a(x)) from the ring. The first random polynomial can be expressed as Equation 5 below.

[Equation 5]

Additionally, the processor 130 may calculate an error. Specifically, the processor 130 may extract an error from a discrete Gaussian distribution or a distribution with a statistical distance close to it. This error can be expressed as Equation 6 below.

[Equation 6]

If an error is calculated, the processor 130 may calculate the second random polynomial by modularly calculating the error on the first random polynomial and the secret key. The second random polynomial can be expressed as Equation 7 below.

[Equation 7]

Finally, the processor 130 may generate a public key (pk) in a form including a first random polynomial and a second random polynomial, as shown in Equation 8 below.

[Equation 8]

Since the above-described key generation method is only an example, it is not necessarily limited to this example, and of course, the public key and private key can be generated by other methods.

Depending on the embodiment, the processor 130 may transmit the generated public key to an external device (eg, server device 200) through the communication interface 110. In this case, the processor 130 may transmit the public key to the server device 200 through the communication interface 110 according to a user input or default command.

Additionally, the processor 130 may generate homomorphic ciphertext for the message. Specifically, the processor 130 can generate homomorphic ciphertext by applying a public key to the message. At this time, the processor 130 may generate the length of the ciphertext to correspond to the size of the scaling factor. Meanwhile, when decryption of the homomorphic ciphertext is necessary, the processor 130 can apply a secret key to the homomorphic ciphertext to decrypt the homomorphic ciphertext and generate a message. The message generated at this time may contain an error as mentioned in Equation 1 described above.

Additionally, when the homomorphic ciphertext is generated, the processor 130 may store the homomorphic ciphertext in the memory 120 or transmit it to the server device 200 through the communication interface 110 according to a user request or default command.

Accordingly, as shown in FIG. 3, the processor 130 may generate a public key (S310) and transmit the generated public key to the server device 200 using the communication interface 110 (S315).

Additionally, the processor 130 may generate a homomorphic ciphertext by homomorphically encrypting the location information of the electronic device 100 (S320). In this case, the processor 130 may homomorphically encrypt the location information of the electronic device 100 using a public key to generate a homomorphic ciphertext. Then, the processor 130 may transmit the generated homomorphic ciphertext to the server device 200 using the communication interface 110 (S325).

The server device 200 may transmit the public key received from the electronic device 100 to the target device 300 (S330).

The target device 300 may obtain location information of the target device 300. Here, the location information may be GPS information, but is not limited to this example. To this end, the above target device 300 may include a GPS circuit for receiving GPS signals.

Then, the target device 300 may generate a homomorphic ciphertext by homomorphically encrypting the location information of the target device 300 (S335). That is, when the target device 300 receives the public key from the server device 200, the target device 300 homomorphically encrypts the location information of the target device 300 using the public key received from the server device 200 to generate a homomorphic ciphertext. You can. Then, the target device 300 may transmit the generated homomorphic ciphertext to the server device 200 (S340).

Accordingly, the location information of the target device 300 received by the server device 200 is homomorphically encrypted by the target device 300 using the public key received from the server device 200. It may include a homomorphic ciphertext generated by In this way, the location information of the electronic device 100 collected from the electronic device 100 and the location information of the target device 300 collected from the target device 300 may be encrypted using the same public key.

The server device 200 may calculate the homomorphic ciphertext received from the electronic device 100 and the homomorphic ciphertext received from the target device 300 and obtain an ciphertext as a result of the calculation (S345).

Here, the ciphertext as a result of the operation may mean a ciphertext in which proximity information to the electronic device 100 is homomorphically encrypted.

Proximity information about the electronic device 100 may include the distance between the electronic device 100 and the target device 300. Additionally, depending on the embodiment, the proximity information for the electronic device 100 may include a first value (eg, 1) or a second value (eg, 0). Here, the first value is a value indicating that the distance between the electronic device 100 and the target device 300 is greater than or equal to a preset distance, and the second value is a value indicating that the distance between the electronic device 100 and the target device 300 is greater than or equal to a preset distance. It may be a value indicating that it is less than the distance.

Specifically, due to the nature of homomorphic encryption, operations between homomorphic ciphertexts can be performed without decrypting the homomorphic ciphertext, and operations between homomorphic ciphertext and plaintext can also be performed, and the resulting values of these operations are also in the form of ciphertext.

Accordingly, the server device 200 calculates the location information of the electronic device 100 and the location information of the target device 300 in a homomorphically encrypted state and includes information about the distance between these devices 100 and 300. The calculation result value can be obtained.

Additionally, depending on the embodiment, the server device 200 may compare the result of the operation including information about the distance between the devices 100 and 300 with a preset value using a homomorphic encryption comparison operation. At this time, if the operation result value is more than the preset value, the comparison operation result is calculated as the first value (e.g. 1), and if the operation result value is less than the preset value, the comparison operation result is calculated as the second value (e.g. 0). It can be calculated as: For this purpose, the preset value is set so that when the distance between the electronic device 100 and the target device 300 is greater than or equal to the preset distance, the comparison operation result is calculated as the first value, and also the electronic device 100 and the target device 300 If the distance between 300 is less than a preset distance, the comparison operation result may be set to be calculated as a second value. In this case, the preset distance may be set to a default value, or may be changed and set according to user input.

Then, the server device 200 may transmit the operation result ciphertext to the electronic device 100 (S350).

Meanwhile, when the processor 130 receives the calculation result ciphertext from the server device 200 through the communication interface 110, the processor 130 can decrypt the calculation result ciphertext to identify the distance between the electronic device 100 and the target device 300. There is (S355). Additionally, the processor 130 may provide a notification based on the identified distance (S360).

Specifically, the processor 130 may obtain proximity information about the electronic device 100 by decrypting the ciphertext as a result of the operation. In this case, the processor 130 can decrypt the ciphertext as a result of the operation using the secret key stored in the memory 120.

For example, proximity information obtained through decoding may include the distance between the electronic device 100 and the target device 300. In this case, the processor 130 may identify the distance between the electronic device 100 and the target device 300 using proximity information obtained by decrypting the ciphertext as a result of the operation.

And, when the distance between the electronic device 100 and the target device 300 is less than or equal to the first distance, the processor 130 displays text indicating that the target device 300 has approached the electronic device 100 on the display 140. It can be displayed or a voice message can be output through the speaker 160. Here, the first distance may be 1 km, but is not limited to this example. The first distance may be set to a default value, or may be changed and set according to user input.

In addition, when the distance between the electronic device 100 and the target device 300 is less than or equal to the second distance, the processor 130 sends the location information of the electronic device 100 to the server device 200 and/or the location information through the communication interface 110. Alternatively, it may be transmitted to management authorities, including the police. Here, the second distance may be 100 m, but is not limited to this example. The second distance may be set to a default value, or may be changed and set according to user input. In this case, an organization that manages the server device 200 or a management organization including the police can take measures for the user's safety using the user's location information.

Depending on the embodiment, proximity information obtained through decoding may include a first value or a second value.

In this case, when the first value is obtained by decrypting the ciphertext as a result of the operation, the processor 130 identifies that the distance between the electronic device 100 and the target device 300 is greater than or equal to a preset distance, and decrypts the ciphertext as a result of the operation. When the second value is obtained, it may be identified that the distance between the electronic device 100 and the target device 300 is less than a preset distance. Here, the preset distance may be 1km, but is not limited to this example. The preset distance may be set to a default value, or may be changed and set according to user input.

Additionally, when the processor 130 identifies that the distance between the electronic device 100 and the target device 300 is less than a preset distance, the processor 130 displays text indicating that the target device 300 has approached the electronic device 100 (140). ), or a voice message can be output through the speaker 160.

As such, according to an embodiment of the present disclosure, the electronic device 100 identifies the distance between the electronic device 100 and the target device 300 using the operation result ciphertext received from the server device 200, and identifies the distance between the electronic device 100 and the target device 300. Notifications can be provided depending on the distance covered. Accordingly, the electronic device 100 can provide information on whether a crime victim has approached the user of the electronic device 100, or whether the user of the electronic device 100 has approached a dangerous facility or dangerous area, so that the user's Safety can be ensured.

Additionally, the server device 200 only obtains the calculation result by calculating the homomorphically encrypted location information, and the secret key is not stored in the server device 200. Accordingly, since the server device 200 cannot decrypt the homomorphically encrypted location information received from the electronic device 100, the personal information of the user of the electronic device 100 can also be protected.

Meanwhile, in the above-described example, the electronic device 100 is described as providing a notification when the distance between the electronic device 100 and the target device 300 is short, but this is only an example. That is, when the distance between the electronic device 100 and the target device 300 is greater than or equal to the first distance (or a preset distance), the processor 130 generates text indicating that the target device 300 has moved away from the electronic device 100. can be displayed on the display 140, or a voice message can be output through the speaker 160. In other words, the electronic device 100 provides information on whether a person in need of protection, such as a dementia patient or a child, has left a specific place (e.g., residence, etc.), or whether a car or bicycle owned by the user has left a specific place due to theft, etc. may also be provided.

Meanwhile, in the above-described example, the electronic device 100 transmits the public key to the server device 200, and the target device 300 receives the public key from the server device 200 to provide location information of the target device 300. It was explained that it is homomorphically encrypted and transmitted to the server device 200. However, it is not limited to this example, and the target device 300 may transmit the location information of the target device 300 to the server device 200 without encrypting it.

For example, referring to FIG. 4, the processor 130 may generate a public key (S410) and homomorphically encrypt the location information of the electronic device 100 using the public key to generate a homomorphic ciphertext (S415). ). Then, the processor 130 may transmit the generated homomorphic ciphertext to the server device 200 using the communication interface 110 (S420).

Meanwhile, the target device 300 may acquire location information of the target device 300 and transmit the obtained location information to the server device 200 (S425). That is, the target device 300 can transmit the location information of the target device 300 to the server device 200 without encrypting it. Accordingly, the location information of the target device 300 received by the server device 200 may include the location information of the target device 300 in a plain text state.

The server device 200 may calculate the homomorphic ciphertext received from the electronic device 100 and the location information received from the target device 300 and obtain the ciphertext as a result of the calculation (S430). In this case, as described in FIG. 3, the operation result ciphertext may include proximity information to the electronic device 100.

Then, the server device 200 may transmit the operation result ciphertext to the electronic device 100 (S435). In this case, the processor 130 may decrypt the ciphertext as a result of the operation, identify the distance between the electronic device 100 and the target device 300 (S440), and provide a notification based on the identified distance (S445).

Meanwhile, in the above example, it has been described that there is only one target device 300, but this is not limited to this example, and there may be a plurality of target devices 300 (300-1 to 300-n) (n is 2) or more natural numbers). In this case, the processor 130 may identify the distance between each of the plurality of target devices 300-1 to 300-n and the electronic device 100 and provide a notification accordingly.

For example, as shown in FIG. 5, the processor 130 may generate a public key (S510) and transmit the generated public key to the server device 200 using the communication interface 110 (S515). Additionally, the processor 130 homomorphically encrypts the location information of the electronic device 100 using the public key to generate a homomorphic ciphertext (S520). The generated homomorphic ciphertext can be transmitted to the server device 200 using the communication interface 110 (S525).

The server device 200 may transmit the public key received from the electronic device 100 to a plurality of target devices 300-1 to 300-n (S530-1 to S530-n).

Each of the plurality of target devices 300-1 to 300-n can obtain its own location information. In addition, each of the plurality of target devices 300-1 to 300-n can homomorphically encrypt its location information using the public key received from the server device 200 to generate a homomorphic ciphertext (S535-1 to S535-1). S535-n).

And, each of the plurality of target devices 300-1 to 300-n can transmit the generated homomorphic ciphertext to the server device 200 (S540-1 to S540-n).

The server device 200 may obtain a plurality of operation result ciphertexts by calculating the homomorphic ciphertext received from the electronic device 100 and the homomorphic ciphertext received from each of the plurality of target devices 300-1 to 300-n ( S545).

Then, the server device 200 may transmit the encrypted text resulting from a plurality of calculations to the electronic device 100 (S550).

Meanwhile, when the processor 130 receives a plurality of operation result ciphertexts from the server device 200 through the communication interface 110, the processor 130 decrypts each of the plurality of operation result ciphertexts to provide the electronic device 100 and the plurality of target devices 300 -1 ~ 300-n) The distance between each can be identified (S555). Additionally, the processor 130 may provide a notification based on the identified distance (S560). In this case, notifications may be provided for each target device (300-1 to 300-n).

As another example, as shown in FIG. 6, the processor 130 may generate a public key (S610) and homomorphically encrypt the location information of the electronic device 100 using the public key to generate a homomorphic ciphertext (S615). Then, the processor 130 may transmit the generated homomorphic ciphertext to the server device 200 using the communication interface 110 (S620).

At once, each of the plurality of target devices 300-1 to 300-n can obtain its own location information and transmit the acquired location information to the server device 200 (S625-1 to S625-n). That is, each of the plurality of target devices 300-1 to 300-n can transmit its location information to the server device 200 without encrypting it. Accordingly, the location information of each of the plurality of target devices 300-1 to 300-n received by the server device 200 may include location information in plain text.

The server device 200 may obtain a plurality of operation result ciphertexts by calculating the homomorphic ciphertext received from the electronic device 100 and the location information received from each of the plurality of target devices 300-1 to 300-n ( S630). Then, the server device 200 may transmit the encrypted text resulting from a plurality of calculations to the electronic device 100 (S635).

Meanwhile, when the processor 130 receives a plurality of operation result ciphertexts from the server device 200 through the communication interface 110, the processor 130 decrypts each of the plurality of operation result ciphertexts to provide the electronic device 100 and the plurality of target devices 300 -1 ~ 300-n) The distance between each can be identified (S640). Additionally, the processor 130 may provide a notification based on the identified distance (S645). In this case, notifications may be provided for each target device (300-1 to 300-n).

As such, according to the present disclosure, the processor 130 transmits the operation result ciphertext obtained based on the operation between the location information of the target device 300 and the homomorphic ciphertext of the electronic device 100 to the server device through the communication interface 110. When received from 100, the operation result ciphertext is decrypted to obtain proximity information about the electronic device 100, and a notification can be provided based on the proximity information.

Figure 7 is a flowchart for explaining an accessibility identification method according to an embodiment of the present disclosure.

The homomorphic ciphertext generated by homomorphically encrypting the location information of the electronic device is transmitted to the server device (S710).

Then, when the operation result ciphertext obtained based on the operation between the location information of the target device and the homomorphic ciphertext is received from the server device, the operation result ciphertext is decrypted to obtain proximity information about the electronic device (S720).

Additionally, the location information of the electronic device can be homomorphically encrypted using a public key to generate the homomorphic ciphertext.

Then, the public key can be transmitted to the server device. In this case, the location information of the target device may include a homomorphic encrypted text generated by homomorphically encrypting the location information of the target device using a public key received from the server device.

Additionally, the location information of the target device may include location information of the target device in plain text.

Meanwhile, proximity information about an electronic device may include the distance between the electronic device and the target device.

Additionally, proximity information about the electronic device may include a first value or a second value. In this case, in step S720, if the first value is obtained by decrypting the ciphertext as a result of the operation, the distance between the electronic device and the target device is identified as being greater than or equal to a preset distance, and if the second value is obtained by decrypting the ciphertext as a result of the operation, The distance between the electronic device and the target device may be identified as being less than a preset distance.

Meanwhile, the accessibility identification method according to the various embodiments described above may be implemented in the form of program code for performing each step, and may be stored and distributed on a recording medium. In this case, a device equipped with a recording medium can perform operations such as the above-described encryption or ciphertext processing.

These recording media may be various types of computer-readable media such as ROM, RAM, memory chips, memory cards, external hard drives, hard drives, CDs, DVDs, magnetic disks, or magnetic tapes.

Although the present disclosure has been described above with reference to the accompanying drawings, the scope of rights of the present disclosure is determined by the scope of the patent claims described later and should not be construed as being limited to the above-described embodiments and/or drawings. In addition, it should be clearly understood that improvements, changes and modifications of the disclosure described in the patent claims, which are obvious to those skilled in the art, are also included in the scope of rights of the present disclosure.

100: Electronic device 110: Communication interface
120: Memory 130: Processor
200: server device 300: target device

Claims (12)

In electronic devices,
communication interface;
a memory storing at least one instruction; and
A processor connected to the communication interface and the memory to control the electronic device,
The processor executes the at least one instruction,
Transmitting the homomorphic ciphertext generated by homomorphically encrypting the location information of the electronic device to the server device using the communication interface,
When the operation result ciphertext obtained based on the operation between the location information of the target device and the homomorphic ciphertext is received from the server device through the communication interface, decrypting the operation result ciphertext to obtain proximity information about the electronic device, Electronic devices. According to paragraph 1,
The processor,
An electronic device that homomorphically encrypts location information of the electronic device using a public key to generate the homomorphic ciphertext. According to paragraph 2,
The processor,
Transmitting the public key to the server device using the communication interface,
The location information of the target device is,
An electronic device comprising a homomorphic encrypted text generated by the target device by homomorphically encrypting location information of the target device using the public key received from the server device. According to paragraph 1,
The location information of the target device includes location information of the target device in a plain text state. According to paragraph 1,
The proximity information about the electronic device includes a distance between the electronic device and the target device. According to paragraph 1,
The proximity information for the electronic device includes a first value or a second value,
The processor,
When the first value is obtained by decrypting the ciphertext as a result of the operation, identifying that the distance between the electronic device and the target device is greater than or equal to a preset distance,
When the second value is obtained by decrypting the ciphertext as a result of the operation, the electronic device identifies that the distance between the electronic device and the target device is less than a preset distance. In a method for identifying the proximity of an electronic device,
transmitting a homomorphic encrypted text generated by homomorphically encrypting the location information of the electronic device to a server device; and
When the operation result ciphertext obtained based on the operation between the location information of the target device and the homomorphic ciphertext is received from the server device, decrypting the operation result ciphertext to obtain proximity information about the electronic device; Proximity including; How to identify. In clause 7,
Proximity identification method further comprising: generating the homomorphic encrypted text by homomorphically encrypting the location information of the electronic device using a public key. According to clause 8,
Further comprising: transmitting the public key to the server device,
The location information of the target device is,
A proximity identification method comprising a homomorphic encrypted text generated by the target device by homomorphically encrypting location information of the target device using the public key received from the server device. In clause 7,
The location information of the target device includes location information of the target device in plain text. In clause 7,
Proximity information about the electronic device includes a distance between the electronic device and the target device. In clause 7,
The proximity information for the electronic device includes a first value or a second value,
The obtaining step is,
When the first value is obtained by decrypting the ciphertext as a result of the operation, identifying that the distance between the electronic device and the target device is greater than or equal to a preset distance,
When the second value is obtained by decrypting the ciphertext as a result of the operation, the proximity identification method identifies that the distance between the electronic device and the target device is less than a preset distance.

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