KR101311310B1 - Encryption system and method thereof - Google Patents

Abstract

PURPOSE: An encoding system and a method thereof are provided to strongly protect privacy by using an anonymity ID. CONSTITUTION: A cryptosystem (100) comprises a controller (110) and a communication unit (120). The communication unit obtains encryption information for encoding specific data corresponding to a first user from a server associated with a key distribution center. The controller produces a public key and anonymous ID for the first user based on encryption information which is obtained by controlling the communication unit and produces a coded message based on the public key and specific data. The controller produces a message certification code based of the anonymous ID and transmits the anonymous ID, coded message and message authentication code to a server associated with a management center. [Reference numerals] (110) Controller; (120) Communication unit; (130) Memory unit

Description

Cryptographic system and its method {ENCRYPTION SYSTEM AND METHOD THEREOF}

The present specification relates to a cryptographic system and a method capable of strong privacy protection using an anonymous ID.

When transmitting / saving user A's information to the server, user B can check user A's information stored in the server. When this user A information is sent to the server, data encryption is sent to the server. After that, only a legitimate user B is issued a decryption key to decrypt the encrypted user A's information to verify the contents. have. However, if the user's health information is protected by applying the simple data encryption / decryption process as described above, sufficient privacy protection cannot be obtained.

In addition, when user A's data is stored in the server, the data is stored by applying user A's encryption technology. However, if the server can verify the ID of the encrypted data, the server can sort the cipher texts encrypted with the same ID.

For this reason, the present invention makes it possible to provide anonymity, anonymity, and non-connection to user A on the server side by using user A's anonymous ID.

An object of the present specification is to provide a cryptographic system and a method capable of strong privacy protection using an anonymous ID.

Specifically, in order to protect user A's personal information, in addition to the existing method of encrypting and storing user A's information, only a legitimate user decrypts the encrypted data and uses it again. The purpose of the present invention is to provide a password system and a method that can provide strong privacy protection by proposing a method that provides), unlinkability, and anonymous authentication of the server and user A.

In order to achieve the above objects, a cipher text generation method according to the present specification comprises: obtaining cryptographic information for encrypting specific data corresponding to a first user from a server associated with a key distribution center (KDC); Generating a public key and an anonymous ID for the first user based on the obtained cryptographic information; Generating a cipher text based on the specific data and the public key; Generating a message authentication code based on the anonymous ID; And transmitting the anonymous ID, the cipher text, and the message authentication code to a server associated with a management center (MC).

As an example related to the present specification, the cryptographic information may be at least one of a master public key, a master private key, and a secret value corresponding to the first user.

As an example related to the present specification, the server associated with the management center (MC) generates a target message authentication code, and if the transmitted message authentication code is the same as the target message authentication code, the anonymous ID and It may be to store the cipher text.

As an example related to the present specification, a server associated with a key distribution center (KDC) receives an arrangement for the specific data from a terminal corresponding to a second user, and receives a decryption key corresponding to the arrangement. Generating and transmitting the anonymous ID and the decryption key to a terminal corresponding to the second user.

As an example related to the present specification, a terminal corresponding to the second user transmits the anonymous ID to a server associated with the management center (MC), and a server associated with the management center (MC). , May be to transmit a cipher text corresponding to the anonymous ID to the terminal corresponding to the second user.

As an example related to the present specification, the terminal corresponding to the second user may acquire the specific data by decrypting the cipher text based on the decryption key.

A cryptographic system according to the present disclosure for achieving the above objects comprises: a communication unit for obtaining cryptographic information for encrypting specific data corresponding to a first user from a server associated with a key distribution center (KDC); And generating a public key and an anonymous ID for the first user based on the obtained encryption information, generating a cipher text based on the specific data and the public key, and generating a message authentication code based on the anonymous ID. And a control unit controlling the communication unit to transmit the anonymous ID, the cipher text, and the message authentication code to a server associated with a management center (MC).

A storage medium according to the present disclosure for achieving the above objects, obtains cryptographic information for encrypting specific data corresponding to a first user from a server associated with a key distribution center (KDC), the obtained cryptography Generate a public key and an anonymous ID for the first user based on the information, generate a cipher text based on the specific data and the public key, generate a message authentication code based on the anonymous ID, It may be a storage medium for storing a program for controlling a cryptographic system so that the anonymous ID, the cipher text and the message authentication code is transmitted to a server associated with a management center (MC, Management Center).

According to an embodiment of the present disclosure, there is provided a cryptographic system and method capable of strong privacy protection using an anonymous ID.

In particular, in accordance with the embodiments disclosed herein, the management of user A's sensitive information is not only basic data encryption / decryption process, but also user A's anonymity and disconnection ( Unlinkability and the encryption system capable of anonymous authentication of user A in the authentication process with the data management center and a method thereof can be provided. Therefore, there is an advantage that it is possible not only to hide the contents of information through basic data encryption / decryption using the encryption algorithm, but also to provide a stronger information protection effect by not knowing what user A's information is about the ciphertext.

1 is a block diagram illustrating a cryptographic system according to an embodiment disclosed herein.
2 is a flowchart illustrating a password generation method according to an embodiment disclosed in the present specification.
3 is an exemplary diagram showing a system basic architecture using an anonymous ID.
4 is a message flow diagram in a user registration step.
5 is a message flow diagram in a data transmission step.
6 is a message flow diagram in a data request step.

The technology disclosed herein may be applied to a cryptographic system and method capable of strong privacy protection using anonymous ID. However, the technology disclosed in the present specification is not limited thereto, and may be used in all encryption devices, devices, decryption devices, devices, and methods to which the technical spirit of the technology may be applied.

The technology disclosed herein encrypts and stores the health information of User A in order to protect the privacy of User A (or the first user), and then, if necessary, only a legitimate user decrypts and uses the encrypted data again. In addition, we proposed a mechanism to provide user A's Anonymity and Unlinkability and the server and User A's Anonymous Authentication to obtain a privacy system and its method. to provide.

It is noted that the technical terms used herein are used only to describe specific embodiments and are not intended to limit the scope of the technology disclosed herein. Also, the technical terms used herein should be interpreted as being generally understood by those skilled in the art to which the presently disclosed subject matter belongs, unless the context clearly dictates otherwise in this specification, Should not be construed in a broader sense, or interpreted in an oversimplified sense. In addition, when a technical term used in this specification is an erroneous technical term that does not accurately express the concept of the technology disclosed in this specification, it should be understood that technical terms which can be understood by a person skilled in the art are replaced. Also, the general terms used in the present specification should be interpreted in accordance with the predefined or prior context, and should not be construed as being excessively reduced in meaning.

Also, the singular forms "as used herein include plural referents unless the context clearly dictates otherwise. In this specification, the terms "comprising ", or" comprising "and the like should not be construed as necessarily including the various elements or steps described in the specification, Or may be further comprised of additional components or steps.

Further, the suffix "module" and "part" for the components used in the present specification are given or mixed in consideration of ease of description, and do not have their own meaning or role.

Furthermore, terms including ordinals such as first, second, etc. used in this specification can be used to describe various elements, but the elements should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals are used to designate identical or similar elements, and redundant description thereof will be omitted.

Further, in the description of the technology disclosed in this specification, a detailed description of related arts will be omitted if it is determined that the gist of the technology disclosed in this specification may be obscured. It is to be noted that the attached drawings are only for the purpose of easily understanding the concept of the technology disclosed in the present specification, and should not be construed as limiting the spirit of the technology by the attached drawings.

Terms used in the cryptographic system and method disclosed herein are as follows.

The work disclosed herein Example  Of password systems according to

According to an embodiment of the present disclosure, an encryption system may include: a communication unit obtaining encryption information for encrypting specific data from a specific server, a public key and an anonymous ID for the user based on the obtained encryption information, Generate a cipher text based on the specific data and the public key, generate a message authentication code based on the anonymous ID, and control the communication unit to transmit the anonymous ID, the cipher text and the message authentication code to the specific server. It may include a control unit.

1 is a block diagram illustrating a cryptographic system according to an embodiment disclosed herein.

Referring to FIG. 1, an encryption system 100 according to an exemplary embodiment disclosed herein may include a controller 110 and a communication unit 120.

In addition, the cryptographic system 100 according to the exemplary embodiment disclosed herein may further include a memory unit 130.

In addition, the cryptographic system 100 may further include various components for providing a cryptographic system having a strong privacy protection function using an anonymous ID.

The components shown in FIG. 1 are not essential, such that the cryptographic system 100 with more or less components may be implemented.

Hereinafter, the components will be described in order.

First, the controller 110 may generate an anonymous ID for a public key and a specific user (or first user, user A) based on encryption information obtained from a server associated with a key distribution center (KDC). Can be.

Here, the encryption information may be encryption information for encrypting specific data corresponding to the first user.

For example, the cryptographic information may be at least one of a master public key, a master private key, and a secret value corresponding to the first user.

In addition, the controller 110 may generate a public key and an anonymous ID for the first user based on the obtained encryption information.

In addition, the controller 110 may generate a cipher text based on the specific data and the public key.

Here, the cipher text may be generated based on various algorithms. For example, the cipher text may be generated based on an elliptic curve cryptographic algorithm. In addition, it will be apparent to those skilled in the art that various algorithms may be applied to the cryptographic system and method disclosed herein.

In addition, the controller 110 may generate a message authentication code based on the anonymous ID.

In addition, the controller 110 may control the communication unit to transmit the anonymous ID, the cipher text, and the message authentication code to a server associated with a management center (MC).

The communication unit 120 may communicate with any component inside or any at least one external device, external device, or terminal connected wirelessly or by wire (or through a wired / wireless communication network). . In this case, the external device, the external device or the terminal may include a network service system, a server, and the like.

For example, the communication unit 120 may serve to communicate with a server associated with a key distribution center (KDC) or a server associated with a management center (MC).

According to one embodiment disclosed herein, the communication unit 120 obtains (or receives) cryptographic information for encrypting specific data corresponding to the first user from a server associated with a key distribution center (KDC). can do.

In addition, the communication unit 120 may transmit the anonymous ID, the cipher text, and the message authentication code to a server associated with the management center (MC).

In addition, the communication unit 120 may transmit or receive various information or data necessary for performing the encryption text generation and decryption function based on the anonymous ID.

There may be various wired or wireless communication protocols for the communication.

First, protocols related to near field communication include Bluetooth, Radio Frequency Identification (RFID), infrared data association (IrDA), Ultra Wideband (UWB), ZigBee, Wireless LAN (Bluetooth, 802.11n, etc. protocol), Near Field Communication (NFC) or the like may be used.

In addition, wireless Internet technologies include Wireless LAN (WLAN), Wi-Fi, Wireless Broadband (Wibro), WiMAX (World Interoperability for Microwave Access (Wimax), HSDPA (High Speed Downlink Packet Access). ), IEEE 802.16, Long Term Evolution (LTE), and Wireless Mobile Broadband Service (WMBS) may be used.

In addition, as a protocol or interface related to wired communication, there are a universal serial bus (USB) port, an IEEE1394, a high-definition multimedia interface (HDMI) port, a display port (DP), a wired / wireless headset port, and an external charger. Ports, wired / wireless data ports, memory card ports, ports for connecting devices with identification modules, audio input / output (I / O) ports, video input / output (I / O) ports, earphones Port and the like.

The memory unit 130 may serve to store information processed by the encryption system 100.

The memory unit 130 may store various information such as intermediate calculation values and result values required for the cipher text generation and decryption process.

In addition, the memory unit 130 may store various user interfaces (UIs) and / or graphical user interfaces (GUIs) related to functions performed by the cryptographic system 100.

In addition, the memory unit 130 may store data, a program, and the like necessary for the cryptographic system 100 to operate.

In addition, the memory unit 130 may include a flash memory type, a hard disk type, a multimedia card micro type, a card type memory (eg, SD or XD memory, etc.), magnetic memory, magnetic disk, optical disk, random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM) It may include at least one storage medium of a PROM (Programmable Read-Only Memory), a solid-state drive (SSD). In addition, the image processing apparatus 100 may operate a web storage that performs a storage function of a memory unit on the Internet, or may operate in connection with the web storage.

Looking at the decryption operation after the ciphertext generation in detail, the server associated with the Management Center (MC), may generate a target message authentication code.

The server associated with the management center (MC) may store the anonymous ID and the cipher text when the transmitted message authentication code is the same as the target message authentication code.

The server associated with the key distribution center (KDC) may receive an arrangement for the specific data from a terminal corresponding to the second user.

The server associated with the key distribution center (KDC) may generate a decryption key corresponding to the arrangement, and transmit the anonymous ID and the decryption key to a terminal corresponding to the second user.

The terminal corresponding to the second user may transmit the anonymous ID to a server associated with the management center (MC).

In this case, the server associated with the management center (MC) may transmit a cipher text corresponding to the anonymous ID to the terminal corresponding to the second user.

The terminal corresponding to the second user may acquire the specific data by decrypting the cipher text based on the decryption key.

The work disclosed herein Example  To generate cipher text

In accordance with an embodiment of the present disclosure, a method for generating a cipher text may include obtaining cryptographic information for encrypting specific data corresponding to a first user from a server associated with a key distribution center (KDC), the obtained Generating a public key and an anonymous ID for the first user based on encryption information, generating a cipher text based on the specific data and the public key, and generating a message authentication code based on the anonymous ID And transmitting the anonymous ID, the cipher text, and the message authentication code to a server associated with a management center (MC).

Here, the cryptographic information may be at least one of a master public key, a master private key, and a secret value corresponding to the first user.

2 is a flowchart illustrating a password generation method according to an embodiment disclosed in the present specification.

Referring to FIG. 2, a method for generating and decrypting a cipher according to an exemplary embodiment disclosed herein may be performed by the following steps.

First, the encryption system according to an embodiment disclosed in the present specification may obtain encryption information for encrypting specific data corresponding to the first user from a server associated with a key distribution center (KDC) (S110). ).

Next, the encryption system may generate a public key and an anonymous ID for the first user based on the obtained encryption information (S120).

Next, the cryptographic system may generate an encrypted text based on the specific data and the public key (S130).

Next, the encryption system, based on the anonymous ID can generate a message authentication code (S140).

Next, the cryptographic system may transmit the anonymous ID, the cipher text, and the message authentication code to a server associated with a management center (MC) (S150).

According to one embodiment disclosed herein, the server associated with the management center (MC, Management Center) generates a target message authentication code, if the transmitted message authentication code is the same as the target message authentication code, the anonymous It may be to store the ID and the cipher text.

In addition, according to an embodiment, the server associated with the key distribution center (KDC) receives an arrangement for the specific data from a terminal corresponding to a second user, and receives a decryption key corresponding to the arrangement. Generating and transmitting the anonymous ID and the decryption key to a terminal corresponding to the second user.

In addition, according to an embodiment, the terminal corresponding to the second user, transmits the anonymous ID to the server associated with the management center (MC), the server associated with the management center (MC, Management Center) , May be to transmit a cipher text corresponding to the anonymous ID to the terminal corresponding to the second user.

According to an embodiment of the present disclosure, the terminal corresponding to the second user may acquire the specific data by decrypting the cipher text based on the decryption key.

Specific to the cryptographic system and method disclosed herein Example

Specific embodiments of the cryptographic system and method disclosed herein disclosed herein may be implemented by some or a combination of the components or steps included in the embodiments described above, or may be implemented in a combination of embodiments. Duplicate parts may be omitted for clarity of description of specific embodiments disclosed in the specification.

For the proposed technology, detailed protocols for providing user's Anonymity, Unlinkability and Anonymous authentication are described.

In addition, hereinafter, the expression user A (or first user) or user B (second user) is referred to a terminal (or device, device) or user B (second user) corresponding to user A (or first user). It may be interpreted as a corresponding terminal (or device, device).

The proposed method is divided into three phases: user registration phase, data transmission phase, and data request phase.The dual data transmission phase is divided into public key and anonymous ID generation phase, data encryption and collection phase, data transmission and storage phase Explain in three stages.

3 is an exemplary diagram showing a system basic architecture using an anonymous ID.

Referring to FIG. 3, the KDC may play a role of issuing a key corresponding to a user A (or a first user) and a user B (or a second user) for generating a cipher text and an authentication message, respectively.

In addition, the Management Center (MC) receives the sensing data (or specific data corresponding to the first user) of 'User A' as an encryption key issued from the KDC, generates a cipher text, and transmits the encrypted text to the MC. After storing, the cipher text can be transmitted when a request of 'User B' is requested.

In addition, the user A may periodically transmit its sensing data to the MC by using an encryption key issued from the KDC.

In addition, the user B may request and receive encrypted sensing data of 'User A' from the MC, and may decrypt the decryption key issued from the KDC to check the sensing data of 'User A'.

4 is a message flow diagram in a user registration step.

, 마스터 개인키

그리고 비밀값

을 생성하고 공개키

와 비밀값

를 사용자에게 안전한 채널을 통해 전송한다. 또한 이후 익명 인증을 위해 사용될 키 환

을 생성하여 사용자에게 전송한다.Referring to FIG. 4, referring to a user registration step, a user registers a service with a first key distribution center (KDC). The key distribution center is the master public key for the user

Master private key

And secret

Create a public key

And secret

Is transmitted through a secure channel to the user. It will also be used later for anonymous authentication.

Create and send to the user.

5 is a message flow diagram in a data transmission step.

Referring to FIG. 5, when looking at the data transmission step, the data collection step includes three public key anonymous ID generation steps, data encryption steps, and collection steps. Details are as follows.

end. Generate public key and anonymous ID

)을 생성하고 배열 str을 이용하여 암호화키

와 익명아이디

를 도출한다.User A, who will send the data, will use the array str (e.g.,

) And the encryption key using the array str

And anonymous ID

.

I. Data encryption and collection

와 그에 대응하는 공개키

를 이용하여 타원곡선 암호 알고리즘을 이용하여 암호문

을 생성하고 사용자 A의 암호문을 주기적으로 서버에 전송한다. Of user A to be encrypted and transmitted in the first session

And the corresponding public key

Cipher text using elliptic curve encryption algorithm

And send the password of user A to the server periodically.

)를 생성한다.
In addition, when generating a message authentication code (MAC) for User A's anonymous authentication to MC, the message authentication code (eg, using User A's anonymous ID, not User A's actual ID)

).

All. Data transfer and storage

의 인덱스 j, 암호문

, 익명아이디

그리고 타임스탬프 T를 서버에 전송한다. (

)User A uses the message authentication code and the key used to generate the message authentication code.

Index j, ciphertext

, Anonymous ID

It sends the timestamp T to the server. (

)

을 자신이 만든

와 동일한 값인지 확인하여 같다면 익명아이디와 암호문 쌍

를 저장한다.Server received message authentication code

Made by myself

Check if the value is the same as

Save it.

6 is a message flow diagram in a data request step.

Referring to FIG. 6, referring to the data request step, user B who wants to decrypt the data transmitted by user A to the MC may decrypt the encrypted data before requesting the user A's encrypted data to the server. It may be necessary to obtain a legitimate key and its corresponding anonymous ID from the Key Distribution Center (KDC).

와 복호화 키

를 생성하여 사용자 B에게 전송하여 준다.User B creates the desired array str * and sends it to the key distribution center. The key distribution center is an anonymous ID corresponding to str *.

And decryption key

Create and send to user B.

와 복호화 키

를 전송받은 사용자 B는 익명아이디

를 MC에 전송할 수 있다.Anonymous ID

And decryption key

User B received an anonymous ID

May be transmitted to the MC.

을 상기 사용자 B에 전송할 수 있다.In this case, the MC cipher text corresponding to the MC

Can be transmitted to the user B.

Finally, the user B may obtain the data by decrypting the cipher text based on the decryption key.

As described above, according to the cryptographic system and method disclosed herein, in the defense aspect, information related to high-level personnel should be classified and treated as sensitive information in military personnel management. By proposing techniques to provide strong privacy protection for high-level personnel. Therefore, it can be applied to military systems that want to minimize information exposure of high-level personnel.

On the private side, user A's management of sensitive information includes not only basic data encryption / decryption but also user A's anonymity and unlinkability and authentication with the data management center. Can provide user A's anonymous authentication.

Therefore, it is possible to achieve stronger information protection by not only hiding the contents of information through basic data encryption / decryption using encryption algorithm but also not knowing what user A's information is about the ciphertext.

In addition, in order to protect User A's personal information, in addition to the existing method of encrypting and storing User A's health information, only a legitimate user decrypts and uses the encrypted data again. In addition, we propose a scheme that provides anonymous and unlinkability and anonymous authentication of the server and user A.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

100: password system 110: control unit
120: communication unit 130: memory unit

Claims (8)

Obtaining cryptographic information for encrypting specific data corresponding to the first user from a server associated with a key distribution center (KDC);
Generating a public key and an anonymous ID for the first user based on the obtained cryptographic information;
Generating a cipher text based on the specific data and the public key;
Generating a message authentication code based on the anonymous ID; And
And transmitting the anonymous ID, the cipher text, and the message authentication code to a server associated with a management center (MC). The method of claim 1, wherein the encryption information,
And at least one of a master public key, a master private key, and a secret value corresponding to the first user. The method of claim 1, wherein the server associated with the management center (MC),
Generate the target message verification code,
And if the transmitted message authentication code is the same as the target message authentication code, storing the anonymous ID and the cipher text. The server of claim 2, wherein the server associated with the key distribution center (KDC) comprises:
Receiving an arrangement for the specific data from a terminal corresponding to a second user,
Generate a decryption key corresponding to the array;
And transmitting the anonymous ID and the decryption key to a terminal corresponding to the second user. The terminal of claim 4, wherein the terminal corresponding to the second user comprises:
The anonymous ID is transmitted to the server associated with the management center (MC),
The server associated with the management center (MC) is to transmit a cipher text corresponding to the anonymous ID to the terminal corresponding to the second user. The terminal of claim 4, wherein the terminal corresponding to the second user comprises:
And decrypting the cipher text based on the decryption key to obtain the specific data. A communication unit for obtaining cryptographic information for encrypting specific data corresponding to the first user from a server associated with a key distribution center (KDC); And
Generate a public key and an anonymous ID for the first user based on the obtained cryptographic information,
Generate a cipher text based on the specific data and the public key,
Generate a message authentication code based on the anonymous ID,
And a control unit for controlling the communication unit to transmit the anonymous ID, the cipher text, and the message authentication code to a server associated with a management center (MC). Obtaining cryptographic information for encrypting specific data corresponding to the first user from a server associated with a key distribution center (KDC),
Generate a public key and an anonymous ID for the first user based on the obtained cryptographic information,
Generate a cipher text based on the specific data and the public key,
Generate a message authentication code based on the anonymous ID,
A computer-readable storage medium having recorded thereon a program for controlling a cryptographic system such that the anonymous ID, the cipher text, and the message authentication code are transmitted to a server associated with a management center (MC).

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