KR20190116838A - Security method and system for crypto currency - Google Patents

Abstract

The present invention relates to a cryptocurrency security method for preventing leakage of a private key to block cryptocurrency from being extorted and a system thereof. The cryptocurrency security system synchronizing with a cryptocurrency transaction system including an exchange server and a key storage to enhance security of a private key of a subscriber comprises: a hardware security module which encrypts or decrypts a subscriber private key by using a secret key in possession; and a key management server which stores the subscriber private key encrypted in the hardware security module in the key storage, provides the encrypted subscriber private key stored in the key storage to the hardware security module when electronic signature for a cryptocurrency transaction is received from the exchange server, and receives transaction information having electronic signature with the decrypted subscriber private key from the hardware security module to provide the received and electronically signed transaction information to the exchange server.

Description

Security method and system for crypto currency}

The present invention relates to a technique for improving the security of cryptocurrency, and more particularly, to a cryptocurrency security method and system that prevents the leakage of a private key to block the taking of cryptocurrency.

Cryptocurrency represented by Bitcoin is recognized as a borderless currency, and the number of available places (eg, offline stores, online stores, etc.) is increasing. The cryptocurrency is exchanged for real currency, and its value may change from time to time. Accordingly, investors may connect to an exchange server that can trade cryptocurrencies, and buy and sell cryptocurrencies.

In order to provide a cryptocurrency trading service for a customer, the exchange server manages a database in which a customer's cryptocurrency deposit address and balance are stored. In addition, the exchange server maps the customer's private key and cryptocurrency address and stores them in a key storage managed directly by the exchange.

When the exchange server trades cryptocurrencies between users, in order to generate a transaction, the exchange server propagates the transaction information including the electronic signature value and the public key, which digitally signed the transaction information with the private key, to the blockchain network. Transaction information propagated to the blockchain network is verified by neighboring nodes, and when the verification is successful, the transaction information is recorded and stored in the blockchain ledger.

However, when the private key is stolen from the key storage of the exchange server, ownership of the cryptocurrency may be changed to another person. Of course, the blockchain remains transaction information indicating that the ownership of the cryptocurrency has been changed to others, but there is a problem that it is very difficult to identify the actual criminal who seized the cryptocurrency in the cryptocurrency transaction that guarantees anonymity. In other words, if the private key is taken from the key storage of the exchange server and the ownership of the cryptocurrency is transferred to another person, transaction information resulting from the transfer of ownership is recorded on the blockchain, and the actual user who owns the cryptocurrency can be identified in the real world. There is no problem.

For this reason, exchanges should strengthen their security so that their private keys are not stolen by outside attackers, and must be managed so that they cannot be leaked or used outside by the internal employees.

The present invention has been proposed to solve such a conventional problem, and an object of the present invention is to provide a cryptocurrency security method and system that can prevent leakage of a private key without causing inconvenience to customers in cryptocurrency transactions.

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

In accordance with a first aspect of the present invention for achieving the above object, a cryptocurrency security system that improves the security of a subscriber's private key in conjunction with a cryptocurrency trading system including an exchange server and a key store, utilizes a secret key that is held. A hardware security module for encrypting or decrypting the subscriber private key; And storing the subscriber private key encrypted by the hardware security module in the key store, and receiving an electronic signature for a cryptocurrency transaction from the exchange server, and receiving the encrypted subscriber private key stored in the key store in the hardware security module. And a key management server configured to receive transaction information electronically signed with the decrypted subscriber private key from the hardware security module and provide the received electronically signed transaction information to the exchange server.

The hardware security module, upon receiving the subscriber private key encrypted with the secret key from the key management server, decrypts the subscriber private key encrypted with the secret key using the secret key, and the transaction information with the decrypted subscriber private key. Can be electronically signed.

The hardware security module receives the transaction information encrypted with its public key from the key management server, decrypts the transaction information encrypted with the public key using its private key, and decrypts the decrypted transaction information with the private key. Digitally sign with subscriber private key.

Meanwhile, the key management server transmits a message inquiring whether to approve the transaction to the terminal of the subscriber who performs the cryptocurrency transaction, and when a positive response to the message is received, the key management server interworks with the hardware security module to provide the subscriber private key. Electronically signed transaction information may be received and provided to the exchange server.

When the key management server receives a request for encryption of the subscriber private key from the exchange server, the key management server acquires the subscriber private key encrypted with the secret key in association with the hardware security module, and stores an existing subscriber private key stored in the key store. The subscriber private key encrypted with the secret key is stored in the key store.

The key management server may receive a type of cryptocurrency to be traded from the exchange server, check an algorithm for an electronic signature corresponding to the type of cryptocurrency, and provide the same to the hardware security module.

In the cryptocurrency security system according to the first aspect of the present invention for achieving the above object, a method for improving the cryptocurrency security by preventing the takeover of subscriber private key, the key management server, in conjunction with the hardware security module, Storing the encrypted subscriber private key in the key store in the hardware security module; When the key management server receives an electronic signature for a cryptocurrency transaction from an exchange server, the key management server provides the encrypted subscriber private key to the hardware security module to provide transaction information electronically signed with a decrypted subscriber private key. Receiving from; And providing, by the key management server, the received electronically signed transaction information to the exchange server.

The present invention has the advantage of preventing the seizure of the customer's cryptocurrency by blocking the private key leakage at the source in the transaction of the cryptocurrency.

In addition, the present invention by storing the encrypted private key on the exchange, even if the exchange system is hacked can not use the private key, it is possible to prevent the situation that the cryptocurrency is seized.

In addition, since the present invention decrypts the encrypted private key every time a transaction occurs in the hardware security module, and digitally signs the transaction information with the private key, the present invention has the advantage of protecting the private key more securely from external attacks. have.

In addition, the present invention has an advantage that the electronic security signature for the transaction information is carried out whenever necessary, using a hardware security module, compared to the existing exchange system, does not compromise the convenience in trading virtual currency.

In addition, the present invention has an effect of further strengthening the security against cryptocurrency trading since the authorization authentication is performed using the user's e-mail, mobile phone number, and the like when the electronic signature is required.

The following drawings attached to this specification are illustrative of the preferred embodiments of the present invention, and together with the specific details for carrying out the invention serve to further understand the technical spirit of the present invention, the present invention described in such drawings It should not be construed as limited to matters.
1 is a diagram showing a cryptocurrency security system according to an embodiment of the present invention.
2 is a flowchart illustrating a method of replacing a subscriber private key stored in a key store with an encrypted subscriber private key in a cryptocurrency security system according to an embodiment of the present invention.
3 is a flowchart illustrating a method of distributing electronically signed transaction information in a cryptocurrency security system according to an embodiment of the present invention.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, whereby those skilled in the art may easily implement the technical idea of the present invention. There will be. In addition, in describing the present invention, when 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, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram showing a cryptocurrency security system according to an embodiment of the present invention.

As shown in FIG. 1, a cryptocurrency security system according to an embodiment of the present invention includes a hardware security module (Hardware Security Module, hereinafter referred to as 'HSM') 100, a key management server 200, an exchange server ( 300, a key store 400, and a blockchain network 500, which components can communicate with each other over a public network or with each other over a dedicated line.

The HSM 100 is a hardware security module that generates keys in hardware and encrypts or decrypts data. The HSM 100 may be implemented as one independent device or may be mounted on another server or device. In particular, the HSM 100 generates a public key (hereinafter referred to as an 'HSM public key') and a private key (hereinafter referred to as an 'HSM private key') and retains the HSM private key without sharing it. Distribute and share the HSM public key with other devices. In addition, the HSM 100 stores a secret key which is a symmetric key, and only owns the secret key without sharing it with another server or device. When the HSM 100 receives a request for encryption of a subscriber's private key (hereinafter referred to as a subscriber's private key) from the key management server 200, the HSM 100 encrypts the subscriber's private key with a secret key to manage the key management server 200. To send. At this time, if the subscriber private key is encrypted with the HSM public key, the HSM 100 decrypts the subscriber private key with the HSM private key and then encrypts the decrypted subscriber private key using the secret key.

In addition, when the HSM 100 receives an electronic signature request from the key management server 200, the HSM 100 decrypts the encrypted transaction information received from the key management server 200 using the HSM private key, and the key management server 200. The encrypted subscriber private key received from the device is decrypted with the secret key. In addition, the HSM 100 electronically signs the transaction information using the subscriber private key using the decrypted subscriber private key and the decrypted transaction information, and then transmits the electronically signed transaction information to the key management server 200. send.

The key store 400 is a storage means such as a database and a disk device, and stores a private key for each subscriber. In particular, the key store 400 deletes the unencrypted subscriber private key and stores the subscriber private key encrypted with the HSM secret key instead of the deleted subscriber private key.

The exchange server 300 is a system that supports cryptocurrency transactions between subscribers, and stores and manages subscriber information such as subscriber's email address, subscriber ID, subscriber mobile phone number, subscriber name, address, date of birth, and the like. The exchange server 300 stores and manages the storage environment of each subscriber private key for each subscriber. In particular, the exchange server 300 updates the storage environment of the encrypted subscriber private key when the original subscriber private key (that is, the unencrypted subscriber private key) is replaced with the encrypted subscriber private key in the key storage 400. . The exchange server 300 may interwork with the key management server 200 to obtain a subscriber private key encrypted with the HSM secret key. In addition, the exchange server 300 distributes blockchain-based transaction information to the blockchain network 500 when a transaction of cryptocurrency proceeds. In addition, the exchange server 300 receives the electronically signed transaction information from the key management server 200 in cooperation with the key management server 200.

The blockchain network 500 is connected to a plurality of nodes, and the transaction verification of the transaction information is performed. In addition, nodes belonging to the blockchain network 500 share a blockchain having a transaction book (that is, transaction information) and having a connection structure between blocks.

The key management server 200 interoperates with the HSM 100 and the exchange server 300 to discard the original subscriber private key stored in the key storage 400 and replace the original subscriber private key in the HSM 100. The encrypted subscriber private key is stored in the key storage 400. In addition, when the key management server 200 receives an electronic signature request from the exchange server 300, the key management server 200 receives the electronically signed transaction information from the HSM 100, and provides the electronically signed transaction information to the exchange server 300. . The key management server 200 stores different digital signature algorithms for each type of cryptocurrency, identifies the type of cryptocurrency that is the subject of a transaction, and provides the electronic signature algorithm corresponding to the type to the HSM 100. . After the key management server 200 sends a message to the subscriber requesting a response to the transaction approval, if the response to the message is positive, the key management server 200 may selectively transmit the electronically signed transaction information to the exchange server 300. have.

2 is a flowchart illustrating a method of replacing a subscriber private key stored in a key store with an encrypted subscriber private key in a cryptocurrency security system according to an embodiment of the present invention.

2, the exchange server 300 confirms the subscriber's identification information subscribed to the cryptocurrency security service according to the present invention, and stores the subscriber's private key mapped to the identification information (ie, file name and storage path name). ). The exchange server 300 accesses the key storage 400 based on the storage environment to obtain a subscriber private key (S201). Subsequently, the exchange server 300 checks subscriber information mapped to the subscriber's private key (S203). The subscriber information includes a subscriber's e-mail address, mobile phone number, subscriber ID, etc. for performing transaction approval authentication.

Next, the exchange server 300 encrypts the subscriber's private key with the public key of the HSM (S205). At this time, when the private key of the subscriber is encrypted, the exchange server 300 discards the original subscriber private key (ie, unencrypted subscriber private key) obtained from the key storage 400 in storage means such as a memory or a disk device. The trace on the original subscriber private key is completely removed from the exchange server 300. The exchange server 300 requests the key management server 200 to encrypt the subscriber private key (S209). In this case, the exchange server 300 transmits not only the subscriber private key encrypted with the HSM public key, but also the storage environment information and the subscriber information of the subscriber private key to the key management server 200. Then, the key management server 200 temporarily stores the encrypted subscriber private key, subscriber private key storage environment information and subscriber information, and transmits the subscriber private key encrypted with the HSM public key to the HSM 100 to the subscriber private key. Request encryption of (S209).

Subsequently, the HSM 100 decrypts the subscriber private key encrypted with the HSM private key (S211). In addition, the HSM 100 encrypts the subscriber private key by using the private key stored in the self (S213). The HSM 100 does not store the decrypted subscriber private key separately, and immediately discards the subscriber private key when encryption of the subscriber private key is completed and completely removes traces of the subscriber private key from storage means such as a memory. do. Subsequently, the HSM 100 transmits the encrypted subscriber private key to the key management server 200 (S215).

Next, the key management server 200 maps and stores the subscriber information and the subscriber private key encrypted with the secret key (S217). The key management server 200 deletes the subscriber private key encrypted with the HSM public key received from the exchange server 300. Subsequently, the key management server 200 provides the personal storage environment information to the key store 400 to request the deletion of the subscriber private key (ie, the unencrypted private key) stored in the key store 400, The key store 400 deletes the subscriber private key that matches the storage environment information (S219). Subsequently, the exchange server 300 stores the subscriber private key encrypted with the HSM secret key in the key storage 400 (S221). That is, the exchange server 300 deletes the original subscriber private key (ie, unencrypted subscriber private key) stored in the key storage 400, and replaces the original subscriber private key with the private key encrypted with the HSM secret key. Store in the storage 400. The exchange server 300 may check the storage environment information (ie, the file name and the storage path name) of the subscriber private key encrypted with the HSM secret key, and transmit the storage environment information of the subscriber private key to the exchange server 300. Then, the exchange server 300 changes the storage environment information of the existing subscriber private key stored in the storage environment information received from the key management server 200.

In another embodiment, when the key management server 200 cannot access the key store 400 in a network environment, the key management server 200 directly stores the subscriber private key encrypted with the HSM secret key. ), The subscriber private key encrypted with the HSM secret key may be provided to the exchange server 300. In this case, the exchange server 300 deletes the original subscriber private key (that is, the unencrypted subscriber private key) stored in the key storage 400, and stores the subscriber private key encrypted with the HSM secret key in the key storage 400. Save it. The exchange server 300 checks the storage environment information for the subscriber private key encrypted with the HSM secret key, and updates the storage environment information of the subscriber private key stored previously with the checked storage environment information.

According to this procedure, the original subscriber private key is not stored anywhere, and the subscriber private key encrypted with the HSM secret key is stored in the key storage 400. Therefore, even if the subscriber private key is stolen from the key storage 400, the encrypted subscriber private key cannot be used in cryptocurrency transactions.

3 is a flowchart illustrating a method of distributing electronically signed transaction information in a cryptocurrency security system according to an embodiment of the present invention.

Referring to FIG. 3, the exchange server 300 receives transaction information about a specific type of cryptocurrency from a subscriber. For example, the exchange server 300 may receive a type of cryptocurrency such as Bitcoin, Ethereum, etc. from the subscriber, and receive transaction information including counterpart information that is a transaction amount of the cryptocurrency from the subscriber. Then, the exchange server 300 checks the subscriber private key storage environment that is mapped to the subscriber's identification information in order to perform the transaction of cryptocurrency, and the subscriber's personal in the key storage 400 based on the private key storage environment. Obtain a key (S301). Here, the subscriber private key is encrypted with the HSM secret key.

Next, the exchange server 300 encrypts the transaction information using the HSM public key, and sends the electronic signature request message including the encrypted transaction information, the subscriber private key, and the cryptocurrency type to the key management server 200. It transmits (S303).

Subsequently, the key management server 200 confirms subscriber information mapped to the encrypted subscriber private key, and checks an email address or a mobile phone number necessary for transaction approval authentication in the subscriber information (S305). Subsequently, the key management server 200 creates a message requesting authentication for transaction approval, sets the called party number of the message as the e-mail address and the mobile phone number, and sends the message (S307). For example, the key management server 200 may send a message to the subscriber, such as "Request a transaction approval for virtual currency. Please enter '1' or '0' to proceed with the transaction of the cryptocurrency."

The key management server 200 receives a response to the message from the terminal of the subscriber (S309), and if the response is a non-tradeable response, notifies the exchange server 300 that the electronic signature cannot be performed, and the exchange server 300 ) Stops the requested transaction.

On the other hand, upon receiving a transaction approval response as a response to the message from the terminal of the subscriber, the key management server 200 checks the electronic signature algorithm corresponding to the cryptocurrency type (S311). The key management server 200 transmits the electronic signature request message including the confirmed electronic signature algorithm, the encrypted transaction information, and the subscriber private key encrypted with the HSM secret key to the HSM 100 (S313).

Then, the HSM 100 extracts the subscriber private key encrypted with the electronic signature algorithm, the encrypted transaction information and the HSM secret key from the electronic request message, and decrypts the encrypted subscriber private key using the HSM secret key ( S315). In addition, the HSM 100 decrypts the transaction information encrypted with the HSM public key using the HSM private key (S317). When the decryption is completed, the HSM 100 electronically signs the transaction information using the subscriber private key using the decrypted subscriber private key and the decrypted transaction information, and then electronically signs the transaction information on the key management server. And transmits to S200 (S319 and S321). At this time, the HSM 100 performs an electronic signature on the transaction information by using the electronic signature algorithm received from the key management server 200. In addition, the HSM 100 does not store the decrypted subscriber private key separately and immediately discards the electronic subscriber signature, thereby removing traces of the subscriber private key from the memory.

Next, the key management server 200 transmits the electronically signed transaction information to the exchange server 300 (S323).

Then, the exchange server 300 propagates the blockchain-based transaction information including the electronically signed transaction information to the blockchain network (S325). The electronically signed transaction information is verified by other nodes in the blockchain network 500, and if the verification is successful, a new block containing the transaction information is connected (ie, chained) to an existing block, and the blockchain is Is expanded.

As described above, the cryptocurrency security system according to the present invention prevents a customer's cryptocurrency from being seized by blocking the private key leakage at the source in the transaction of the cryptocurrency. In addition, the cryptocurrency security system according to the present invention, by storing the encrypted private key on the exchange, even if the data of the key storage 400 is hacked, it is impossible to use the private key.

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

Although the operations are described in a particular order in the drawings, they should not be understood as being performed in a particular order as shown, or in a sequence of successive orders, or all described actions being performed to obtain a desired result. . Multitasking and parallel processing may 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 program components and systems described above may generally be packaged in a single software product or multiple software products.

The method of the present invention as described above may be implemented as a program and stored in a recording medium (CD-ROM, RAM, ROM, floppy disk, hard disk, magneto-optical disk, etc.) in a computer-readable form. Since this process can be easily implemented by those skilled in the art will not be described in more detail.

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

100: HSM
200: key management server
300: Exchange Server
400: Key Store
500: blockchain network

Claims (9)

A cryptocurrency security system that improves the security of a subscriber's private key by interworking with a cryptocurrency trading system including an exchange server and a key storage,
A hardware security module for encrypting or decrypting the subscriber private key using the held secret key; And
The subscriber private key encrypted by the hardware security module is stored in the key store, and when the electronic signature for cryptocurrency transaction is requested from the exchange server, the encrypted subscriber private key stored in the key store is transferred to the hardware security module. And a key management server configured to receive transaction information electronically signed with the decrypted subscriber private key from the hardware security module and provide the received electronically signed transaction information to the exchange server. The method of claim 1,
The hardware security module,
When the private key encrypted with the secret key is received from the key management server, the private key encrypted with the private key is decrypted using the private key, and the transaction information is electronically signed with the decrypted subscriber private key. Cryptocurrency security system. The method of claim 2,
The hardware security module,
Receiving transaction information encrypted with its public key from the key management server, decrypting the transaction information encrypted with the public key using its private key, and electronically signing the decrypted transaction information with the decrypted subscriber private key Cryptocurrency security system, characterized in that. The method of claim 1,
The key management server,
Send a message inquiring whether to approve the transaction to the terminal of the subscriber performing the cryptocurrency transaction, and when a positive response to the message is received, the transaction information electronically signed with the subscriber private key in conjunction with the hardware security module to receive Cryptocurrency security system, characterized in that provided to the exchange server. The method of claim 1,
The key management server,
Upon receiving the request for encryption of the subscriber private key from the exchange server, the subscriber secures the subscriber private key encrypted with the secret key in association with the hardware security module, and encrypts the existing subscriber private key stored in the key storage with the private key. Cryptocurrency security system, characterized in that stored in the key storage by replacing with a private key. The method of claim 1
The key management server,
Receiving a type of cryptocurrency that is a transaction from the exchange server, the cryptographic security system, characterized in that to provide an electronic signature corresponding to the type of cryptocurrency to the hardware security module. In the cryptocurrency security system, to prevent the takeover of subscriber private key to improve the cryptocurrency security,
Storing, by a key management server, a subscriber private key encrypted in the hardware security module in a key store in association with a hardware security module;
When the key management server receives an electronic signature for a cryptocurrency transaction from an exchange server, the key management server provides the encrypted subscriber private key to the hardware security module to provide transaction information electronically signed with a decrypted subscriber private key. Receiving from; And
And providing, by the key management server, the received electronically signed transaction information to the exchange server. The method of claim 7, wherein
Receiving from the hardware security module,
The key management server transmits a message inquiring whether to approve the transaction to the terminal of the subscriber who performs the transaction, and when a positive response to the message is received, the key management server electronically signs the decrypted subscriber private key in association with the hardware security module. Cryptocurrency security method comprising receiving the transaction information provided to the exchange server. The method of claim 7, wherein
Storing the subscriber private key in a key store,
Receiving, by the key management server, encryption of the subscriber private key from the exchange server;
Acquiring, by the key management server, a subscriber private key encrypted with a secret key in association with the hardware security module; And
And replacing, by the key management server, an existing subscriber private key stored in the key store with a subscriber private key encrypted with the secret key.

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