KR102330005B1 - Hybrid blockchain system for efficient content change and deletion and XGS injection method using hybrid blockchain - Google Patents

Abstract

The present invention discloses a hybrid blockchain system for efficient content change and deletion and an XGS injection method using a hybrid blockchain. A hybrid blockchain system for efficient content change and deletion according to an aspect of the present invention includes: Off Blockchain for storing original data; and On Blockchain, which records the metadata values linked only in the blockchain and holds them as a distributed general ledger.

Description

Hybrid blockchain system for efficient content change and deletion and XGS injection method using hybrid blockchain

The present invention relates to a hybrid blockchain system for efficient content change and deletion and an XGS injection method using a hybrid blockchain. More specifically, data is separated and connection history is stored in a blockchain, and state A hybrid blockchain system and hybrid blockchain for efficient content change and deletion that efficiently retrieves the history of correction and deletion of off-blockchain by changing state to a distributed database and randomly injecting in XOR (eXclusive OR) format It relates to an XGS injection method using

Recently, with the advent of Bitcoin, blockchain has been spotlighted as a database technology that provides integrity and reliability of the entire system by making it impossible to arbitrarily modify and delete as an addition-only distribution policy. Existing blockchain is a form of distributed ledger that records data in the blockchain as plain text (plaintext) or stores data in encrypted form with transactions and carries everything. However, since the blockchain is a CRAB (Create-Retrieve-Append-Burn) method that can read and write data according to a legitimate user's access rights (e.g., owner's private key) rather than modification or deletion, the above-mentioned blockchain-based In this method, since data cannot be deleted once created, problems such as infringement of personal information occur. In addition, Accenture's (a company in the US) Rewritable Blockchain makes it very difficult to find a common hash collision pair through a chameleon hash, but it uses a backdoor property to access the user's legitimate private key. It is easy to find conflicting pairs, where the contents of the transaction change but the hash value does not. Thus, the entire blockchain system is maintained and can be modified or deleted by legitimate users. However, if the original data disappears, there is a problem that the previous data cannot be accessed and it is difficult to track the data modification history.

Therefore, there is a need for research to solve the above-described problems in the prior art.

Korean Patent Registration No. 10-1964692 (published on April 2, 2019)

The present invention has been proposed to solve the above problems, and provides an on-off blockchain hybrid blockchain system that separates data and stores connection history in the blockchain, and distributes the state separately from the ledger record. Hybrid blockchain system and hybrid blockchain for efficient content change and deletion that can efficiently search the history of correction and deletion of off-blockchain by changing the database and changing the state by randomly injecting it in XOR (eXclusive OR) format An object of the present invention is to provide an XGS injection method using

Other objects and advantages of the present invention may be understood by the following description, and will be more clearly understood by an embodiment of the present invention. Further, it will be readily apparent that the objects and advantages of the present invention can be realized by the means and combinations thereof indicated in the claims.

A hybrid blockchain system for efficient content change and deletion according to an aspect of the present invention for achieving the above object includes: Off Blockchain for storing original data; and On Blockchain, which records the metadata values linked only in the blockchain and holds them as a distributed general ledger.

The off-blockchain and on-blockchain are characterized in that separate metadata databases are required for one blockchain connection.

The metadata is characterized in that it is composed of a hash value of data uploaded by the user and a name value of the user.

An XGS injection method using a hybrid block chain according to another aspect of the present invention for achieving the above object includes a pre-preparation step of building a database of data delegators including a function generated for smart contract-based block chain configuration; A user registration step of issuing a certificate for member confirmation in an authorized block chain and issuing a certificate of an elliptic curve-based key generation and authentication server; a data registration step of registering data by a data owner; a data correction and deletion step of correcting and deleting data of previously registered files; and a data retrieval step of tracking the state of the original data through a connection value of data generated by data registration, correction, and deletion.

The pre-preparation step identifies the modified file of the data owner by dividing the modified part of the previously registered file by 1, and calculates all null values by XOR operation with the previously registered file. XOR set (Set) extraction step; and a metadata generation step of generating metadata according to a name-value scheme.

The name of the metadata is characterized in that it is created by connecting the public key and the user's state value.

The generated function is characterized in that it includes a user registration function, a validation function, a data registration function, a data modification function, a data deletion function, and a transaction creation function.

Building the database of the data delegator is characterized by generating an XOR set (Set) and metadata.

The data modification and deletion step includes modification and deletion of XOR data, change and change of global state injection in off-blockchain, on-off linking, and on-chain transaction distribution. do.

The data correction and deletion step is characterized in that the binary data of the transformed part is changed to 1 according to the characteristics of XOR, and binary data identical to the data is extracted in the deletion step and changed to a null state.

According to one aspect of the present invention, off-block by separating data, storing connection history in the blockchain, changing the state to a distributed database separately from the ledger record, and changing the state by randomly injecting it in the XOR (eXclusive OR) format It has the effect of efficiently searching the history of correction and deletion of the chain.

The effects obtainable in the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those of ordinary skill in the art to which the present invention belongs from the following description. .

The following drawings attached to this specification illustrate preferred embodiments of the present invention, and serve to further understand the technical spirit of the present invention together with specific contents for carrying out the invention, so the present invention is in such drawings It should not be construed as being limited only to the items listed.
1 is a schematic configuration diagram of a hybrid blockchain system according to an embodiment of the present invention;
2 is a diagram showing a schematic configuration of a hybrid blockchain system according to an embodiment of the present invention;
3 is a diagram showing the connection of an on-off block chain according to an embodiment of the present invention;
4 is a diagram schematically illustrating injection of XGS according to an embodiment of the present invention;
5 is a diagram showing the configuration of a participating entity according to an embodiment of the present invention;
6 is a diagram schematically illustrating an XGS injection method using a hybrid block chain according to an embodiment of the present invention;
7 is a diagram illustrating extraction of an XOR set according to an embodiment of the present invention.

The above-described objects, features and advantages will become more apparent through the following detailed description in relation to the accompanying drawings, and accordingly, those of ordinary skill in the art to which the present invention pertains can easily implement the technical idea of the present invention. There will be. In addition, in the description of the present invention, if it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the accompanying drawings.

Throughout the specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated. In addition, the “… The term “unit” means a unit that processes at least one function or operation, which may be implemented as hardware or software or a combination of hardware and software.

1 is a schematic configuration diagram of a hybrid blockchain system according to an embodiment of the present invention, FIG. 2 is a diagram showing a schematic configuration of a hybrid blockchain system according to an embodiment of the present invention, and FIG. 3 is the present invention Fig. 4 is a diagram schematically explaining the injection of XGS according to an embodiment of the present invention, and Fig. 5 is an embodiment of the present invention. It is a diagram showing the configuration of participating entities according to

1 to 2 , the hybrid blockchain system according to the present embodiment includes a user device 100 , an Off blockchain 200 , and an On blockchain 300 .

Meanwhile, in describing the present embodiment, the off-blockchain 200 and the on-blockchain 300 may be in the form of a server.

The user device 100 may be a terminal of a data owner who owns the original data. The user device 100 transmits the original data to the off-blockchain 200 to be described later.

Off Blockchain (Off Blockchain) 200 stores the original data received from the user device (100). The off-blockchain 200 may include an authentication server, a database, and storage, and may serve as a data delegator.

On Blockchain 300 records the metadata values linked only in the blockchain and holds them as a distributed general ledger.

On the other hand, Off Blockchain 200 and On Blockchain 300 require a separate metadata database for one block chain connection. As shown in FIG. 3 , the metadata includes a hash value of data (file) uploaded by a user and a NAME value of the user. Name data (NAME data) is generated by connecting the user's public key and index number according to the state according to the name value method. This block is included in the On Blockchain (300). It is possible to provide an index for querying the Off Blockchain (200) of data in the On Blockchain (300) later.

Ethereum and Hyperledger record the latest state of recent transactions in the form of a distributed database with an irreversible ledger on the blockchain. Therefore, transactions included in the existing blockchain may appear to have been modified or deleted according to the latest state changes. Therefore, in the present invention, an arbitrary transaction injection is injected to redefine and modify XOR-based data through the above-described properties and then change the state of the On Blockchain 300 . A distribution database of XOR Global State (XGS) may be configured as shown in FIG. 4 . It is composed of key-values according to the XOR set. It is injected into the global state by the changed value of the data to be modified or deleted, and the global state of the Off Blockchain 200 is artificially changed. The On Blockchain 300 including the linking value is created, and the tracking of the On Blockchain 300 of the link value of the modified file is the reference value before the modification. (reference value) can be traced.

According to the present invention, a participating entity may be composed of a user who owns a data source and a data delegator, as shown in FIG. 5, and the data delegator is an authentication server, off storage, and database. ) may be included.

6 is a diagram schematically explaining an XGS injection method using a hybrid block chain according to an embodiment of the present invention, and FIG. 7 is a diagram explaining extraction of an XOR set according to an embodiment of the present invention.

Referring to FIG. 6 , the method according to the present embodiment includes a preliminary preparation step, a user registration step, a data registration step, and a data modification and deletion step. deletion step) and data retrieval step.

The pre-preparation stage includes functions created for smart contract-based blockchain configuration (including user registration function, validation function, data registration function, data modification function, data deletion function, and transaction creation function), This may include building the delegate's database (creating XOR sets and metadata).

The user registration step is a certificate issuance step for member verification in an authorized block chain, and may include elliptic curve-based key generation and certificate issuance of the authentication server.

The data registration step is a step of registering data by the data owner. This phase (data registration phase) includes data registration, off-link and off-chain on-chain transaction distribution.

The data modification and deletion step is a step of modifying and deleting data of a previously registered file. Includes modification and deletion of XOR data, injection and change of global state injection in Off Blockchain, On-Off Linking and distribution of on-chain transactions. can do. In the data modification step, the binary data of the transformed part is changed to 1 according to the characteristics of XOR, and in the deletion step, binary data identical to the data is extracted and changed to a null state.

In the data retrieval stage, the state of the original data can be tracked through the connection values of data created by data registration, modification, and deletion.

below. The above-described steps will be described in more detail.

A. Preparatory Steps

1) XOR set extraction

In the XOR (Exclusive OR) logical operation, if binary bits are the same in two-bit operation, it is calculated as 0, otherwise it is calculated as 1. Using this attribute, the modified file of the content owner (data owner) is identified by dividing the modified portion of the previously registered file by one. In addition, deletion is set to 0, and all null values are calculated by XOR operation with previously registered files. Accordingly, a state such as deletion is created. The definition of XOR set extraction is as follows. Fragments of column K consist of the values of V and are extracted from N (see Figure 7).

Here, K is the column key, V is the extracted XOR value, and N is the latest state.

The V extraction of the XOR set is divided into several fragments according to the index k of the previous state S in column K.

Here, k belongs to K (k ∈K), and S is the previous state.

According to the XOR set (Set), the N in the new shape state is extracted from the F in the old state. According to the XOR property, it consists of 1 in the modified position and 0 in the original.

2) Create metadata

Metadata is created according to the name-value scheme, and the name is created by connecting the public key and the user's state value. According to the state of data, the state value is assigned as a name value by concatenating the public key with 1 for registration, 2 for modification, and 0 for deletion. Thus, the value is linked to the hash value and name corresponding to the original data.

B. User Registration Steps

STEP 1. The user selects a random number SK _USER from prime number n.

STEP 2. Generate _{public key PK UESR} through n-group multiplicative group generator G through _{SK USER.}

STEP 3. The user _{registers the public key PK USER} in the authentication server and requests certificate issuance.

STEP 4. The authentication server selects a random number K from [1, n-1].

STEP 5. The authentication server selects a point (X1, Y1)=K*G on the elliptic curve, calculates r=X1 mod n, and selects k again if r=0.

STEP 6. The authentication server calculates the certificate message e=hash(m) including the user's public key.

STEP 7. The authentication server calculates S=k-1(e+SK _CA ) mod n and returns it to the user along with the signature (R, S).

STEP 8. The user verifies the signature of the certificate.

C. Data Registration Step

At this stage, the user registers data in a separate blockchain off-storage. A user performs authentication through a certificate-based private key using a CA (Certificate Authority) of a permissioned blockchain. Legitimate users register their data.

STEP 1. The user registers data with a signature to the data delegator.

STEP 2. The data source is stored in the off-storage of the data delegator, and metadata, which is data identification information, is created and stored in the database.

(H(D)||1||

STEP 3. Generate a transaction through smart contract distribution and creation.

STEP 4. Using the data registration function call (refer to the formula below) as an argument, verify the return value. If true, proceed to the next step.

STEP 5. Verifies the return value by taking the transaction signature verification and user public key verification (refer to the formula below) as arguments. If true, create a transaction.

D. Data Correction Steps

In this step, when a user requests to modify previously registered data, the user registers the data to be modified. It is composed of a key value according to the XOR set, and is injected into the global state using a binary value set to 1 as much as the modified value of the data to be modified, and the global state of the release blockchain (global state) is changed to artificial (artificial). Currently, On Blockchain transactions occur only when valid smart contracts such as the server's signature and the user's signature are validated.

STEP 1. The user registers the modified data with the signature to the data delegator.

STEP 2. The data delegator calculates an XOR set from the data modified by the user and extracts the modified part among the previously registered data. The binary data of the modified part of the newly modified file from the old state, which is the state of the pre-registered data, is set to K as a key S(K), and an XOR set of version N is generated.

STEP 3. The data delegator changes the global state by XORing the XOR set with the current state.

STEP 4. The data delegator creates injection metadata for on-chain linking according to the off-chain global state change.

Data||2||

(H(D)

Data||2||

STEP 5. Generate a transaction through smart contract deployment and creation.

STEP 6. Using the data registration function call (refer to the formula below) as an argument, verify the return value. If true, proceed to the next step.

STEP 7. Validate the return value by taking the transaction signature verification and user public key verification (refer to the formula below) as arguments. If true, create a transaction.

E. Data Deletion Steps

In this step, when the user requests to delete the pre-registered data, the data to be deleted is selected. It is composed of key-value according to the XOR set, and the data to be deleted is injected into the global state with the same XOR value as the pre-registered data, and Change the global state artificially. Currently, On Blockchain transactions occur only when valid smart contracts such as the server's signature and the user's signature are validated.

STEP 1. Delete data including data registration signature.

STEP 2. The data delegator calculates an XOR set from the user's deleted data using the same binary value as the pre-registered data. The binary data of the file deleted from the old state, which is the state of the pre-registered data, is set to K as the key S(K), and an XOR set of version N is created.

STEP 3. The data delegator changes the global state by XORing the XOR set with the current state.

STEP 4. The data delegator creates injection metadata for on-chain linking according to off-chain global state change.

Data||0||

(H(D)

Data||0||

STEP 5. Generate a transaction through smart contract deployment and creation.

STEP 6. Using the data registration function call (refer to the formula below) as an argument, verify the return value. If true, proceed to the next step.

STEP 7. Validate the return value by taking the transaction signature verification and user public key verification (refer to the formula below) as arguments. If true, create a transaction.

F. Data Retrieval Step

At this stage, content is tracked and viewed through a hybrid blockchain. Through this, it is possible to inquire the status of content registration, modification, and deletion.

STEP 1. Users search for content metadata through On Blockchain.

STEP 2. The metadata of the content is the lower leaf node of the On Blockchain to verify the root value of the merge tree.

= h((

)||(

))

= h((

)||(

)))

=

=

Meta Data =

,

,

STEP 3. If the root value of the on blockchain is valid, the metadata linking value is verified in the off blockchain.

STEP 4. The content provider checks the Name-Value of the linking value linked to the off-site database.

On the other hand, according to the present invention as described above, the following results can be obtained.

- Authentication: Provides user authentication according to the access of the user's public key and the corresponding private key, and provides message authentication through metadata including hash values.

- Reliability: Provides solid integrity through the decentralized chain network of the blockchain to ensure the reliability of the entire network.

- Efficiency: Instead of a linear search, an XGS-based index is added to search, and an On Blockchain is configured to perform an effective search.

-Privacy: The original data is stored in a separate off-blockchain, and only metadata is registered in the on-blockchain to protect the privacy of the data source. In addition, the user performs modifications and deletions.

- Traceability: Instead of completely disappearing the original data, it is possible to inquire and trace the status (registration, modification, deletion) of the original data by modifying or deleting the XOR data.

Methods according to an embodiment of the present invention may be implemented as an application or implemented in the form of program instructions that may be executed through various computer components and recorded in a computer-readable recording medium. The computer-readable recording medium may include program instructions, data files, data structures, etc. alone or in combination. The program instructions recorded on the computer-readable recording medium are specially designed and configured for the present invention, and may be known and used by those skilled in the art of computer software. Examples of the computer-readable recording medium include a hard disk, a magnetic medium such as a floppy disk and a magnetic tape, an optical recording medium such as a CD-ROM, a DVD, and a magneto-optical medium such as a floppy disk. media) and hardware devices specially configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine language codes such as those generated by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like. The hardware device may be configured to operate as one or more software modules to perform processing according to the present invention, and vice versa.

While this specification contains many features, such features should not be construed as limiting the scope of the invention or the claims. Also, features described in individual embodiments herein may be implemented in combination in a single embodiment. Conversely, various features described in a single embodiment herein may be implemented in various embodiments individually, or may be implemented in appropriate combination.

Although operations have been described in a particular order in the drawings, it should not be understood that such operations are performed in the specific order as illustrated, or that all described operations are performed in a continuous sequence, or to obtain a desired result. Multitasking and parallel processing can be advantageous in certain circumstances. In addition, it should be understood that the division of various system components in the above-described embodiments does not require such division in all embodiments. The app components and systems described above may generally be implemented as a package in a single software product or multiple software products.

The present invention described above, for those of ordinary skill in the art to which the present invention pertains, various substitutions, modifications and changes are possible without departing from the technical spirit of the present invention. It is not limited by the drawings.

100: user device
200: Off blockchain
300: On blockchain

Claims (10)

delete delete delete Pre-preparation step of building a database of data delegators including functions created for smart contract-based blockchain configuration in off-chain;
A user registration step of issuing a certificate for member confirmation in the blockchain allowed in the off-blockchain and on-blockchain, generating an elliptic curve-based key and using the certificate of the authentication server;
a data registration step of registering data of a data owner from the user device;
a data modification and deletion step of modifying and deleting data of previously registered files of the off-blockchain from the user device; and
A data retrieval step of tracking the state of original data in off-blockchain and on-blockchain through the connection values of data generated by data registration, modification, and deletion; XGS injection method using a hybrid blockchain comprising a. 5. The method of claim 4,
The pre-preparation step is
Identifies the modified file of the data owner by dividing the modified part of the previously registered file by 1, and extracts an XOR set that calculates all null values by XOR operation with the previously registered file step; and
An XGS injection method using a hybrid block chain, comprising: a metadata generation step of generating metadata according to a name-value scheme. 6. The method of claim 5,
An XGS injection method using a hybrid blockchain, characterized in that the name of the metadata is created by connecting the public key and the user's state value. 5. The method of claim 4,
The generated function is an XGS injection method using a hybrid blockchain, characterized in that it includes a user registration function, a validation function, a data registration function, a data modification function, a data deletion function, and a transaction creation function. 5. The method of claim 4,
Building a database of the data delegator comprises:
An XGS injection method using a hybrid block chain, characterized in that it generates an XOR set and metadata. 5. The method of claim 4,
The data modification and deletion steps include:
XGS injection using hybrid blockchain, characterized by including modification and deletion of XOR data, change and change of global state injection in off-chain, on-off linking, and on-chain transaction distribution Way. 5. The method of claim 4,
The data modification and deletion steps include:
An XGS injection method using a hybrid blockchain, characterized in that the binary data of the transformed part is changed to 1 according to the characteristics of XOR, and the same binary data as the data is extracted in the deletion step and changed to a null state.

Images