WO2016048054A2 - Method, apparatus and system for secure data communication - Google Patents

Abstract

The present disclosure relates to technical matters for sensor networks, machine to machine (M2M) communication, machine type communication (MTC) and Internet of Things (IoT). The present disclosure can be used for intelligent services based on these technical matters (smart home, smart building, smart city, smart car, or connected car, healthcare, digital education, retail business, security and safety related services, and the like). A method for transmitting encrypted data from a first device to a second device that prevents identification of the transmitting and receiving devices is disclosed, the method for transmitting data is characterized by comprising the steps of: generating an encryption key for data encryption; generating key identification information using the generated encryption key and encrypting data; and transmitting to the second device a data set including the encrypted data and the key identification information.

Description

Methods, devices, and systems for securing data communications

The present disclosure relates to a method, apparatus, and system for securing data communications.

The Internet has evolved from a human-centered connection network where humans create and consume information, and an Internet of Things (IoT) network that exchanges and processes information among distributed components such as things. The Internet of Everything (IoE) technology, which combines big data processing technology through connection with cloud servers and the like, is emerging. In order to implement the IoT, technical elements such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology are required, and recently, a sensor network for connection between things, a machine to machine , M2M), Machine Type Communication (MTC), etc. are being studied.

In an IoT environment, intelligent Internet technology (IT) services can be provided that collect and analyze data generated from connected objects to create new value in human life. IoT is a field of smart home, smart building, smart city, smart car or connected car, smart grid, health care, smart home appliances, advanced medical services, etc. through convergence and complex of existing information technology (IT) technology and various industries. It can be applied to.

In particular, in the IoT environment, data communication between devices is often performed. In general, a transmitting device and a receiving device transmit and receive encrypted data, and the receiving device needs information about the transmitting device in order to decrypt the encrypted data. Therefore, during data communication, the transmitting device provides the receiving device with information about the transmitting device, such as an IP address. Information can be exposed. However, based on the information of the transmitting device such as the IP address, the third party can obtain a lot of personal information such as the frequency of communication between the transmitting device and the receiving device, the communication device and the receiving device.

Thus, there is an increasing demand for a technology that allows only the receiving device, not the third party, to identify the transmitting device through the encrypted data itself.

In addition, in the IoT environment, the transmitting device and the receiving device generate and exchange encryption keys for encrypted data communication. However, it is common for a transmitting device and a receiving device to generate an encryption key based on the same key data, so that the third device hacks one of the transmitting device and the receiving device, thereby hacking both data transmitted and received between the two devices. Could.

Therefore, the demand for more secure encryption key generation and exchange technology is increasing.

The present invention seeks to provide a secure encryption key generation and exchange technique.

The present invention provides a method for preventing identification of a transmitting / receiving device when exchanging encrypted data, and in particular, a method of preventing identification of a transmitting / receiving device during exchanging encrypted data in a server type message service such as an Internet messenger. In addition, the present invention is to provide a secure key generation and exchange method for encrypted data communication.

According to an embodiment of the present invention, by providing a method and a device for transmitting or receiving encrypted data that prevents identification of the transmitting and receiving device, even if the information of the transmitting and receiving device is not exposed to a third party due to the encrypted data The receiving device can decrypt the encrypted data.

1 illustrates a device for transmitting or receiving encrypted data between a first device and a second device that prevents identification of a transceiving device in accordance with some embodiments.

2 is a flow diagram illustrating a method of transmitting encrypted data that prevents identification of a transceiving device from a first device to a second device in accordance with some embodiments.

3 is a flow diagram illustrating a method of receiving encrypted data from a first device that prevents identification of a transceiving device in a second device in accordance with some embodiments.

4 is a flowchart illustrating a method of transmitting encrypted data using a public key and a random number according to some embodiments.

5 is a flowchart illustrating a method of receiving data encrypted using a public key and a random number according to some embodiments.

6 is a flowchart illustrating a method of transmitting encrypted data using a public key of a receiving device according to some embodiments.

7 is a flowchart illustrating a method of receiving data encrypted using a receiving public key according to some embodiments.

8 is a flowchart of a method for transmitting and receiving encrypted data that prevents identification of a transceiving device using a shared private key in accordance with some embodiments.

9 is a flowchart illustrating a method of transmitting encrypted data that prevents identification of a transmitting / receiving device using an integer that may identify a device, according to some embodiments.

10 is a flowchart illustrating a method of receiving encrypted data that prevents identification of a transceiving device using an integer that may identify the device, in accordance with some embodiments.

FIG. 11 is a flow diagram illustrating a method of receiving encrypted data for obtaining identification of a first device while storing encrypted data in accordance with some embodiments.

12 is a conceptual diagram illustrating a method of transmitting, by a transmitting device, encrypted data for a group of devices according to some embodiments.

FIG. 13 is a flowchart illustrating a matching process for a second device to receive key identification information from a plurality of devices including a first device and to identify a key of a first device that has transmitted data; FIG. do.

14 is a block diagram illustrating a first device that transmits encrypted data to a second device that prevents identification of a transceiving device in accordance with some embodiments.

15 is a block diagram illustrating a device receiving an encrypted data set that prevents identification of a transceiving device in accordance with some embodiments.

16 is a detailed block diagram illustrating a device in accordance with some embodiments.

17 is a conceptual diagram illustrating a system for transmitting and receiving encrypted data that prevents identification of a transceiving device in accordance with some embodiments.

18 is a flow diagram illustrating a method of transmitting encrypted data that prevents identification of a transceiving device in accordance with some embodiments.

19 is a flow diagram illustrating a method of receiving encrypted data that prevents identification of a transceiving device in accordance with some embodiments.

20 and 21 are system diagrams illustrating a key sharing method according to some embodiments.

22 is a flowchart illustrating a key sharing method according to some embodiments.

23 is a flowchart illustrating a key sharing and encryption key generation method in accordance with some embodiments.

24 is a flowchart illustrating a key sharing method according to some embodiments.

25 and 26 illustrate a key sharing method between a first device and a second device for encrypted communication, according to some embodiments.

27 illustrates a SAS generation method according to some embodiments.

28 is a block diagram of a key sharing device in accordance with some embodiments.

29 is a detailed block diagram of a key sharing device in accordance with some embodiments.

Some embodiments for solving the above-described problems of the prior art include a method of transmitting encrypted data in a first device, the method comprising: generating an encryption key for encrypting data to be transmitted; Generating key identification information using the generated encryption key; Encrypting data to be transmitted using the generated encryption key; And transmitting a data set including the encrypted data and the key identification information to a second device.

The key identification information may include identification information of the first device that can be identified by the second device or information that can identify the encryption key.

Generating the encryption key may include transmitting a public key and a first random number of the first device to the second device and receiving a public key and a second random number of the second device from the second device; And generating the encryption key using the public key of the first device and the public key of the second device, wherein the key identification information uses the first random number, the second random number, and the encryption key. The key identification information may include information for identifying the first device based on the first random number or the second random number.

The generating of the key identification information may include: receiving a public key of the second device from the second device; And generating the key identification information by encrypting the encryption key using the received public key of the second device.

Generating the encryption key may include: sharing a private key with a second device; And generating the encryption key using the private key and the first random number, wherein the key identification information includes the first random number and a value obtained by combining the first random number and the encryption key with the first random number. It can contain key-hashed values.

The encryption key is a random number smaller than the identification number Pa of the first device and the identification number Pb of the second device, and the key identification information is the identification number Pa of the first device and the identification number of the second device ( It may be the product of Pb) plus the greatest common divisor plus the random number.

The data set further includes a message authentication code, wherein the message authentication code confirms whether the encryption key obtained by the second device is the same encryption key as the encryption key sent by the first device. Can be used for

Some embodiments for solving the above problems of the prior art include a method of receiving encrypted data at a second device, the method comprising: receiving a data set including encrypted data and key identification information from the first device; Obtaining an encryption key for a first device by using the key identification information; And decrypting the encrypted data by using the obtained encryption key.

The key identification information may include information of a first device that can be identified by a second device or information that can identify the encryption key.

The method further includes receiving at least one public key and at least one random number from at least one device including the first device, respectively, and transmitting the public key and the second random number of the second device to the at least one device, respectively. And obtaining an encryption key for the first device, using at least one public key of the at least one device and the at least one public key of the second device. Generating an encryption key; Generating at least one key identification information using the at least one encryption key; Comparing the generated at least one key identification information with the received key identification information to identify a first device transmitting the encrypted data; And obtaining an encryption key for the identified first device.

The method further includes transmitting a public key of the second device to the first device, and obtaining an encryption key for the first device comprises: key identification information in the received data set; And decrypting the private key corresponding to the public key of the second device to obtain the encryption key.

The method further comprises sharing at least one private key with at least one device including the first device, and receiving the data set from the first one of the at least one device. Receiving encrypted data and key identification information, wherein the key identification information includes a first random number of the first device and a value key-hashed of an encryption key with the first random number. The encryption key is information generated by a combination of a private key shared with the first device and the first random number. The acquiring an encryption key for the first device may include receiving the received first random number. Generating at least one matching key by key-hashing each of the combination values of the at least one private key and the first random number into the first random number; Comparing the generated at least one matching key with a value obtained by key-hashing the encryption key with the received first random number to identify a first device transmitting the data set; And obtaining an encryption key of the first device.

The encryption key may be determined based on at least one of a quotient or the remainder obtained by dividing the key identification information by an identification number of the second device.

The data set further includes a message authentication code, wherein the message authentication code may be used to confirm whether the obtained encryption key is the same encryption key sent by the first device. have.

As a technical means for achieving the above-described technical problem, some embodiments of the present disclosure provide a computer-readable recording medium recording a program for implementing the method.

Some embodiments for solving the problems of the prior art, as a first device for transmitting encrypted data, generating an encryption key, using the generated encryption key to generate key identification information and encrypt the data A control unit; And a transmission / reception unit configured to transmit a data set including the encrypted data and the key identification information to a second device.

The key identification information may include information of the first device that can be identified by the second device or information that can identify the encryption key.

The transceiver transmits the public key and the first random number of the first device to the second device and receives the public key and the second random number of the second device from the second device, the control unit is public of the first device Generate the encryption key using a key and a public key of the second device, the key identification information is generated using the first random number, the second random number and the encryption key, the key identification information is the first It may include information for identifying the first device based on a random number or a second random number.

The transceiver may receive a public key of the second device from a second device, and the key identification information may be generated by encrypting the encryption key using the public key of the second device.

The transmitter / receiver shares the private key with the second device, the controller generates the encryption key using the private key and the first random number, and the key identification information includes the first random number and the first random number. The combined value of encryption keys may be key-hashed with the first random number.

The encryption key includes a random number smaller than an identification number of the first device and an identification number of the second device, and the key identification information is a product or maximum of an identification number of the first device and an identification number of the second device. The common factor may include a value obtained by adding the random number.

Some embodiments for solving the problems of the prior art, the second device for receiving encrypted data, including a transceiver for receiving a data set including the encrypted data and the key identification information from the first device; And a controller configured to obtain an encryption key using the key identification information and to decrypt the received encrypted data using the encryption key, wherein the key identification information is identified by the second device. It may include information of a device or information for identifying the encryption key.

The transceiver receives at least one public key and at least one random number from at least one device including the first device, respectively, and additionally transmits the public key and the second random number of the second device to the at least one device, respectively. The controller may generate at least one encryption key for the at least one device using the received at least one public key and the public key of the second device, and at least one of the at least one encryption key. Generate one key identification information, compare the generated at least one key identification information and the received key identification information to identify the first device, and identify the encryption key for the identified first device Can be obtained.

The transceiver further transmits the public key of the second device to the first device, and the controller decrypts the key identification information using a private key corresponding to the public key of the second device to obtain an encryption key. Can be.

The transceiver further shares at least one private key from at least one device including a first device, receives encrypted data and key identification information from a first device of the at least one device, and the key identification information. Is a key-hashed value of an encryption key with the first random number received from the first device and the first random number, and the encryption key is a private key of the first device and the first random number. And the control unit is configured to key-hash the values obtained by combining the at least one private key and the first random number, respectively, by using the received first random number. A value equal to a value generated by generating at least one matching key and key-hashing the encryption key with the first random number received among the generated at least one matching key Navigate, it may identify the first device, and using the first device and the shared private key and the first random number acquisition of the encryption key.

The encryption key may be determined by a share obtained by dividing the key identification information by an identification number of the second device.

Some embodiments for solving the above-described problems of the prior art, in a method of sharing a key for transmitting encrypted data in the first device, based on the communication history of the first device sent to the second device Determining whether a first public key and a first private key of the first device corresponding to the first public key of the first device are stored; Generating a second public key of the first device and a second private key of the first device based on the determination result; Signing the generated second public key of the first device with the first private key of the first device; And transmitting the signed second public key to a second device.

The method includes receiving a second public key signed with the first private key of the second device from the second device; Obtaining a first public key of the second device corresponding to the first private key of the second device based on the communication details; Verifying the signed second public key with the obtained first public key of the second device; And encrypting communication based on the verification result.

The first public key of the first device and the first private key of the first device may be keys used when performing communication between the first device and the second device.

The first public key of the second device and the first private key of the second device may be keys used when performing communication between the first device and the second device.

The performing of the encrypted communication based on the verification result may generate an encryption key or perform a short authentication string (SAS) calculation based on the verification result.

The method may delete the first private key of the first device, the first public key of the first device, and the first public key of the second device.

The determining may include determining whether the first random number transmitted to the second device when the previous communication is performed is stored, based on the communication details, and wherein the signing is performed based on the communication details. Signing a second random number received from the second device with the first private key of the first device when performing the communication, wherein the transmitting may include transmitting the signed second random number have.

Receiving the signed second public key includes receiving a first random number signed with a first private key of the second device, and wherein the verifying comprises: obtaining a first second device of the obtained second device; And verifying the signed first random number with a first public key.

As a technical means for achieving the above-described technical problem, some embodiments of the present disclosure provide a computer-readable recording medium recording a program for implementing the method.

Some embodiments for solving the above-described problems of the prior art include a first device sharing a key for transmitting encrypted data, wherein the first disclosure of the first device transmitted to the second device based on the communication history; A control unit determining whether a key and a first private key of a first device corresponding to the first public key of the first device are stored; An encryption that generates a second public key of the first device and a second private key of the first device based on the determination result, and signs the generated second public key of the first device with the first private key of the first device part; And a communication unit configured to transmit the signed second public key to a second device.

The communication unit receives a second public key signed with the first private key of the second device from the second device, and the encryption unit corresponds to the first private key of the second device based on the communication details. Acquire a first public key of the second device, verify the signed second public key with the obtained first public key of the second device, and the controller performs encryption communication based on the verification result. Can be determined.

The first public key of the first device and the first private key of the first device may be keys used when performing communication between the first device and the second device.

The first public key of the second device and the first private key of the second device may be keys used when performing communication between the first device and the second device.

The encryption unit may generate an encryption key or perform a SAS (Short Authentication String) calculation based on the verification result.

The encryption unit may delete the first private key of the first device, the first public key of the first device, and the first public key of the second device.

The controller determines whether the first random number transmitted to the second device when the previous communication is performed is stored based on the communication details, and the encryption unit is configured to perform a previous communication on the basis of the communication details. The received second random number is signed with the first private key of the first device, and the communication unit may transmit the signed second random number.

The communication unit may receive a first random number signed with a first private key of the second device, and the encryption unit may verify the signed first random number with the obtained first public key of the second device.

The terms used in the present invention have been selected as widely used general terms as possible in consideration of the functions in the present invention, but this may vary according to the intention or precedent of the person skilled in the art, the emergence of new technologies and the like. In addition, in certain cases, there is also a term arbitrarily selected by the applicant, in which case the meaning will be described in detail in the description of the invention. Therefore, the terms used in the present invention should be defined based on the meanings of the terms and the contents throughout the present invention, rather than the names of the simple terms.

In the present specification, when a part is connected to another part, this includes not only a case in which the part is directly connected, but also a case in which another part is electrically connected in between. In addition, when a part includes a certain component, this means that the component may further include other components, not to exclude other components unless specifically stated otherwise. In addition, the terms "... unit", "module", etc. described in the specification mean a unit for processing at least one function or operation, which may be implemented in hardware or software or a combination of hardware and software. .

In the present specification, the device refers to a personal computer, a cellular phone, a smart phone, a TV, a tablet, a notebook, a personal digital assistant (PDA), a portable multimedia player (PMP), a navigation device, an MP3 player, and a digital device. It may include a device such as a camera, and is not limited to the above examples, may include a variety of devices.

In the present specification, the device key may include a public key (asymmetric key), and may further include a secret key (symmetric key). The device key may mean data used for encrypted communication between devices. The device key may be generated via a key operation algorithm stored in the device. The key operation algorithm may include various algorithms such as AES, MD5, ECDH, and the like, but is not limited to the above examples. In addition, since the key operation algorithm is apparent to those skilled in the art, a detailed description thereof will be omitted.

In the present specification, the key exchange may refer to a procedure in which the first device and the second device transmit and receive at least one of the first device key and the second device key. That is, it may mean a process of transmitting and receiving keys of two devices between two devices.

In the present specification, sharing of a key may mean a process in which a first device transmits and receives a third device key as well as a first device key and a second device key. That is, it may mean a process of transmitting and receiving keys of devices other than the two devices. Of course, key sharing may be a concept involving key exchange. Further, the sharing of the keys may include, but is not limited to, negotiating the key, transmitting the negotiated key, and receiving the negotiated key.

In the present specification, the short range communication method may mean a communication method capable of communicating only when two devices are within a predetermined range, and may include, for example, Bluetooth, NFC, and the like. Of course, it is not limited to the above example.

In the present specification, the telecommunication method may mean a communication method in which two devices can communicate regardless of a distance, and may include a communication method using a cellular network such as an SMS or a phone. Of course, it is not limited to the above example.

In the present specification, a random number may mean an arbitrary value added to a value input to a function in order to vary a value output by a function. For example, if the value inputted to the hash function is the same, the output value is always the same. Therefore, to change the output value, the value of the hash function can be obtained by adding a random number to the input value.

In this specification, the random number of the first device may be referred to as a first random number, and the random number of the second device may be referred to as a second random number. For example, an arbitrary value generated by the first device while transmitting the public key may be referred to as a first random number, and an arbitrary value generated by the second device while transmitting the public key may be referred to as a second random number.

In this specification, a public key is a value that can be distributed to a third party, and can be paired with a private key generated from the public key. In addition, the public key and the private key may be an asymmetric key method. That is, the private key is a value that is not distributed to third parties, and data encrypted with the public key can be decrypted only by the private key.

In this specification, the private key is a value shared between a transmitting and receiving device, that is, a transmitting device and a receiving device, without being exposed to a third party, and may have a meaning of a symmetric key.

In the present specification, a data set may mean a bundle of specific data provided by a data provider and manufactured at a specific time.

In the present specification, a hashing function is a method for calculating a table address for an input value, and may refer to a formula capable of calculating an address at which a record is stored from a given input value. have. The hash function always outputs the same value for the same input. The characteristic of the hash function is that it is easy to obtain the output value using the input value, but it is almost impossible to infer the input value backwards from the output value.

In this specification, a keyed hash may mean a function that additionally requires a key in addition to a basic input value. In the case of a keyless hash function, anyone who knows the given input value can compute the hash value, while in the hash function with the key, only the person with the key can calculate the hash value even if the given input value is known. In the present specification, a hash function having a key of _k may be represented by f _k (x) as f (k, x). Also, f _k (x) may be expressed herein as keyed hashing x to k. Also, a hashed function with keys can be included in the hash function scope.

In the present disclosure, the encryption key may include information for encrypting the data. As an example, the encryption key may include a scrambled key for encrypting an image, but is not limited to the above example. The encryption key may be randomly generated, or may be generated using a public key or a secret key of a device transmitting data or a receiving device. For example, an encryption key may be generated using a key generated by a Diffie-Hellman (D-H) method in a key exchange process of the first device and the second device. Of course, it is not limited to the above example.

In the present specification, the key identification information is information that can be identified only between the transmitting device and the receiving device that transmits the encrypted data, and the receiving device can identify the transmitting device by using the key identification information and decrypt the encrypted data. However, the third party cannot obtain the information of the transmitting device or the receiving device from the key identification information. Therefore, according to an embodiment of the present invention, the privacy of the transmission and reception device may be guaranteed.

In the case of a commercial Internet messenger (IM), the ID used by the IM uses something other than a phone number or a name, and the data is mapped to an IM server to deliver data to a receiving device. Therefore, even if a third party other than the transmitting device and the receiving device captures the packet in the air, it is generally difficult to know the information of the sender / receiver.

However, even in the communication method using IM, not all communication processes are performed in the server. Unencrypted data (for example, message information) in the packet received by the receiving device can be confirmed without performing a separate procedure, but the receiving device must perform decryption to confirm the encrypted data. Therefore, even in a communication method using IM, the transmitting device inserts and provides information of the transmitting device for decryption. Thus, when the third party captures the packet, the encrypted data cannot be decrypted but the possibility of acquiring the information of the transmitting and receiving device cannot be excluded. Tirissa. According to some embodiments, in order to prevent identification of privacy information, the transceiving device may convert or replace information of each device so that it is difficult for a third party to know.

1 illustrates a device for transmitting or receiving encrypted data between a first device and a second device that prevents identification of a transceiving device in accordance with some embodiments.

According to some embodiments, the first device and the second device may be a transmitting device and a receiving device, respectively, and the first device and the second device use the key identification information, thereby allowing the third party to know information about the transmitting device or the receiving device. Make it impossible to identify.

In step 101, a first device transmitting data and a second device receiving data exchange keys with each other. That is, the first device may receive a key of the second device from the second device and transmit the key of the first device. The key of the first device and the key of the second device may comprise a public key or a private key (private key). Also, the first device and the second device may exchange a predetermined value (for example, a random number) generated in each device with a key.

In step 102, according to some embodiments, the first device may generate an encryption key. The encryption key may be generated using a public key or a secret key exchanged with the second device in advance, or may be randomly generated. According to some embodiments, the encryption key may include key data used to encrypt data transmitted between the first device and the second device.

In operation 102, the first device may encrypt data to be transmitted using an encryption key. In addition, the first device may generate key identification information. In some embodiments, the key identification information may be generated before or after encryption of the data.

In operation 103, the first device may transmit key identification information and encrypted data generated in operation 102. According to some embodiments, the first device may transmit the generated key identification information and the encrypted data all at once or separately.

In operation 104, the second device may identify the transmitted first device by using the received key identification information. In addition, the second device derives the encryption key based on the key identification information, but the device other than the first device or the second device (for example, a third party) identifies the transmitting device or the receiving device only with the key identification information. Can not.

According to some embodiments, the key identification information is in a form in which the second device can recognize identification information (eg, ID, name, phone number, device key, etc.) of the first device that the second device can identify. May be encrypted. According to some embodiments, the key identification information may be generated based on at least one of a key of the first device, a key of the second device, a predetermined value generated in each device, and an encryption key exchanged in step 101. .

2 is a flow diagram illustrating a method of transmitting encrypted data that prevents identification of a transceiving device from a first device to a second device in accordance with some embodiments.

In step 201, the first device generates an encryption key. The encryption key may be generated based on a key of the first device sent to the second device or a second device key received from the second device, or may be generated based on a random number.

According to some embodiments, the first device may exchange a device key with the second device. The device key exchanged may include a public key or a private key. The first device and the second device may also generate a random number and exchange the generated random number with a key of each device.

According to some embodiments, the generation of the encryption key may be performed before or after the key exchange of the device between the first device and the second device. The encryption key may be generated based on the key of the exchanged device or the random number exchanged.

In operation 203, the first device may generate key identification information using the generated encryption key and generate encrypted data.

According to some embodiments, the key identification information enables the second device to identify the first device. In other words, since the second device can also generate key identification information based on the device key and the random number exchanged with the first device, the second device can identify the first device. The second device may obtain an encryption key based on the key identification information. Encryption Key According to some embodiments, the first device and the second device may not exchange keys of the device. That is, the first device may generate key identification information based on the identification information of the encryption key first device and the identification information of the second device without exchanging a key of the device.

According to some embodiments, the first device may generate key identification information based on information of an application used by the first device and the second device. For example, the first device may generate key identification information based on information of a predetermined messenger application used with the second device.

The encryption key second device may obtain the encryption key using the key identification information and the identification information of the second device. For example, the identification information of the device may include a phone number, a MAC address, an IP address, a device manufacturing number, etc. of the device, but is not limited to the above example. According to some embodiments, the step of encrypting the data using the encryption key to generate the encrypted data by the first device may be implemented by various known methods. For example, the first device may process the data so that it can be decrypted only by a predetermined key by mixing or randomly rearranging (encrypting) the data according to a predetermined form in order to protect the data.

Further, according to some embodiments, the first device may process the data so that only the person with a specific key can restore the original data by scrambling the data when transmitting the data.

In addition, according to some embodiments, the order of generating key identification information of the first device and generating encrypted data may be changed according to an embodiment.

In operation 205, the first device may transmit a data set including the generated key identification information and the encrypted data to the second device. In addition, when the data transmitted by the first device is image data, the key identification information may be inserted into the image data.

According to some embodiments, the first device may transmit the encryption key by encrypting it with a key of the first device or a key of the second device. For example, the first device may encrypt and provide the encryption key to the second device using the shared key of the first device. The second device may identify the first device based on the key identification information, and decrypt the encryption key encrypted with the shared key of the first device using the shared key of the first device.

According to some embodiments, the first device may transmit a data set to a plurality of devices, including the second device. The first device may encrypt an encryption key with a device key of each of the plurality of devices including the second device, and transmit the encryption key to each of the plurality of devices including the second device together with the key identification information.

According to some embodiments, the first device may encrypt the encryption key using the device key of the second device and provide the encryption key to the second device. The second device may decrypt the encrypted encryption key using the key of the second device.

3 is a flow diagram illustrating a method of receiving encrypted data from a first device that prevents identification of a transceiving device in a second device in accordance with some embodiments.

In operation 301, the second device may exchange a device key with at least one device including the first device. According to some embodiments, the device key may include the device's public key or the device's private key. Further, according to some embodiments, the exchange of device keys may mean at least one of transmitting and receiving respective keys. For example, the first device may transmit a device key of the first device to the second device and receive a device key of the second device from the second device. In addition, if the first device does not need to transmit its own key, receiving the device key of the second device from the second device may be referred to as a key exchange.

According to some embodiments, the second device may exchange a predetermined value, such as a random number, with the first device.

In operation 303, the second device may receive a data set including encrypted data and key identification information from the first device. The second device may determine that the received data set is a data set transmitted and encrypted by the first device based on the key identification information included in the data set. However, since the other device (third party) has not exchanged the device key or the predetermined value with the first device, even if the key identification information included in the data set is acquired, the information about the transmitting device of the data set cannot be obtained. .

According to some embodiments, the data set may further include a message authentication code (MAC). The message authentication code may be used to determine whether the encryption key obtained at the second device receiving the data is the correct encryption key.

In operation 305, the second device may acquire an encryption key using the key identification information. For example, the second device may identify the first device that has transmitted data through the key identification information and obtain an encryption key generated based on an appointment with the first device.

According to some embodiments, the second device may generate an encryption key based on the device key of the first device and the device key of the second device. Further, according to some embodiments, when the encryption key is encrypted with the device key of the second device, the second device may generate with only the device key of the second device itself. In addition, a predetermined value exchanged with each other in a key exchange process may be required for generating an encryption key.

In operation 307, the second device may decrypt the encrypted data using the encryption key. In order to protect the data, the first device mixed or randomly rearranges (encrypts) the data in accordance with a predetermined form to transmit encrypted data which can only be decrypted by a specific key, and the second device acquires in step 305 Data can be decrypted using the encryption key.

4 is a flowchart illustrating a method of transmitting encrypted data using a public key and a random number according to some embodiments.

In step 401, the first device transmits the public key and the first random number of the first device to the second device and receives the public key and the second random number of the second device from the second device. The public keys of the first device and the second device are used to generate an encryption key, and the first random number and the second random number may be used to generate key identification information using the encryption key.

In step 403, the first device generates an encryption key k _ab using the public key of the first device and the public key of the second device. The encryption key according to some embodiments may be generated using public keys of the first device and the second device by means of a Diffie-Hellman (DH) scheme, but is not limited thereto.

In step 405, the first device encrypts the data using the generated encryption key.

In operation 407, the first device generates key identification information k _id using an encryption key k _ab and the first random number and the second random number. The key identification information k _id may be a value obtained by hashing a value obtained by combining the first random number and the second random number with an encryption key. For example, the key identification information is k _id = | nonce_a || nonce_b | k _ab , but is not limited to the above examples.

In step 409, the first device transmits the key identification information and the encrypted data to the second device.

5 is a flowchart illustrating a method of receiving data encrypted using a public key and a random number according to some embodiments.

In step 501, the second device exchanges a public key and a random number with a plurality of external devices including the first device, respectively. In addition, when the only device expected to transmit encrypted data is the first device, the second device may exchange the public key and the random number only with the first device.

In step 503, the second device generates a plurality of encryption keys for the plurality of devices using the received plurality of public keys. For example, the plurality of encryption keys may include an encryption key using a public key of the first device. The encryption key using the public key of the first device may be used when decrypting the encrypted data received from the first device.

In step 505, a plurality of key identification information is generated using the generated plurality of encryption keys, respectively.

In operation 507, the second device compares the generated key identification information with the received key identification information to identify a first device key that has transmitted data.

According to some embodiments, identification of a key selects a public key of the first device from among a plurality of public keys exchanged with a plurality of devices including the first device in step 501 based on the key identification information. Or selecting an encryption key using the public key of the first device.

In step 509, the second device may obtain an encryption key corresponding to the identified first device. In other words, the second device may identify the first device key in step 507 and select or obtain an encryption key corresponding to the first device based on the identification result.

In step 511, the second device decrypts the encrypted data transmitted by the first device using the encryption key for the identified first device.

6 is a flowchart illustrating a method of transmitting, by a first device, an encryption key using a public key of a second device.

In step 601, the first device receives the public key of the second device. Of course, the first device may also transmit the public key of the first device to the second device. In step 602, the first device generates an encryption key for encrypting the data. The encryption key can be randomly generated. In addition, the encryption key may be generated based on at least one public key of the first device and the second device.

In operation 603, the first device encrypts the encryption key g using the public key Pr2 of the second device to generate key identification information k _id . According to some embodiments, the key identification information may be information generated by encrypting an encryption key. For example, the key identification information may be represented by k _id = E_Pr2 (g). Further, according to some embodiments, the key identification information may be a result of a keyed hash with a key, with the input as an encryption key and the hash function key as the public key of the second device. For example, it may be represented by k _id = f _pr2 (g).

In operation 605, the first device transmits the generated key identification information and the data encrypted by the encryption key to the second device.

7 is a flowchart illustrating a method of receiving, by a second device, data encrypted by using a public key of a second device, according to some embodiments.

In step 701, the second device exchanges a key with the first device. For example, the second device may transmit the public key of the second device to the first device.

In operation 703, the second device receives key identification information and encrypted data from the first device.

In operation 705, the second device acquires an encryption key for decrypting data from the received key identification information. The key identification information may be data in which the first device encrypts the encryption key using the public key of the second device. The second device may obtain the encryption key by decrypting the key identification information by using the private key of the second device corresponding to the public key of the second device.

In operation 707, the second device decrypts the received encrypted data using the encryption key obtained in operation 705.

8 is a flowchart of a method for transmitting and receiving encrypted data that prevents identification of a transceiving device using a shared private key in accordance with some embodiments.

In step 801, the first device and the second device share the same private key. The private key is a symmetric key, which is data shared only between the first device and the second device, and may be data that is not exposed to other devices except for the first device and the second device.

According to some embodiments, the sharing of the private key may further include a procedure for transmitting the private keys to each other, as well as a procedure for determining, selecting, or generating the private keys from each other by a predetermined procedure.

In operation 802, the first device generates an encryption key S using the private key and the first random number. According to some embodiments, the private key may include a master key. According to some embodiments, the encryption key may be generated by a predetermined value such as a master key and a nonce, and is not limited to the above example. (Encryption key (S) = Masterkey + predetermined value) (nonceA))

In step 803, the first device transmits a value (session key) obtained by key-hashing the encryption key with the first random number to the second device along with the first random number and the encrypted data. That is, the data transmitted by the first device may include ① first random number, ② session key, and ③ encrypted data.

According to some embodiments, the first device may encrypt data using the generated encryption key.

In step 805, the second device receives the first random number, session key, and encrypted data. The session key may include the message authentication code (MAC) described above.

In operation 807, the second device uses a plurality of candidate encryption keys combining the first random numbers and the private keys MK1 to MKn of all transmission devices including the first device that has been previously shared, using the received first random number. S1 to Sn) are generated.

In operation 809, the second device generates a plurality of candidate matching keys SS1 to SSn by key-hashing each of the generated candidate encryption keys S1 to Sn with a first random number. The plurality of candidate matching keys may be expressed as f _nonceA (S1), f _nonceA (S2), ..., f _nonceA (Sn) as an expression. According to some embodiments, the nonce is a predetermined value and may include a random number generated by the first device or the second device.

In operation 811, the second device may identify the session key of the first device that has transmitted the session key by comparing the generated candidate matching keys SS1 to SSn with the received session key. According to some embodiments, the second device may identify a private key shared with the first device.

In operation 813, the second device may obtain an encryption key based on a combination of the first random number and the private key shared with the first device that has transmitted the data. According to some embodiments, the second device may correspond to the first device. Since the encryption key corresponds to one of the n encryption keys generated in step 809 by the second device, the second device selects one of the candidate encryption keys S1 to Sn generated by the second device based on the session key. It may be. In operation 815, the second device decrypts the data encrypted by the obtained encryption key.

9 is a flowchart illustrating a method of transmitting encrypted data for preventing identification of a transmitting / receiving device using an identification number of a device according to some embodiments.

In step 901, the first device generates an encryption key. According to some embodiments, the encryption key may include a random number smaller than the identification number Pa of the first device and the identification number Pb of the second device.

According to some embodiments, the identification number may include a telephone number or ID, and when the identification number or encryption key is not an integer, the identification number may be converted into an integer by a predetermined table and used in the procedure of FIG. 9. According to some embodiments, the identification number may be an identification key. In step 903, the first device encrypts the data using the encryption key.

In operation 905, the first device uses a cryptographic key to generate a key including a product of the identification number Pa of the first device and the identification number Pb of the second device, or the greatest common divisor, plus a value of the encryption key R. Generate identification information (k _id ). For example, the key identification information may be generated by a formula of k _id = pa * pb + r, but is not limited to the above example.

In operation 907, the first device transmits a data set including the encrypted data and the key identification information to the second device. Operation of the second device receiving the data set will be described in detail with reference to FIG. 10.

10 is a flowchart illustrating a method of receiving encrypted data that prevents identification of a transceiving device using an integer that may identify the device, in accordance with some embodiments.

In operation 1001, the second device receives key identification information Pa * Pb + R and encrypted data.

In step 1003, the second device divides the key identification information Pa * Pb + R by the identification number of the second device and obtains the remaining R. Here, R may be an encryption key for encrypting data by the first device.

In step 1005, the second device decrypts the received encrypted data using the encryption key R.

FIG. 11 is a flow diagram illustrating a method of receiving encrypted data for obtaining identification of a first device while storing encrypted data in accordance with some embodiments.

In operation 1101, the second device acquires identification information of the first device in the process of storing the received encrypted data. The obtaining of the identification information may include, for example, the receiving device selecting a transmitting device among the devices listed in the predetermined list and storing the identification information of the selected transmitting device in addition to the encrypted data.

According to some embodiments, the method for acquiring the identification information of the first device by the second device may be generated by various parameters (eg, random number, private key, etc.) as described above with reference to FIGS. 1 to 10. have.

In addition, according to an embodiment of the present invention, the second device may generate identification information identifying the first device that has transmitted the data while storing the received data.

According to some embodiments, the second device may share a private key with a plurality of devices including the first device.

In operation 1103, the second device acquires a private key of the first device using the acquired identification information of the first device. That is, the second device may obtain the private key of the first device, which is the transmitting device, based on the identification information generated in step 1101.

In step 1105, the second device generates an encryption key using the private key of the first device. According to some embodiments, the private key of the first device may be the same as the encryption key used when the first device encrypts the data.

In step 1107, the second device decrypts the encrypted data using the encryption key.

According to some embodiments, the second device may generate a decryption key corresponding to the encryption key using the encryption key, decrypt the encrypted data using the generated decryption key, and perform decryption using the encryption key. You may.

12 is a conceptual diagram illustrating a method of transmitting, by a transmitting device, encrypted data for a group of devices according to some embodiments.

12A shows a data set generated by a transmitting device when there is only one receiving device. The data set of FIG. 12 (a) may include an encryption key and key identification information generated using a public key.

12B illustrates a data set generated by a transmitting device when the receiving device is a group including a plurality of devices. Unlike the data set of FIG. 12 (b), the data set of FIG. 12 (b) shows a structure of a data set including a plurality of key identification information. Since key identification information is generated for each of the receiving devices, the data set of FIG. 12B may include key identification information corresponding to the number of receiving devices.

FIG. 12 (c) illustrates a structure of a data set including an encrypted public key and encrypted data by encrypting with a public key of a device receiving an encryption key g when there is only one receiving device. The data set of FIG. 12C may include an encryption key encrypted with the public key of the receiving device instead of the key identification information.

12 (d) shows a data set transmitted by a transmitting device when the receiving device is a group including a plurality of devices. Unlike FIG. 12 (c), the data set of FIG. 12 (d) may include a plurality of encryption keys, each of which encrypts an encryption key with a public key of a plurality of devices. For example, E_Pr1 (g) The encryption key g may be encrypted with the public key of the first receiving device, and E_Pr2 (g) may mean that the encryption key g is encrypted with the public key of the second receiving device. c may mean a random number. However, it is not limited to the above example.

According to some embodiments, the data set may include a message authentication code (MAC). The message authentication code may be used to determine whether the encryption key obtained at the receiving device is the correct encryption key. For example, the hash (g || c) of FIG. 12 (d) may be a value for determining which of the plurality of key identification information for the group is key identification information for the device receiving the data set.

For example, when the receiving device receiving the data set decrypts the E_Pr1 (g) value with its own private key, the g value can be obtained. The receiving device may hash the obtained g value and the c value in the data set, and determine whether the hashed value is equal to hash (g || c) in the received data set. The receiving device may determine whether the E_Pr1 (g) value is key identification information for the receiving device according to the determination result. If not the same, the receiving device may repeat the same process for E_Pr2 (g), E_Pr3 (g) and the like to identify key identification information for the receiving device.

FIG. 12E shows the structure of a data set of a method for transmitting encrypted data using an identification number when there is only one receiving device. As described above, the identification number may include data consisting of a predetermined integer such as a telephone number.

According to some embodiments, Pa in FIG. 12 (e) is a phone number of the first device, Pb is a phone number of the second device, and R is a phone number Pa of the first device and a phone of the second device. It may be a random integer smaller than the number Pb. Moreover, even if R is not an integer but a character or a decimal number, it can be converted to an integer by a table or the like and applied to the above-described method.

12 (f) shows the structure of a data set of a method for transmitting data encrypted using an identification number such as a telephone number when the receiving device is a group including a plurality of devices. Unlike in Fig. 12 (e), in the data set of Fig. 12 (f), Pa (telephone number of the transmitting device) * Pb1 (telephone number of the receiver 1) * Pb2 (telephone number of the receiver 2) * Pb3 (of receiver 3) Key identification information generated by the telephone number) + R (encryption key).

According to some embodiments, the receiving device receiving the data set of FIG. 12 (f) of the plurality of devices divides the remaining R (encryption key) by dividing the key identification information by its own phone number regardless of the phone number of another device. Can be obtained.

In addition, the receiving device that receives the data set of FIG. 12 (f) among the plurality of devices may check whether the obtained encryption key is the correct encryption key by using the MAC. For example, the data set may include a random number, key identification information, and a MAC, and the receiving device obtains an encryption key R using the key identification information and key hashes the random value using R as a key. By checking whether it is the same as this MAC, it can confirm whether the obtained encryption key is a correct encryption key.

According to some embodiments, the MAC may be included in other information included in the data set.

FIG. 13 is a flowchart illustrating a matching process for a second device to receive key identification information from a plurality of devices including a first device and to identify a key of a first device that has transmitted data; FIG. do.

According to some embodiments. The matching process may mean a process of searching for the same value by comparing a value received by the second device with a plurality of values stored in the second device (or server).

In step 1301, the second device exchanges keys with a plurality of devices including the first device. According to some embodiments, the key of FIG. 13 may include a public key, a private key, and the like, and is not limited to the above example.

In operation 1303, the second device generates an encryption key using keys exchanged with each of the plurality of devices, and generates a plurality of matching keys for each of the plurality of devices. According to some embodiments, the matching key may also be key identification information for identifying the key. The second device may store at least one of a key, an encryption key, and a matching key exchanged with each of the plurality of devices.

In operation 1305, the second device receives encrypted data and key identification information. According to some embodiments, the second device may receive a data set including encrypted data and key identification information.

In operation 1307, the second device compares the received key identification information with a plurality of matching keys generated in advance. According to some embodiments, the second device may compare the stored matching key with the received key identification information.

In step 1309, the second device identifies the device that sent the encrypted data. In other words, the second device may identify the transmitting device based on the comparison result of step 1307.

In step 1311, the second device derives the encryption key of the device that sent the data.

In operation 1313, the second device may decrypt the encrypted data using the encryption key.

14 is a block diagram illustrating a first device that transmits encrypted data to a second device that prevents identification of a transceiving device in accordance with some embodiments.

According to some embodiments, the first device 1400 includes a controller 1401 and a transceiver 1402.

According to some embodiments, the controller 1401 generates an encryption key, generates key identification information using the generated encryption key, and encrypts the data.

According to some embodiments, the transceiver 1402 transmits a data set including the encrypted data and the key identification information to the second device. Here, the key identification information may include information of the transmitting device that only the receiving device can identify in an encrypted form. The controller 1410 may generate key identification information using not only an encryption key but also at least one of a public key of the second device, an identification number, and a private key of the second device. Since the method for generating the key identification information is as described with reference to FIGS. 1 to 13, a detailed description thereof will be omitted.

15 is a block diagram illustrating a second device for receiving an encrypted data set that prevents identification of a transceiving device, in accordance with an embodiment of the present invention.

According to some embodiments, the second device 1500 includes a controller 1510 and a transceiver 1520.

According to some embodiments, the transceiver 1520 receives a data set including encrypted data and key identification information from the first device. The key identification information may include information of the transmitting device that can be identified by the receiving device in an encrypted form.

According to some embodiments, the controller 1510 may obtain an encryption key using key identification information, and may decrypt data encrypted using the encryption key. For example, the controller 1510 may identify a transmitting device based on key identification information included in the data set received by the transceiver 1520, and may acquire or select an encryption key based on the identification result. The controller 1510 may decrypt the encrypted data using the encryption key. The operation of the controller 1510 to obtain an encryption key corresponds to those described above with reference to FIGS. 1 to 10.

16 is a detailed block diagram illustrating a device in accordance with some embodiments.

According to one embodiment of the invention, the second device is a transceiver for sharing at least one private key with at least one device, including the first device, and receives encrypted data from the first device, the encrypted Identify the first device that transmitted the encrypted data while receiving the data, add or store the identification information of the identified first device to the encrypted data, and share with the first device using the identification information of the first device. A control unit may be configured to identify a private key, generate an encryption key using the private key, and decrypt data encrypted using the encryption key.

Further, according to an embodiment of the present invention, the identification information for identifying the transmission device is generated by a predetermined method by which the reception device can identify the transmission device while receiving data, and by using the identification information of the transmission device. An encryption key for encrypted data can be obtained. The key identification information may be generated based on at least one of a random number exchanged with the second device, a public key, a private key, an identification number, and an application to be used. The method of generating the key identification information by the controller 1670 may include: Since it corresponds to the above description, a detailed description thereof will be omitted.

According to some embodiments, the controller may include at least one of a RAM 1671, a CPU 1673, a ROM 1672, a GPU 1674, and a BUS 1675, and include a RAM 1701 included in the controller, or The ROM 1672 may refer to a storage unit that is the same as or separate from the memory 1620.

According to an embodiment of the present invention, the first device may be a mobile device such as a mobile phone, a smartphone, a PMP, a tablet, an MP3 player, a navigation device or a home device such as a personal computer, a laptop computer, a TV, a monitor, a refrigerator, and the like. It is not limited to.

According to an embodiment of the present invention, the user input unit 1645 receives an input from a user, and may include, for example, a keyboard, a touch pad, a touch screen, a mouse, a trackball, an electronic pen, and the like. It is not limited to the above example. According to some embodiments, the user input unit 1645 may include at least one of a key 1646, a touch panel 1647, and a pen recognition panel 1648.

According to an embodiment of the present invention, the motion detector 1665 may include various sensors such as a GPS, an acceleration sensor, a proximity sensor, a pressure sensor, an illuminance sensor, and the like. In addition, the motion detector 1665 may detect a state of the first device and an event occurring in the first device based on information received from an external device such as a server.

According to an embodiment of the present invention, the transceiver 1630 may include a Wi-Fi chip 1631, a Bluetooth chip 1632, a wireless communication chip 1633, and an NFC chip 1634. The transceiver 1630 may refer to a component that communicates with other devices under the control of the controller 1670.

According to an embodiment of the present invention, the memory 1620 may serve as a main memory device or a secondary memory device embedded in a device such as a RAM, a flash memory, a hard disk, or an SSD. It may include a memory.

Further, according to some embodiments, the first device 1600 may include a GPS chip 1625, an audio processor 1640, a video processor 1630, a microphone 1650, an imaging unit 1655, a speaker 1660, and a display. The display unit 161 may include a panel 1611.

In addition, the first device 1600 may be the same device as the first device 1400 of FIG. 14. In addition, not all components illustrated in FIG. 16 are essential components of the first device 1600. The first device 1600 may be implemented by more components than the components illustrated in FIG. 16, and the first device 1600 may be implemented by fewer components than the components illustrated in FIG. 16. In addition, according to some embodiments, the second device 1500 described above may also include the same configuration as the first device 1600.

The device according to the invention comprises a processor, a memory for storing and executing program data, a permanent storage such as a disk drive, a communication port for communicating with an external device, a user interface such as a touch panel, a key, a button and the like. Devices and the like. Methods implemented by software modules or algorithms may be stored on a computer readable recording medium as computer readable codes or program instructions executable on the processor. The computer-readable recording medium may be a magnetic storage medium (eg, read-only memory (ROM), random-access memory (RAM), floppy disk, hard disk, etc.) and an optical reading medium (eg, CD-ROM). ) And DVD (Digital Versatile Disc). The computer readable recording medium can be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. The medium is readable by the computer, stored in the memory, and can be executed by the processor.

17 is a conceptual diagram illustrating a system for transmitting and receiving encrypted data that prevents identification of a transceiving device in accordance with some embodiments.

A system according to some embodiments may include a first device for transmitting encrypted data and a second device for receiving encrypted data.

The first device may generate an encryption key, encrypt data using the generated encryption key, and transmit a data set including the encrypted data and the key identification information to the second device.

In addition, the second device may receive the data set, obtain an encryption key using the key identification information of the received data set, and decrypt the encrypted data using the obtained encryption key.

According to some embodiments, the first device may transmit the data set to a plurality of device groups (second to nth devices) including the second device. Since this corresponds to the above description, a detailed description thereof will be omitted.

18 is a flowchart illustrating a method of transmitting encrypted data that prevents identification of a transceiving device in accordance with some embodiments.

In step 1810, the first device shares a key with the second device. According to some embodiments, the shared key may include a public key or a private key. In addition, according to some embodiments, the second device may exchange a shared key, a random number, and the like with the first device, which is the same as described above, and thus a detailed description thereof will be omitted.

In operation 1820, the first device generates an encryption key for encrypting data. The encryption key may be generated based on the shared key in step 1810, but may be generated regardless of the shared key. In addition, according to some embodiments, the encryption key may be generated while the first device and the second device exchange keys.

In addition, according to some embodiments, the encryption key may not be generated by the first device. For example, the encryption key generated by the second device may be delivered to the first device in the process of sharing the key.

In operation 1830, the first device encrypts data using the generated encryption key, and encrypts the encryption key using a key shared with the second device. For example, when the key shared with the second device is a public key, the encryption key may be encrypted using the public key of the second device. In this case, the second device may decrypt the encrypted encryption key with its own secret key.

In operation 1840, the first device transmits a data set including the encrypted data, the encrypted encryption key, and the message authentication code to the second device. The message authentication code may be used to confirm whether the encryption key decrypted by the second device is the same as the encryption key transmitted by the first device.

19 is a flow diagram illustrating a method of receiving encrypted data that prevents identification of a transceiving device in accordance with another embodiment of the present invention.

In step 1910, the second device shares a key with the first device. According to some embodiments, the shared key may include a public key or a private key. In addition, according to some embodiments, the second device may exchange a shared key, a random number, and the like with the first device, which is the same as described above, and thus a detailed description thereof will be omitted.

In step 1920, the second device receives a data set from the first device that includes the encrypted data, the at least one encrypted encryption key, and a Message Authentication Code. When there are a plurality of devices receiving encrypted data, a plurality of encrypted encryption keys may be included in the data set received by the second device.

In operation 1930, the second device obtains at least one encryption key using the at least one encrypted encryption key. For example, the second device may be configured to select an encrypted encryption key in the received data set based on the key identification information (for example, a public key, a private key, a shared key, a random number, and an identification number shared in step 1910). At least one).

According to some embodiments, when there are a plurality of devices receiving encrypted data, the second device may obtain a plurality of encryption keys using the plurality of encrypted encryption keys.

In operation 1940, the second device determines a correct encryption key from among the obtained plurality of encryption keys using a message authentication code. For example, the second device may generate a message authentication code using each of the obtained encryption keys and compare the generated message authentication code with the message authentication code included in the received data set. The second device may select an encryption key corresponding to the generated message authentication code that matches the message authentication code included in the received data set.

In operation 1950, the second device decrypts the encrypted data using the encryption key selected in operation 1940.

20 and 21 are system diagrams illustrating a key sharing method according to some embodiments.

Referring to FIG. 20, according to some embodiments, the first device 101 and the second device 102 may perform a first communication. For the first communication, the first device 101 and the second device 102 may generate a public key and a private key, respectively, and share the generated public key. The first device 101 and the second device 102 may generate an encryption key used to encrypt data transmitted and received based on the shared public key and the generated private key.

According to some embodiments, an authentication process may be performed to generate an encryption key during the first communication between the first device 101 and the second device 102. For example, the first device 101 and the second device 102 generate and verify a short authentication string (SAS), thereby mutually (ie, the first device is the second device and the second device is the first device). Device) and generate an encryption key.

According to some embodiments, the first device 101 and the second device 102 may perform a second communication. That is, the first device 101 and the second device 102 may perform a second communication after the first communication. According to some embodiments, the first device 101 and the second device 102 do not generate and verify the SAS when performing the second communication, and identify each other based on the common key information used during the first communication, An encryption key can be generated. If you skip the SAS creation and verification steps, you can exchange keys securely without any hassle.

In the second communication, the first device 101 and the second device 102 may perform encrypted communication based on common key information. More specifically, the first device 101 and the second device 102 can each generate an encryption key based on the common key information. The first device 101 and the second device 102 may compare the generated encryption key to confirm the encryption key and perform encryption communication based on the identified encryption key.

After the encrypted communication, the first device 101 and the second device 102 can delete both the generated public key and the private key, but the information about the generated encryption key can be stored for the next communication. The generated information about the encryption key may be used as common key information in the third communication between the first device 101 and the second device 102.

However, referring to FIG. 21, since the first device 101 and the second device 102 store the same common key information and perform encrypted communication based on the same common key information, the third party 103 is used. If a user hacks either the first device 101 or the second device 102, a third party man-in-the-middle attack (MITM) may be possible. For reference, in the present disclosure, the first communication and the second communication are merely used to distinguish the line after the communication order, and do not mean the first communication.

22 is a flowchart illustrating a key sharing method according to some embodiments.

In operation 2201, the first device may determine whether the first public key of the first device and the first private key of the first device are transmitted to the second device.

According to some embodiments, the first device may receive a communication start request from the second device or the server, and determine whether or not the first device has communicated with the second device before receiving the communication start request based on the communication details. . In addition, when the first device has communicated with the second device before, the first device transmits the first public key of the first device transmitted to the second device and the first device corresponding to the first public key of the first device. 1 It can be determined whether the private key is stored.

According to some embodiments, the first public key of the first device and the first private key of the first device may be a key used in communication (previous communication) that was performed prior to receiving a communication start request. That is, when the previous communication ends, the first device may store the first public key of the first device and the first private key of the first device.

If the first device has never communicated with the first device, the first device may perform a SAS generation and an additional authentication procedure.

In operation 2203, the first device may generate a second public key of the first device and a second private key of the first device based on the determination result.

In step 2205, the first device may sign the generated second public key of the first device with the first private key of the first device.

According to some embodiments, the signature may mean a method of processing data to verify the source through a verification process. For example, if the first device encrypts the data with the public key, the second device decrypts the data encrypted with the private key corresponding to the public key. 2 The device may identify the device that has transmitted the data with the public key corresponding to the private key. Of course, not limited to the above examples, the signature of the present disclosure may include any method of indicating the source.

In step 2207, the first device may transmit the signed second public key to the second device. According to some embodiments, the first device may transmit an unsigned second public key along with a signed second public key. The second device may verify the signed second public key and compare it with the second unsigned public key.

23 is a flowchart illustrating a key sharing and encryption key generation method in accordance with some embodiments.

In step 2301, the first device may receive a second public key signed with the first private key of the second device from the second device. According to some embodiments, the first public key of the second device and the first private key of the second device may be a key used in communication (previous communication) that was performed prior to receiving a communication start request.

In operation 2303, the first device may acquire a first public key of the second device corresponding to the first private key of the second device based on the communication details. According to some embodiments, the first device may obtain a first public key of the second device stored in the first device. That is, the first device may store the first public key of the second device when the previous communication ends.

In operation 2305, the first device may verify a second public key signed with the obtained first public key of the second device. According to some embodiments, the first device may authenticate or identify the second device by verifying the signed second public key.

In operation 2307, the first device may perform encryption communication based on the verification result. According to some embodiments, the first device may generate an encryption key based on the verification result.

For example, when the verification result indicates that the second device is authenticated, the first device may generate an encryption key based on the second private key of the first device and the second public key of the second device.

According to some embodiments, the encryption key may be generated by various methods, for example, by obtaining a predetermined value by calculating a second private key of the first device and a second public key of the second device, By inputting the obtained predetermined value into the key derivation function, data for communication encryption can be obtained. The first device may use some of the communication encryption data as an encryption key, and use the remaining data that is not used as the encryption key among the communication encryption data as the message authentication code (MAC) or key verification data. Of course, it is not limited to the above example, and the encryption key may be generated by various parameters or various methods.

According to some embodiments, when the verification result indicates that the second device is not authenticated, the first device may perform a short authentication string (SAS) calculation. That is, the first device can perform an additional process to authenticate the second device.

For example, the first device performs a hash operation using the second public key of the first device and the second public key of the second device, converts the predetermined word based on the hash operation result, and converts the converted word. May be changed to sound data (eg, voice data) and provided to the first device and the second device.

The first device and the second device output the provided sound data, and the user of the first device and the second device performs authentication between the first device and the second device based on the sound data output from the first device and the second device. May perform certain procedures. Of course, the SAS generated by the first device does not necessarily need to be converted into sound data, and in the case of text data, the first device and the second device may output text data provided through the display unit. In other words, there is no limit to the additional authentication method through SAS.

According to some embodiments, when the current communication is terminated, the first device deletes the first public key of the first device, the first private key of the first device, and the first public key of the second device. The second public key of the first device, the second private key of the first device, and the second public key of the second device may be stored. The stored second public key of the first first device, the second private key of the first device and the second public key of the second device may be used in the next communication.

24 is a flowchart illustrating a key sharing method according to some embodiments.

In operation 2401, the first device may determine whether the first random number transmitted to the second device when the previous communication is performed is stored. According to some embodiments, the first random number may comprise a random number that was used in the communication that was performed between the first device and the second device prior to the current communication start request. In addition, the first random number may include a random number generated by the first device and transmitted to the second device.

In operation 2403, the first device may generate a second public key of the first device and a second private key of the first device based on the determination result. This corresponds to those described with reference to FIGS. 22 to 23.

In operation 2405, the first device may sign the second random number received from the second device when the previous communication is performed with the first private key of the first device. That is, the first device may sign the second random number received from the second device when performing the previous communication with the first private key of the first device used when performing the previous communication.

In step 2407, the first device may transmit a signed second random number to the second device.

In addition, according to some embodiments, the first device may include at least one of a second public key of the first device, a second public key of the first device, and a hash value based on the signed second random number together with the signed second random number. You can send to two devices.

According to some embodiments, the first device may receive a first random number signed with a first private key of the second device. The first device may verify the first random number signed with the first private key of the second device with the first public key of the second device. That is, the first device and the second device may perform the key sharing scheme performed in FIGS. 22 to 23 by using a random number instead of the private key used in the previous step.

According to some embodiments, the first device may perform encrypted communication based on the verification result. Since this corresponds to those described with reference to FIGS. 22 to 23, a detailed description thereof will be omitted.

Further, according to some embodiments, the first device and the second device generate a third random number and a fourth random number for use in the next communication, respectively, before the end of the current communication, and exchange with the first device and the second device. can do. The first device and the second device may perform key sharing when performing the next communication by using the exchanged random number.

According to some embodiments, the first device may sign and store the fourth random number received from the second device with the second private key. In addition, the first device may delete the second private key of the first device after the signature. That is, the first device may not store the private key.

25 and 26 illustrate a key sharing method between a first device and a second device for encrypted communication, according to some embodiments.

Referring to FIG. 25, in operation 2501, a first device may store a first public key of a first device, a first private key of a first device, and a first public key of a second device.

According to some embodiments, the previous communication step of step 2501 may be a step performed in the first communication described with reference to FIG. 20. Also in accordance with some embodiments, the first device stores the first public key of the first device, the first private key of the first device, and the first public key of the second device, and thereafter, a second communication from the second device or server. A communication start request may be received requesting the start of a network.

In operation 2503, the second device may store the public key of the first device, the first private key of the second device, and the first public key of the first device. According to some embodiments, step 2503 may also be a step performed during the first communication described with reference to FIG. 20. According to some embodiments, after the second device has stored the public key of the first device, the first private key of the second device, and the first public key of the first device, the second device initiates a second communication to the first device or server. A communication start request may be sent.

In operation 2505, the first device may generate a second public key of the first device and a second private key of the first device.

In operation 2507, the second device may generate a second public key of the second device and a second private key of the second device.

In step 2509, the first device may sign the second public key of the first device with the first private key of the first device.

In operation 2511, the second device may sign the second public key of the second device with the first private key of the second device. Since steps 2505 to 2511 correspond to those described above with reference to FIGS. 22 to 23, a detailed description thereof will be omitted.

In operation 2513, the first device may transmit the second public key of the first device and the second public key of the first device to the second device.

In step 2515, the second device may transmit the second public key of the second device and the second public key of the second device to the second device.

In operation 2517, the first device may verify a second public key of the second device signed with the first private key of the second device. According to some embodiments, the private key and the public key correspond to each other, data encrypted with the public key can be decrypted with the private key, and data signed with the private key can be verified with the public key.

According to some embodiments, the first device may verify the second public key of the signed second device using the first public key of the second device stored in step 2501. The first device may also compare the second public key of the verified second device to the second public key of the received second device.

In operation 2519, the second device may verify the first public key of the first device signed with the first public key of the first device. According to some embodiments, the second device may verify the second public key of the signed first device using the first public key of the first device stored in step 2503. The second device may also compare the second public key of the verified first device with the second public key of the received first device.

In operation 2521, the first device and the second device may generate and exchange encryption keys based on the verification result. Since encryption key generation and exchange correspond to those described above, a detailed description thereof will be omitted.

Referring to FIG. 26, in operation 2601, the first device may store a first random number transmitted to the second device, a second random number signed with the first public key of the first device, and a first public key of the second device. According to some embodiments, the second random number may comprise a random number received by the first device in a previous communication step from the second device.

The previous communication step of step 2601 may be a step performed in the first communication described with reference to FIG. 20. According to some embodiments, after storing the first random number transmitted to the second device, the second random number signed with the first public key of the first device, and the first public key of the second device, A communication start request may be received from the 2 device or server requesting the start of the second communication.

In operation 2603, the second device may store a first random number signed with the first public key of the second device, a second random number transmitted to the first device, and a first public key of the first device.

The previous communication step of step 2603 may be a step performed in the first communication described with reference to FIG. 20. According to some embodiments, the second device stores a second random number sent to the first device, a first random number signed with the first public key of the second device, and a first public key of the first device, and then stores the second random number. A communication start request may be sent to the first device or server requesting the start of the second communication.

In operation 2605, the first device may generate a second public key of the first device and a second private key of the first device.

In operation 2607, the second device may generate a second public key of the second device and a second private key of the second device.

In step 2609, the first device transmits a hash value generated based on the signed second random number, the second public key of the first device, and the signed second random number, and the second public key of the first device to the second device. can do.

According to some embodiments, the hash value sent by the first device may be used by the second device to verify the first device. Additionally, the first device may be created by further considering the pin number of the first device.

In step 2611, the second device sends to the first device a hash value generated based on the signed first random number, the second public key of the second device, and the signed first random number and the second public key of the second device. can do.

According to some embodiments, the hash value sent by the second device may be used by the first device to verify the second device. Additionally, the second device may be created by further considering the pin number of the second device.

In operation 2613, the first device may verify the first random number signed with the first public key of the second device.

In operation 2615, the second device may verify a second random number signed with the first public key of the first device.

In operation 2617, the first device and the second device may generate and exchange encryption keys based on the verification result. Steps 2613 to 2617 correspond to the above descriptions, and thus a detailed description thereof will be omitted.

27 illustrates a SAS generation method according to some embodiments.

According to some embodiments, the first device may generate the hash value 2705 by inputting the public key 2701 of the first device and the public key 2703 of the second device into a hash function. According to some embodiments, the second device may also generate the hash value in the same manner as the first device.

According to some embodiments, the first device may generate a hash value 2703 and convert the generated hash value into a predetermined word 2707. The first device can transmit the predetermined word 2707 to the second device.

According to some embodiments, the first device outputs a predetermined word 2707 to a user of the first device, and the second device outputs a predetermined word 2707 to the user of the second device, and based on the output predetermined word 2707. By receiving the, the first device and the second device can perform mutual authentication procedure.

28 is a block diagram of a key sharing device in accordance with some embodiments.

As illustrated in FIG. 28, the first device 101, which is a device for inserting watermark data according to some embodiments, may include a controller 2801, a communicator 2803, and a controller 2805. However, not all components illustrated in FIG. 28 are essential components of the first device 101. The first device 101 may be implemented by more components than the components shown in FIG. 28, and the first device 101 may be implemented by fewer components than the components shown in FIG. 28. Further, according to some embodiments, the second device may also include the same configuration as the first device 101.

According to some embodiments, the controller 2801 typically controls the overall operation of the first device 101. For example, the controller 2801 may control overall components included in the first device 101 by executing a program stored in the first device 101. In addition, the controller 2801 may include at least one processor.

According to some embodiments, the controller 2801 may determine whether a public key, a private key, a random number, and the like are stored in the first device based on the communication details. That is, after being used in the previous communication step, the controller 2801 may determine whether the stored public key, private key, random number, etc. are stored for the next communication step and whether there is a previous communication history with the device currently communicating. have.

According to some embodiments, the controller 2801 may include a first individual of the first device corresponding to the first public key of the first device and the first public key of the first device based on the communication history. You can determine if the key is stored. Descriptions of the public key, private key, and random numbers correspond to those described above, and thus detailed descriptions thereof will be omitted.

In addition, according to some embodiments, the controller 2801 may determine whether to perform encrypted communication according to the verification result of the encryption unit 2805. According to some embodiments, the controller 2801 may determine whether to generate an encryption key or perform a SAS calculation.

According to some embodiments, the communication unit 2803 may transmit a public key, a random number, a signed public key, and the like to the second device. The communication unit 2803 may also transmit key verification data or MAC (Message Authentication Code) for the generated encryption key exchange.

According to some embodiments, the communication unit 2803 may transmit the signed second public key to the second device, and may receive a second public key signed with the first private key of the second device from the second device. . Descriptions of the public key, the random number, the signed public key, and the like transmitted and received by the communication unit 2803 correspond to those described above, and thus a detailed description thereof will be omitted.

According to some embodiments, the communication unit 2803 may transmit and receive a communication start request. As described above, sharing and exchanging may include both receiving and transmitting operations.

According to some embodiments, the encryption unit 2805 may sign, verify, encrypt, and decrypt certain data such as a public key. According to some embodiments, the encryption unit 2805 generates a second public key of the first device and a second private key of the first device, and converts the generated second public key of the first device into a first device of the first device. You can sign with your private key. Also, the encryption unit 2805 acquires a first public key of the second device corresponding to the first private key of the second device based on the communication history, and is signed with the obtained first public key of the second device. 2 The public key can be verified. Since the operation of signing, verifying, encrypting, and decrypting the encryption unit 2805 corresponds to those described above, a detailed description thereof will be omitted.

According to some embodiments, when the current communication ends, the encryption unit 2805 may delete data stored after the previous communication. For example, the encryption unit 2805 may delete the first private key of the first device, the first public key of the first device, and the first public key of the second device, which were used in the previous communication. This corresponds to the above description.

According to some embodiments, under the control of the controller 2801 according to the verification result, the encryption unit 2805 may generate an encryption key or perform SAS calculation. Generation of encryption keys and SAS calculations correspond to the operations described above.

28 is a detailed block diagram of a key sharing device in accordance with some embodiments.

As illustrated in FIG. 29, the first device 101, which is a key sharing device according to some embodiments, may include a user input unit 2900 and an output unit 2910 in addition to the control unit 2801, the communication unit 2803, and the encryption unit 2805. ) May further include a sensor unit 2920, an A / V input unit 2950, and a storage unit 2960.

The communication unit 2803 may include one or more components that allow communication between the first device 101 and the second device 102 or an external server. For example, the communicator 2803 may include a short range communicator 2941, a mobile communicator 2943, and a broadcast receiver 2945.

According to some embodiments, the short range communication unit 2939 may include a Bluetooth communication unit, a BLE (Bluetooth Low Energy) communication unit, a near field communication unit (Near Field Communication), a WLAN (WiFi) communication unit, a Zigbee communication unit, an infrared ray (IrDA) Association (Communication) communication unit, WFD (Wi-Fi Direct) communication unit, UWB (ultra wideband) communication unit, Ant + communication unit and the like, but is not limited thereto.

According to some embodiments, the Ant + communication unit is a communication unit that performs wireless communication using a wireless network protocol called ANT having a predetermined standard, such as Bluetooth, and is a low power technology based protocol. The ANT protocol is a protocol that can store various data such as body information as a profile and transmit it to other devices, and will be apparent to those skilled in the art, and thus, detailed description thereof will be omitted. The mobile communication unit 2943 is a base station, an external terminal, Send and receive wireless signals with at least one of the servers. Here, the wireless signal may include various types of data according to transmission and reception of a voice call signal, a video call call signal, or a text / multimedia message.

The broadcast receiving unit 2945 receives a broadcast signal and / or broadcast related information from the outside through a broadcast channel. The broadcast channel may include a satellite channel and a terrestrial channel. According to an implementation example, the first device 101 may not include the broadcast receiver 2945.

The storage unit 2960 may store a program for processing and controlling the control unit 2801, and may store data input to the first device 101 or output from the first device 101. According to some embodiments, the storage unit 2960 may store a public key, a private key, a random number, and the like.

The storage unit 2960 may include a flash memory type, a hard disk type, a multimedia card micro type, and a card type memory (for example, SD or XD memory). RAM, Random Access Memory (RAM), Random Random Access Memory (SRAM), Read-Only Memory (ROM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Programmable Read-Only Memory (PROM), Magnetic At least one type of storage medium may include a memory, a magnetic disk, and an optical disk.

Programs stored in the storage (memory) 2960 may be classified into a plurality of modules according to their functions. For example, the UI module 2961, the touch screen module 2962, the notification module 2963, and the like may be classified into a plurality of modules. Can be classified.

The UI module 2961 may provide a specialized UI, GUI, or the like that is interoperable with the first device 101. For example, the UI module 2961 may provide a UI or GUI for confirming whether the first device 101 is in the process of performing communication with the second device 102.

The touch screen module 2962 may detect a touch gesture on a user's touch screen and transmit information about the touch gesture to the controller 2801. The touch screen module 2962 according to some embodiments may recognize and analyze a touch code. The touch screen module 2962 may be configured as separate hardware including a controller.

Various sensors may be provided inside or near the touch screen to detect a touch or proximity touch of the touch screen. An example of a sensor for sensing a touch of a touch screen is a tactile sensor. The tactile sensor refers to a sensor that senses the contact of a specific object to the extent that a person feels or more. The tactile sensor may sense various information such as the roughness of the contact surface, the rigidity of the contact object, the temperature of the contact point, and the like.

In addition, an example of a sensor for sensing a touch of a touch screen is a proximity sensor.

The proximity sensor refers to a sensor that detects the presence or absence of an object approaching a predetermined detection surface or an object present in the vicinity without using a mechanical contact by using an electromagnetic force or infrared rays. Examples of the proximity sensor include a transmission photoelectric sensor, a direct reflection photoelectric sensor, a mirror reflection photoelectric sensor, a high frequency oscillation proximity sensor, a capacitive proximity sensor, a magnetic proximity sensor, and an infrared proximity sensor. According to some embodiments, the first device 101 may obtain distance information with the second device through the proximity sensor.

The user's touch gesture may include tap, touch and hold, double tap, drag, pan, flick, drag and drop, and swipe.

The notification module 2963 may generate a signal for notifying occurrence of an event of the first device 101. Examples of events occurring in the first device 101 include call signal reception, message reception, key signal input, schedule notification, and the like. The notification module 2963 may output a notification signal in the form of a video signal through the display unit 2911, or may output the notification signal in the form of an audio signal through the sound output unit 2912, or may include a vibration motor 2913. Through the notification signal may be output in the form of a vibration signal. Since the operation performed by the storage unit 2960 corresponds to the above description, a detailed description thereof will be omitted.

The controller 2801 controls the overall operation of the first device 101. Since this corresponds to the above description, a detailed description thereof will be omitted.

The user input receiver 2900 means a means for a user to input data for controlling the first device 101. For example, the user input unit 2900 may include a key pad, a dome switch, a touch pad (contact capacitive type, pressure resistive type, infrared sensing type, surface ultrasonic conduction type, and integral type). Tension measurement method, piezo effect method, etc.), jog wheel, jog switch, etc. may be, but is not limited thereto.

The output unit 2910 may output an audio signal, a video signal, or a vibration signal, and the output unit 2910 may include a display unit 2911, an audio output unit 2912, and a vibration motor 2913. have.

The display unit 2911 displays and outputs information processed by the first device 101.

Meanwhile, when the display unit 2911 and the touch pad form a layer structure to form a touch screen, the display unit 2911 may be used as an input device in addition to the output device. The display unit 2911 includes a liquid crystal display, a thin film transistor-liquid crystal display, an organic light-emitting diode, a flexible display, and a three-dimensional display 3D display, an electrophoretic display. In addition, according to the implementation form of the first device 101, the first device 101 may include two or more display units 2911. In this case, the two or more display units 2911 may be disposed to face each other using a hinge.

The sound output unit 2912 outputs audio data received from the communication unit 2100 or stored in the storage unit (memory) 2940. In addition, the sound output unit 2912 outputs a sound signal related to a function (for example, a call signal reception sound, a message reception sound, and a notification sound) performed by the device 101. The sound output unit 6222 may include a speaker, a buzzer, and the like.

The vibration motor 2913 may output a vibration signal. For example, the vibration motor 6229 may output a vibration signal corresponding to the output of audio data or video data (eg, a call signal reception sound, a message reception sound, and the like). In addition, the vibration motor 2913 may output a vibration signal when a touch is input to the touch screen.

The sensor unit 2920 may detect a state of the first device 101 or a state around the first device 101 and transmit the detected information to the controller 2801.

The sensor unit 2920 may include a geomagnetic sensor 2921, an acceleration sensor 2922, a temperature / humidity sensor 2913, an infrared sensor 2924, a gyroscope sensor 2925, a position sensor (Eg, GPS) 2926, barometric pressure sensor 2927, proximity sensor 2928, and RGB sensor (illuminance sensor) 2929, but are not limited thereto. Since functions of the respective sensors can be intuitively deduced by those skilled in the art from the names, detailed descriptions thereof will be omitted.

The signal acquisition unit (A / V input unit) 2930 is for inputting an audio signal or a video signal, and may include a camera 2951 and a sound input unit 2528. The camera 2951 may obtain an image frame such as a still image or a moving image through an image sensor in a video call mode or a shooting mode. The image captured by the image sensor may be processed by the controller 2801 or a separate image processor (not shown).

The image frame processed by the camera 2951 may be stored in the storage (memory) 2960 or transmitted to the outside via the communication unit 2803. Two or more cameras 2951 may be provided depending on the configuration aspect of the terminal.

The sound input unit 2952 receives an external sound signal and processes the sound signal into electrical voice data. According to some embodiments, the sound input unit 2952 may be a microphone, but is not limited to the above example. The sound input unit 2952 may receive a sound signal from an external device, a server, or a user. In addition, the sound input unit 2952 may use various noise removal algorithms to remove noise generated in the process of receiving an external sound signal.

The device according to the invention comprises a processor, a memory for storing and executing program data, a permanent storage such as a disk drive, a communication port for communicating with an external device, a user interface such as a touch panel, a key, a button and the like. Device and the like. Methods implemented by software modules or algorithms may be stored on a computer readable recording medium as computer readable codes or program instructions executable on the processor. The computer-readable recording medium may be a magnetic storage medium (eg, read-only memory (ROM), random-access memory (RAM), floppy disk, hard disk, etc.) and an optical reading medium (eg, CD-ROM). ) And DVD (Digital Versatile Disc). The computer readable recording medium can be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. The medium is readable by the computer, stored in the memory, and can be executed by the processor.

All documents, including publications, patent applications, patents, and the like, cited in the present invention, may be incorporated into the present invention as if each cited document were individually and specifically shown as merged or as totally merged in the present invention. .

For the understanding of the present invention, reference numerals have been set forth in the preferred embodiments illustrated in the drawings, and specific terms are used to describe the embodiments of the present invention, but the present invention is not limited to the specific terms, and the present invention. May include all components conventionally conceivable to a person skilled in the art.

The invention can be represented by functional block configurations and various processing steps. Such functional blocks may be implemented in various numbers of hardware or / and software configurations that perform particular functions. For example, the present invention relates to integrated circuit configurations such as memory, processing, logic, look-up table, etc., which may execute various functions by the control of one or more microprocessors or other control devices. It can be adopted. Similar to the components in the present invention may be implemented in software programming or software elements, the present invention includes various algorithms implemented in data structures, processes, routines or other combinations of programming constructs, including C, C ++ It may be implemented in a programming or scripting language such as Java, an assembler, or the like. The functional aspects may be implemented with an algorithm running on one or more processors. In addition, the present invention may employ the prior art for electronic environment setting, signal processing, and / or data processing. Terms such as 'mechanism', 'element', 'means' and 'configuration' can be widely used and are not limited to mechanical and physical configurations. The term may include the meaning of a series of routines of software in conjunction with a processor or the like.

Particular implementations described in the present invention are embodiments and do not limit the scope of the present invention in any way. For brevity of description, descriptions of conventional electronic configurations, control systems, software, and other functional aspects of the systems may be omitted. In addition, the connection or connection members of the lines between the components shown in the drawings are illustrative of the functional connection and / or physical or circuit connections as an example, in the actual device replaceable or additional various functional connections, physical It may be represented as a connection, or circuit connections. In addition, if there is no specific reference such as 'essential', 'important' and the like may not be a necessary component for the application of the present invention.

In the specification (particularly in the claims) of the present invention, the use of the term 'above' and similar indicating terms may correspond to both singular and plural. In addition, in the present invention, when the range is described, it includes the invention to which the individual values belonging to the range are applied (if not stated to the contrary), and each individual value constituting the range is described in the detailed description of the invention. Same as Finally, if there is no explicit order or contrary to the steps constituting the method according to the invention, the steps may be performed in a suitable order. The present invention is not necessarily limited to the description order of the above steps. The use of all examples or exemplary terms (eg, etc.) in the present invention is merely for the purpose of describing the present invention in detail, and the scope of the present invention is limited by the examples or exemplary terms unless defined by the claims. It doesn't happen. In addition, one of ordinary skill in the art appreciates that various modifications, combinations and changes can be made depending on design conditions and factors within the scope of the appended claims or equivalents thereof.

Claims (20)

1. A method of transmitting encrypted data at a first device,

   Generating an encryption key for encrypting data to be transmitted;

   Generating key identification information using the generated encryption key;

   Encrypting data to be transmitted using the generated encryption key; And

   Transmitting a data set including the encrypted data and the key identification information to a second device,

   And the key identification information includes identification information of the first device that can be identified by the second device or information that can identify the encryption key.
2. The method of claim 1,

   Generating the encryption key,

   Transmitting the public key and the first random number of the first device to the second device and receiving the public key and the second random number of the second device from the second device; And

   Generating the encryption key using the public key of the first device and the public key of the second device;

   The key identification information is generated using the first random number, the second random number and the encryption key,

   The key identification information may include information for identifying the first device based on the first random number or the second random number.

   How to send encrypted data.
3. The method of claim 1,

   Generating the key identification information,

   Receiving a public key of the second device from the second device; And

   Encrypting the encryption key using the received public key of the second device to generate the key identification information.
4. The method of claim 1,

    Generating the encryption key

   Sharing a private key with a second device; And

   Generating the encryption key using the private key and the first random number;

   And the key identification information comprises a key-hashed value of the first random number and a combination of the first random number and the encryption key into the first random number.
5. As a method of receiving encrypted data at a second device,

   Receiving a data set comprising encrypted data and key identification information from the first device;

   Obtaining an encryption key for a first device by using the key identification information;

   Decrypting the encrypted data using the obtained encryption key;

   And the key identification information includes information of a first device that can be identified by a second device or information that can identify the encryption key.
6. The method of claim 5,

   The method,

   Receiving at least one public key and at least one random number respectively from at least one device including the first device and transmitting the public key and the second random number of the second device to the at least one device, respectively Including,

   Acquiring an encryption key for the first device,

   Generating at least one encryption key for the at least one device using the received at least one public key and the public key of the second device;

   Generating at least one key identification information using the at least one encryption key;

   Comparing the generated at least one key identification information with the received key identification information to identify a first device transmitting the encrypted data; And

   Obtaining an encryption key for the identified first device.
7. The method of claim 5, wherein

   The method,

   Sharing at least one private key with at least one device including the first device,

   Receiving the data set

   Receiving encrypted data and key identification information from the first device of the at least one device,

   The key identification information includes a first random number of the first device and a value of key-hashed an encryption key with the first random number,

   The encryption key is information generated by a combination of a private key and the first random number shared with the first device,

   Acquiring an encryption key for the first device,

   Generating at least one matching key by key-hashing each combination of the at least one private key and the first random number into the first random number using the received first random number;

   Comparing the generated at least one matching key with the received first random number to key-hash the encryption key to identify a first device that has transmitted the data set; And

   Obtaining an encryption key of the first device.
8. A first device for transmitting encrypted data,

   A control unit for generating an encryption key, generating key identification information using the generated encryption key, and encrypting data;

   And a transmission / reception unit configured to transmit a data set including the encrypted data and the key identification information to a second device.

   The key identification information may include information of the first device that can be identified by the second device or information that can identify the encryption key.
9. The method of claim 8,

   The transceiver transmits the public key and the first random number of the first device to the second device and receives the public key and the second random number of the second device from the second device,

   The control unit generates the encryption key using the public key of the first device and the public key of the second device,

   The key identification information is generated using the first random number, the second random number, and the encryption key.

   And the key identification information includes information for identifying the first device based on the first random number or the second random number.
10. The method of claim 8,

    The transceiver receives a public key of the second device from a second device,

    The key identification information is generated by encrypting the encryption key using the public key of the second device.
11. A second device for receiving encrypted data, comprising:

    A transceiver for receiving a data set including encrypted data and key identification information from a first device;

    A control unit for acquiring an encryption key using the key identification information and decrypting the received encrypted data using the encryption key;

    And the key identification information includes information of the first device that can be identified by the second device or information that can identify the encryption key.
12. The method of claim 11,

    The transceiver further transmits the public key of the second device to the first device,

    And the control unit obtains an encryption key by decrypting the key identification information using a private key corresponding to the public key of the second device.
13. A method of sharing a key for transmitting encrypted data at a first device, the method comprising:

    Determining whether the first public key of the first device transmitted to the second device and the first private key of the first device corresponding to the first public key of the first device are stored based on the communication details;

    Generating a second public key of the first device and a second private key of the first device based on the determination result;

    Signing the generated second public key of the first device with the first private key of the first device; And

    Transmitting the signed second public key to a second device.
14. The method of claim 13,

    The method,

    Receiving a second public key signed with the first private key of the second device from the second device;

    Obtaining a first public key of the second device corresponding to the first private key of the second device based on the communication details;

    Verifying the signed second public key with the obtained first public key of the second device; And

    Performing encrypted communication based on the verification result.
15. The method of claim 13,

    And the first public key of the first device and the first private key of the first device are keys used when performing communication between the first device and the second device.
16. The method of claim 13,

    The determining step,

    Determining whether the first random number transmitted to the second device during the previous communication is stored based on the communication details;

    The signing step,

    Signing a second random number received from the second device with a first private key of the first device when performing a previous communication based on the communication history;

    The transmitting step,

    Transmitting the signed second random number.
17. A first device for sharing a key for transmitting encrypted data, the first device comprising:

    A control unit for determining whether a first public key of the first device transmitted to the second device and a first private key of the first device corresponding to the first public key of the first device are stored based on the communication details;

    An encryption that generates a second public key of the first device and a second private key of the first device based on the determination result, and signs the generated second public key of the first device with the first private key of the first device part; And

    And a communication unit for transmitting the signed second public key to a second device.
18. The method of claim 17,

    The communication unit receives a second public key signed with the first private key of the second device from the second device,

    The encryption unit obtains a first public key of the second device corresponding to the first private key of the second device based on the communication history, and signs the first public key of the second device. 2 verify the public key,

    The controller determines whether to perform encrypted communication based on the verification result.
19. The method of claim 17,

    The control unit,

    Determining whether the first random number transmitted to the second device during the previous communication is stored based on the communication details;

    The encryption unit,

    Signing a second random number received from the second device with a first private key of the first device based on the communication history;

    The communication unit,

    Device for transmitting the signed second random number.
20. A computer-readable recording medium having recorded thereon a program for executing the method of any one of claims 1 to 13 on a computer.

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