KR102493093B1 - Apparatus and method for serving email service based on blockchain network - Google Patents

Abstract

An apparatus and method for providing a content-certified e-mail service based on blockchain are disclosed. The blockchain-based apparatus and method for providing content-certified e-mail service includes the steps of issuing an irreplaceable content-certificate token containing e-mail content encrypted by a symmetric key of a sender's terminal on a content-certified blockchain; Encrypting with the public key of the terminal so that it is recorded in the attribute information of the content-proof token on the content-proof blockchain, receiving a verification result of verifying the transmission history of the content-proof token transmitted by the sender terminal from the email transmission server and adding to the attribute information of the proof-of-contents token issued on the proof-of-content blockchain, receiving a verification result of verifying the transmission history of the proof-of-contents token sent by the email sending server from the email receiving server , recording in the attribute information of the proof of contents token issued on the proof of contents blockchain, and when receiving the proof of contents token from the email receiving server, using the symmetric key in the proof of contents token transmitted by the email receiving server It is possible to provide a high-efficiency, high-accuracy, high-reliability and low-cost block chain-based content-certification email service providing apparatus and method including the step of decrypting the encrypted email contents with a private key so that the recipient can read them.

Description

Apparatus and method for providing content-certified e-mail service based on blockchain {APPARATUS AND METHOD FOR SERVING EMAIL SERVICE BASED ON BLOCKCHAIN NETWORK}

The present invention relates to an apparatus and method for providing a blockchain-based content-certified e-mail service, and more particularly, an object thereof is to provide an apparatus and method for providing a blockchain-based content-certified e-mail service.

Content-certified mail is a system in which the post office, a nationally authorized institution, provides proof of the fact when the sender requests the recipient to notify or take action.

For content-certified mail, the postal service provides an authentication service to officially certify who the mail sender and recipient are, and if the sender and recipient send or receive the content-certified mail but deny it Provides non-repudiation proof services for

Since the contents-certified mail method through the post office uses paper documents, there is a disadvantage in that efficiency is low in terms of time and cost.

Today, e-mail service, which is used by most users to deliver information online, provides users with higher convenience by interlocking with services necessary for real life, such as address book and calendar, in addition to the main function of sending and receiving mail.

E-mail service is a distributed system that is interconnected based on open standard protocols on the Internet and has excellent scalability. Standard protocols for sending and receiving e-mails include Simple Mail Transfer Protocol (SMTP), Post Office Protocol 3 (POP3), and Internet Message Access Protocol (IMAP).

More specifically, when an e-mail client sender sends an e-mail, the e-mail is transmitted to the sender's e-mail server through the SMTP protocol, and the e-mail is transmitted from the sender's e-mail server to the recipient's e-mail server. Then, when the email transmission to the recipient's email server is completed, the email client recipient receives the email from the email server through the POP3 or IMAP protocol.

However, the open standard e-mail service (hereinafter referred to as @mail) commonly used by users in the past does not provide proof of e-mail content integrity, authentication of senders and receivers, and proof of preventing repudiation of actions by senders and receivers. There is a problem in that it is difficult to use as evidence information that is effective in transactions.

Accordingly, in recent years, shop mail (hereinafter referred to as #mail) service has been provided as an e-mail method to give legal effect online, such as a content-certified postal service.

Unlike the @mail address, the #mail service can be used only when a certified electronic address (#mail address) is issued in advance according to user identification.

In addition, relay services related to sending and receiving #mail are provided only through officially licensed certified electronic document brokers, and certified electronic document brokers store electronic document information sent and received on #mail and issue certificates if necessary. #Provides legally effective evidence for information delivered by e-mail.

However, since #mail has its own address system and protocol, it is not mutually compatible with @mail, which is commonly used by conventional users. For this, there is an inefficient problem in that @mail must be used additionally.

In addition, since the #mail service is based on its own protocol, the technology may be isolated compared to the @mail service, which is developing in various ways according to the development of open standard protocols. Again, since it cannot be used, there is a problem in that it inevitably reduces work inefficiency.
In this way, in the prior art, it is possible to verify the sender/receiver and the email content by guaranteeing the integrity of the contents of the transmitted/received email, and to provide evidence to prevent the denial of the act of sending/receiving. There is no proposed e-mail service that is compatible with the @mail method, or a device and method for providing such a service.

[Document 1] S. Hong, Y. Noh, and C. Park. Design of Extensible Non-Fungible Token Model in Hyperledger Fabric. 2019, In Proceedings of the 3rd Workshop on Scalable and Resilient Infrastructures for Distributed Ledgers, pp. 1-2. [Document 2] Hong Sang-won, Noh Yung-doo, Park Chan-ik. A Study on the Scalable Non-Fungible Token Framework for Hyperledger Fabric, 2019, Proceedings of the Korea Information Science Society, pp. 785-787.

An object of the present invention to solve the above problems is to ensure the integrity of e-mail contents so that it is possible to prove the sender/recipient and the e-mail contents, and to provide evidence to prevent the denial of sending/receiving acts, It is to provide a high-efficiency, high-accuracy, high-reliability, and low-cost block chain-based content-certification email service providing device that enables sending and receiving emails compatible with @mail of a universally used open standard method.

In addition, another object of the present invention to solve the above problems is to provide a high-efficiency, high-accuracy, high-reliability and low-cost blockchain-based content-certification e-mail service method.

According to an embodiment of the present invention for achieving the above object, an apparatus for providing a content-certified e-mail service based on a content-certified blockchain includes a memory and a processor executing at least one command stored in the memory. ), wherein the at least one command is a command for issuing an irreplaceable proof-of-contents token containing e-mail content encrypted by the symmetric key of the sender's terminal on the proof-of-contents blockchain; A command to encrypt with a public key and record it in the attribute information of the content-proof token on the content-proof block chain. When the email sending server receives the content-proof token from the sender terminal by protocol, the message sent by the user terminal A command for receiving the verification result of verifying the transmission history of the content proof token from the email sending server and adding it to the attribute information of the content proof token issued on the proof of content blockchain, the email receiving server, by means of a protocol When a content verification token is received from the e-mail transmission server, the verification result of verifying the transmission history of the content verification token transmitted by the e-mail transmission server is received from the e-mail reception server, and the content issued on the content verification blockchain is received. When a command to record in attribute information of a proof token and a recipient terminal receive a content proof token from the email receiving server by protocol, an email encrypted with the symmetric key in the content proof token sent by the email receiving server It includes a command to decrypt the content with a private key so that the recipient can view it.

In this case, the protocol may be an email protocol.

Also, the e-mail protocol may be any one of Simple Mail Transfer Protocol (SMTP), Post Office Protocol (POP3), and Internet Message Access Protocol (IMAP).

The sender terminal, the email sending server, the email receiving server, and the receiver terminal may be pre-registered in a proof-of-contents blockchain.

In addition, prior to a command for issuing an irreplaceable content-certification token containing e-mail content encrypted by the symmetric key of the sender terminal on the content-certification blockchain, the sender terminal, the e-mail sending server, the e-mail receiving server and A command for issuing a public key and a private key to the recipient terminal may be further included.

At this time, after the command to issue the public key and the private key, a command to store the public keys of the sender terminal, the email sending server, the email receiving server, and the recipient terminal, respectively, on the proof-of-contents blockchain can include more.

Here, the public key and the private key may be a public key infrastructure (PKI).

On the other hand, the command to receive the verification result of verifying the transmission history of the content proof token transmitted by the user terminal from the email transmission server and add it to the attribute information of the content proof token issued on the proof of content blockchain , an instruction for causing the e-mail transmission server to determine whether the e-mail address of the sender in the content-certification token issued on the content-certification network and the e-mail address of the sender terminal in the content-certification token received by the protocol match, and When the e-mail addresses match, record the proof value of the e-mail sending server, which signs the attribute information of the content proof token with the private key of the e-mail sending server, in the attribute information of the content proof token in the proof of content blockchain Can contain commands.

In addition, the verification result of verifying the transmission history of the content proof token transmitted by the email sending server is received from the email receiving server and recorded in attribute information of the content proof token issued on the proof of content blockchain The command causes the e-mail receiving server to determine whether the e-mail address of the sender in the content-certification token issued on the content-certification network and the e-mail address of the sender terminal in the content-certification token received by the protocol match; When the email addresses match, the public key of the email sending server is used to decrypt the proof value of the email sending server recorded in the proof of contents token on the proof of content blockchain to verify the email sending history. command and, when the e-mail transmission history is verified, a command to record the proof value of the e-mail receiving server that signed the added attribute information of the content-proof token with the private key of the e-mail receiving server in the attribute information of the content-proof token can include

In addition, the e-mail may be provided as an open standard e-mail (@mail).

According to another embodiment of the present invention for achieving the above object, a method for providing a content-certified e-mail service based on a content-certified blockchain is an irreplaceable content-certified token including e-mail content encrypted by a symmetric key of a sender terminal. issuing on the proof-of-contents blockchain, encrypting the symmetric key with the public key of the recipient's terminal, and recording it in the attribute information of the proof-of-contents token on the proof-of-contents blockchain; When the content verification token is received from the sender terminal, the verification result of verifying the transmission history of the content verification token transmitted by the user terminal is received from the email transmission server, and the contents verification token issued on the proof of contents blockchain adding to the attribute information of the token, a verification result of verifying the transmission history of the content verification token transmitted by the email transmission server when the email receiving server receives the content proof token from the email sending server through a protocol is received from the e-mail reception server and recorded in attribute information of the content-certification token issued on the content-certification blockchain, and when the recipient terminal receives the content-certification token from the e-mail reception server by protocol , decrypting the e-mail content encrypted with the symmetric key in the content-certification token transmitted by the e-mail receiving server with a private key so that the recipient can read it.

In this case, the protocol may be an email protocol.

Also, the e-mail protocol may be any one of Simple Mail Transfer Protocol (SMTP), Post Office Protocol (POP3), and Internet Message Access Protocol (IMAP).

The sender terminal, the email sending server, the email receiving server, and the receiver terminal may be pre-registered in a proof-of-contents blockchain.

In addition, prior to the step of issuing an irreplaceable content-certification token containing e-mail content encrypted by the symmetric key of the sender terminal on the content-certification blockchain, the sender terminal, the e-mail sending server, the e-mail receiving server and The method may further include issuing a public key and a private key to each of the recipient terminals.

In this case, after the issuing of the public key and the private key, the step of storing the public keys of the sender terminal, the email sending server, the email receiving server, and the recipient terminal, respectively, on the proof-of-content blockchain is further included. can do.

Here, the public key and the private key may be a public key infrastructure (PKI).

On the other hand, the step of receiving the verification result of verifying the transmission history of the content proof token transmitted by the user terminal from the email transmission server and adding it to the attribute information of the content proof token issued on the proof of content blockchain having the e-mail sending server determine whether the e-mail address of the sender in the content-certification token issued on the content-certification network and the e-mail address of the sender terminal that sent the content-certification token received by the protocol match. and if the e-mail addresses match, recording the proof value of the e-mail transmission server, which signed the attribute information of the content-proof token with the private key of the e-mail transmission server, in the attribute information of the content-proof token in the content-proof block chain. steps may be included.

In addition, the verification result of verifying the transmission history of the content proof token transmitted by the email sending server is received from the email receiving server and recorded in attribute information of the content proof token issued on the proof of content blockchain The step of causing the e-mail receiving server to determine whether the e-mail address of the sender in the content-certification token issued on the content-certification network and the e-mail address of the sender terminal in the content-certification token received by the protocol match; If the e-mail addresses match, verifying the e-mail transmission history by using the public key of the e-mail transmission server to decrypt the proof value of the e-mail transmission server recorded in the content-certification token on the content-certification blockchain. and when the e-mail transmission history is verified, recording a proof value of the e-mail receiving server that signed the added attribute information of the content-proof token with the private key of the e-mail receiving server in the attribute information of the content-proof token. can do.

In addition, the e-mail may be provided as an open standard e-mail (@mail).

The apparatus and method for providing a blockchain-based content-certification e-mail service according to an embodiment of the present invention is perfectly compatible with the @mail service, and depending on the purpose, the user may use a general @mail service or a content-certification @mail service. can optionally be used.

In addition, the present invention can completely replace the #mail service by solving inefficiencies such as high cost and user inconvenience of #mail service, which has a similar service built with its own protocol, and can completely replace #mail service provided by user authentication, confidentiality, Integrity and non-repudiation of sender and receiver characteristics can be satisfied through blockchain.

Since the sender terminal issues a content proof token on the blockchain based on the signature information, authentication of the sender terminal and the receiver terminal can be supported through the attribute information of the content proof token, and the integrity of the encrypted e-mail content can be guaranteed.

In addition, since the present invention can maintain confidentiality between end-to-end senders and receivers of transmitted e-mail information even in a distributed environment connected by the open standard @mail protocol, it can be applied to environments requiring very high confidentiality such as military or financial use.

In addition, by additionally recording the proof value, which is the signature information of the email sending server, in the content proof token issued by the sender terminal, it is possible to verify this and provide proof of non-repudiation of the act of sending the email. By recording the authentication value, which is the signature information of the e-mail reception server, in the attribute information of the e-mail reception server, it is possible to provide the user terminal with proof of preventing the rejection of the reception action.

1 is a block diagram of a blockchain-based content-certification e-mail service system according to an embodiment of the present invention.
2 is a block diagram for explaining hardware configurations of a blockchain-based content-certification e-mail service providing apparatus according to an embodiment of the present invention.
3 is a block diagram illustrating software configurations of an apparatus for providing a blockchain-based content-certification e-mail service according to an embodiment of the present invention.
4 is a block diagram illustrating an apparatus for providing a content-certified e-mail service based on a block chain according to an embodiment of the present invention.
5 is an image for explaining a data structure of a content proof token of a blockchain-based content proof email service providing device according to an embodiment of the present invention.
6 is a flowchart illustrating a method for providing a content-certified e-mail service using a blockchain-based content-certified e-mail service providing apparatus according to an embodiment of the present invention.

Since the present invention can make various changes and have various embodiments, specific embodiments will be illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. Like reference numerals have been used for like elements throughout the description of each figure.

Terms such as first, second, A, and B may be used to describe various components, but the components should not be limited by the terms. These terms are only used for the purpose of distinguishing one component from another. For example, a first element may be termed a second element, and similarly, a second element may be termed a first element, without departing from the scope of the present invention. The term “and/or” includes any combination of a plurality of related listed items or any of a plurality of related listed items.

It is understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, but other elements may exist in the middle. It should be. On the other hand, when an element is referred to as “directly connected” or “directly connected” to another element, it should be understood that no other element exists in the middle.

Terms used in this application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the terms "include" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and unless explicitly defined in the present application, they should not be interpreted in an ideal or excessively formal meaning. don't

The blockchain disclosed in the present invention is based on a P2P network, and a block composed of a set of transactions including the data of nodes participating in the proof-of-contents blockchain determines the hash value of the previous block. It is a data structure that contains and connects all blocks in the form of a chain, and is a Distributed Ledger Technology (DLT) in which all participating nodes maintain the same data structure based on a consensus algorithm.

In addition, even if the blockchain data of a specific node is arbitrarily manipulated, the manipulated data is not reflected in the blockchain because it is not agreed upon between the nodes, ensuring the integrity and transparency of the data.

Blockchain is divided into permissionless blockchain and permissioned blockchain. In the permissionless blockchain, users and nodes can participate in the proof-of-content blockchain without any restrictions, and in the permissioned blockchain, only authorized users and nodes can participate in the proof-of-content blockchain, which has the advantage of being suitable for use in a business environment. .

Distributed Applications (dApps) can be developed and operated by configuring business logic in smart contracts, which are programs that run on the blockchain. At this time, the smart contract has the advantage of automatically executing each request according to business logic without third party intervention. A representative App is Token.

The token disclosed in the present invention is a representation of a digital asset on a blockchain. Tokenizing digital assets on the blockchain provides advantages such as proof of ownership of digital assets, guaranteeing transparency, and improving liquidity. Tokens are divided into fungible tokens and non-fungible tokens. Here, the fungible token is a token representing a divisible digital asset, and the non-fungible token is a token representing an indivisible digital asset.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in more detail. In order to facilitate overall understanding in the description of the present invention, the same reference numerals are used for the same components in the drawings, and redundant descriptions of the same components are omitted.

1 is a block diagram of a blockchain-based content-certification e-mail service system according to an embodiment of the present invention.

Referring to FIG. 1, the blockchain-based content-certification e-mail service system includes a sender terminal 1000, a receiver terminal 2000, an e-mail transmission server 3000, an e-mail reception server 4000, and a content-certification e-mail service providing device 5000. ) may be included.

The sender terminal 1000 and the receiver terminal 2000 may be provided as various types of terminals providing an email service.

According to the embodiment, the sender terminal 1000 and the receiver terminal 2000 include a desktop computer, a server, a mobile phone, a portable multimedia player (PMP), a mobile internet device (MID), and a smart It may be provided in the form of any one of a smart phone, a desktop, a tablet computer, a note book, a net book, and other information communication devices.

The e-mail service may be an open standard e-mail service. In other words, the @mail service may be provided to the sender terminal 1000 and the receiver terminal 2000 .

According to an embodiment, the sender terminal 1000 may transmit the mail written by the sender to the email transmission server 3000 to be described later.

More specifically, the sender terminal 1000 may transmit @mail, which is generally provided in the related art. For example, the sender terminal 1000 may transmit @mail to the email transmission server 3000 through a Simple Mail Transfer Protocol (SMTP) protocol.

In addition, the sender terminal 1000 may transmit @mail that provides additional proof by utilizing a content proof block chain. For example, the sender terminal 1000 controls the SMTP, POP3, and IMAP protocols to generate and process block-chain transactions by the contents-certified e-mail service providing device 5000 to be described later, and sends @mail to an e-mail sending server (3000). ) can be sent.

According to another embodiment, the receiver terminal 2000 may finally receive @ mail written by the sender from the email reception server 4000 to be described later.

Hereinafter, the conventional @mail transmission/reception method will be omitted, and only the @mail transmission method, which provides additional proof by utilizing the proof-of-contents blockchain including the main technical features of the present invention, will be described. . Also, for clarification, @ mail will be referred to as e-mail.

The e-mail sending server 3000 and the e-mail receiving server 4000 may be linked through an Internet network. Accordingly, the e-mail sending server 3000 may transmit @ mail created by the sender to the e-mail receiving server 4000 through the Internet network.

The content-certified e-mail service providing device 5000 may provide a content-certified e-mail service using blockchain technology.

According to the embodiment, the content-certification e-mail service providing device 5000 may perform functions such as e-mail content verification, e-mail sender/receiver authentication, and e-mail send/receiver prevention proof by using block chain technology.

The content-certification e-mail service providing device 5000 will be described in more detail with reference to FIGS. 2 to 4 below.

2 is a block diagram for explaining hardware configurations of a blockchain-based content-certification e-mail service providing apparatus according to an embodiment of the present invention.

Referring to FIG. 2 , an apparatus 5000 for providing a content-certified e-mail service may include a memory 100 storing at least one command and a processor 200 executing at least one command of the memory 100. .

In addition, the content-certification e-mail service providing device 5000 is connected to a network executed through the processor 200 to perform communication, the transmission/reception device 300, the input interface device 400, the output interface device 500, and storage It may further include device 600 and the like.

Each component included in the content-certification e-mail service providing apparatus 5000 is connected by a bus 700 to communicate with each other.

The memory 100 and the storage device 600 in the content-certification e-mail service providing device 5000 may each be configured with at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory 100 may include at least one of a read only memory (ROM) and a random access memory (RAM).

The memory 100 may include at least one instruction to be executed by the processor 200 to be described later.

According to an embodiment, the at least one command causes an irreplaceable proof-of-contents token to be issued on a proof-of-contents blockchain containing e-mail content encrypted by the symmetric key of the sender's terminal, and the disclosure of the symmetric key to the receiver's terminal. A command to encrypt with a key and record in the attribute information of the content-proof token on the content-proof block chain, the contents transmitted by the user terminal when the email transmission server receives the content-proof token from the sender terminal by protocol A command for receiving the verification result of verifying the transmission history of the proof token from the e-mail transmission server and adding it to the attribute information of the content-certification token issued on the proof-of-content blockchain, the e-mail receiving server, by protocol When a content verification token is received from the sending server, the verification result of verifying the transmission history of the content verification token sent by the email sending server is received from the email receiving server, and the content verification token issued on the proof of contents blockchain When a command to record in attribute information of a token and a recipient terminal receive a content proof token from the email receiving server by protocol, the email content encrypted with the symmetric key in the content proof token sent by the email receiving server It may include a command for decrypting with a private key so that the receiver can view it.

The processor 200 may mean a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which methods according to embodiments of the present invention are performed.

As described above, the processor 200 may execute at least one program command stored in the memory 100 . According to an embodiment, the processor 200 may execute at least one software configuration described above according to at least one instruction stored in the memory 100 .

At least one software component in the block chain-based content-certification e-mail service providing device 5000 according to an embodiment of the present invention will be described in more detail with reference to FIG. 3 below.

The operation of the processor 200 performing the at least one command will be described in more detail when a method for providing a blockchain-based content-certified e-mail service according to an embodiment of the present invention will be described later.

3 is a block diagram of an apparatus for providing a content-certified e-mail service based on a block chain according to an embodiment of the present invention.

Referring to FIG. 3 , when the components 1000, 2000, 3000, and 4000 each transmit a transaction to the content-certification blockchain, the apparatus 5000 for providing a content-certification e-mail service may relay the transaction. According to the embodiment, the device 5000 for providing a content-certification e-mail service may be provided as a content-certification software development kit (SDK).

On the other hand, proof-of-content blockchain can provide a blockchain technology environment. At this time, the proof-of-content blockchain may be provided in the form of a permissioned blockchain to limit participants in the proof-of-content blockchain.

The proof-of-content blockchain may include transactions generated by the email service providing device 5000 . A method of generating a transaction will be described in more detail when the software operation of the processor 200 is described below.

4 is a block diagram illustrating software configurations of an apparatus for providing a blockchain-based content-certification e-mail service according to an embodiment of the present invention.

Referring to FIG. 4, the processor 200 in the content-certification e-mail service providing apparatus 5000 includes a token issuing unit 5100, a token transmission unit 5200, a token modification unit 5300, an attribute inquiry unit 5400, a history The inquiry unit 5500 and the event management unit 5600 may be executed.

The token issuing unit 5100 may generate a transaction for issuing a contents proof token associated with email contents on a contents proof blockchain.

In more detail according to the embodiment, the sender terminal 1000 may generate a transaction through the token issuing unit 5100 to issue a proof-of-content token with a specific data structure on the proof-of-content blockchain. At this time, the owner of the token may be the subject that issued the token. In other words, the owner of the content proof token may be the sender terminal 1000 .

The data structure of the proof-of-contents token will be described in more detail with reference to FIG. 5 below.

5 is an image for explaining a data structure of a content proof token of a blockchain-based content proof email service providing device according to an embodiment of the present invention.

Referring to FIG. 5 , as described above, the data of the proof-of-contents token may be data expressing the contents of the e-mail in the form of a non-replaceable token.

According to an embodiment, attribute information of a content proof token may be classified into standard attributes and extended attributes.

Standard attributes may include at least one of identifier (id), token type (type), owner, operator, and approver information. For example, the token type may be Content Certifiable.

In addition, extended attributes include sender and receiver email address information as on-chain extended attributes (xattr), hash of email contents to ensure confidentiality of email contents that the sender wants to send, and is used when encrypting the email contents. an encryption symmetric key obtained by encrypting a symmetric key with the recipient's public key, an e-mail sending server certificate and an e-mail receiving server certificate in which information that at least one e-mail sending server and e-mail receiving servers received the e-mail content and verified the content proof token was recorded. information may be included.

Referring back to FIG. 4 , the token transmission unit 5200 may generate a transaction for transmitting a content proof token existing on a content proof blockchain.

In more detail according to the embodiment, the token transmission unit 5200 may generate a transaction on the proof-of-contents blockchain at the request of the owner of the proof-of-contents token. Accordingly, the proof-of-content blockchain can transfer ownership of the proof-of-content token to another participant.

In other words, when the token transmission unit 5200 is called by the owner of the content proof token, it can cause the proof of content blockchain to change the owner of the proof of content token.

The token modifying unit 5300 may generate a transaction for modifying an attribute value of a content proof token existing on a content proof blockchain.

According to an embodiment, the token modifying unit 5300 generates a transaction for recording lower attribute values of extended attributes of the content proof token.

Call authority of the token modifying unit 5300 may be limited to the owner.

According to the embodiment, the token modification unit 5300 is called by the email transmission server 3000 to create a transaction to record information that the sender terminal 1000 has sent an email in the properties of the token so as to later prove it. can

In addition, the token modification unit 5300 is called by the e-mail receiving server 4000 and transmits information that the e-mail receiving server 4000 has received the e-mail transmitted from the sender terminal 1000 through the e-mail sending server 3000. You can create a transaction that records in the properties of the proof-of-contents token so that it can be verified later.

The property inquiry unit 5400 may generate a transaction to inquire the properties of the content proof token issued on the proof of contents blockchain.

According to the embodiment, when the email transmission server 3000, the email reception server 4000, and the recipient terminals 2000 receive an email, the attribute inquiry unit 5400 converts the proof-of-contents token to a proof-of-contents blockchain to view it. can be called

The history inquiry unit 5500 may generate a transaction to search the history of the proof-of-contents token issued on the proof-of-content blockchain.

According to the embodiment, the history inquiry unit 5500, while the sender terminal 1000 transmits the content verification token to the receiver terminal 2000 via the email sending server 3000 and the email receiving server 4000, the corresponding token It may be called from any one of the email sending server 3000 and the email receiving server 4000 in order to check whether this point has been reached.

For example, the history inquiry unit 5500 may sequentially search modification histories of content certification tokens based on signature information recorded in the content proof tokens by the email transmission server 3000 and the email reception server 4000 .

The event management unit 5600 may provide an event notification service that informs corresponding components of event results generated from the proof-of-contents blockchain by the operation of the components 5100, 5200, and 5300.

In other words, the event management unit 5600 determines when a transaction issued from any one of the token issuing unit 5100, the token transmission unit 5200, and the token modification unit 5300 is finally committed to the proof-of-contents blockchain. , the result event can be delivered to the subject who called the operation of the corresponding configuration.

According to an embodiment, when a content-certification token is issued on a content-certification blockchain by the token issuing unit 5100, the event management unit 5600 transmits the content to the sender terminal 1000 that has called the token issuing unit 5100. Successful issuance event information of proof token may be transmitted.

According to another embodiment, when the ownership of the proof-of-contents token is transferred on the proof-of-contents blockchain by the token transfer unit 5200, the event management unit 5600 calls the token transfer unit 5200, and the email sending server 3000 ) or the successful ownership change event information of the content proof token may be transmitted to the email receiving server 4000 .

According to another embodiment, when a sub-attribute value of an extended property of a proof-of-contents token on a proof-of-contents blockchain is modified by the token modifier 5300, the event manager 5600 calls the token modifier 5300. Successful modification event information of the proof-of-contents token may be transmitted to one email sending server 3000 or email receiving server 4000 .

In the above, the contents-certified email service system including the blockchain-based content-certified email service providing apparatus according to an embodiment of the present invention will be described. Hereinafter, a blockchain-based content-certification email service providing method implemented by the processor of the content-certified email service providing device will be described.

6 is a flowchart illustrating a method for providing a content-certified e-mail service using a blockchain-based content-certified e-mail service providing apparatus according to an embodiment of the present invention.

Referring to FIG. 6 , the processor 200 of the apparatus 5000 for providing a content-certification e-mail service includes a sender terminal 1000, an e-mail sending server 3000, an e-mail receiving server 4000, and a receiver terminal 2000 in a content-certifying block. It can be registered on the chain (S1000).

Thereafter, the processor 200 may issue a public key and a private key to the elements 1000 to 4000 permitted to access the proof-of-contents blockchain, and store the public keys of the elements 1000 to 4000 ( S2000). Accordingly, only the permitted components 1000 to 4000 may be accessible to the proof-of-content blockchain. Here, the public key and the private key may be a public key infrastructure (PKI).

The sender terminal 1000 may generate a symmetric key to encrypt the contents of the email when sending a content-certified email. Thereafter, the sender terminal 1000 may request the public key of the receiver terminal 2000, which is the final recipient of the email, from the processor 200. In other words, the processor 200 may transmit the public key of the receiver terminal 2000 to the sender terminal 1000 at the request of the sender terminal 1000 (S3000). Accordingly, the sender terminal 1000 can encrypt the contents of the email using the symmetric key.

In the blockchain-based method for providing proof-of-contents email according to an embodiment of the present invention, all components (1000 to 4000) registered in the proof-of-contents blockchain can access to verify the property information of the proof-of-contents token, but Since only the recipient terminal 2000 can access the symmetric key for decryption, it is possible to provide an integrity and high-reliability blockchain-based content-certified e-mail providing method.

Thereafter, the processor 200 executes the token issuing unit 5100 by a call of the sender terminal 1000 to generate an irreplaceable content proof token based on the encrypted e-mail content transmitted from the sender terminal 1000 on the content proof block chain. can be issued on the platform (S4000).

Here, the content proof token may include the sender's e-mail address and the recipient's e-mail address, the hash value of the e-mail content encrypted with the symmetric key, and the symmetric key information encrypted with the public key of the receiver's terminal 1000 as sub-attributes of the extended attribute. there is.

The processor 200 may execute the event management unit 5600 to inform the sender terminal 1000 that the content certification token has been successfully issued.

According to the embodiment, the processor 200 may execute the token issuing unit 5100 to initialize content proof token issuance and attribute information of the sender terminal 1000 .

For example, the processor 200 executes the token issuing unit 5100 to cause the proof-of-contents block chain to among the attributes of the token ID, owner information, sender/receiver email address, email content hash value, and email content encryption symmetric key. At least one value can be initialized. At this time, the owner of the token may be the sender terminal 1000.

In addition, the processor 200 may encrypt the symmetric key used to encrypt the email with the public key of the recipient's terminal 1000 and record it in the properties of the proof-of-contents token (S5000). Accordingly, other users other than the recipient or the e-mail sending server 3000 and the e-mail receiving server 4000 cannot check the corresponding e-mail content, so confidentiality of the encrypted e-mail content can be guaranteed.

When the ownership of the content proof token is changed from the sender terminal 1000 to the email sending server 2000 on the proof of content blockchain, the processor 200 executes the event management unit 5560 to provide ownership change event information of the proof of content token. may be transmitted to the sender terminal 1000.

Thereafter, the sender terminal 1000 may transmit attribute information of the proof-of-contents token to the email transmission server 2000 using a Simple Mail Transfer Protocol (SMTP) email protocol (S6000).

Thereafter, the processor 200 executes the attribute inquiry unit 5400 when the e-mail transmission server 3000 requests verification of the fact that the sender terminal 1000 has sent the e-mail, so that the e-mail transmission server 3000 establishes a proof-of-contents block chain. It is possible to query the contents proof token of the above.

In other words, the processor 200 may enable verification of the transmission history of the content-certification token at the request of the email transmission server 3000 (S7000).

According to the embodiment, the processor 200 executes the history inquiry unit 5500 so that the e-mail transmission server 3000 records the e-mail address of the sender recorded in the content-certification token and the sender terminal that sent the content-certification token. The sender terminal 1000 can verify whether the e-mail address of the e-mail address matches the user who sent the content-certified e-mail.

When the e-mail address of the sender in the content-certification token and the e-mail address of the sender terminal that sent the content-certification token match, that is, when the sender terminal 1000 is the user who sent the content-certification e-mail, the processor 200 ) executes the token modification unit 5300 according to the request of the e-mail transmission server 3000, and converts the ID of the content verification token, the sender e-mail address, the recipient e-mail address, and the hash value of the e-mail content into the private key of the e-mail transmission server 3000. After signing, it can be stored as a proof value in a sub-property of the extended property of the proof-of-contents token. Thereafter, the processor 200 may transmit a modification completion signal to the email transmission server 3000 .

Thereafter, the processor 200 executes the token modification unit 5300 by the call of the email sending server 3000, so that the proof of content block chain transfers ownership of the content proof token from the email sending server 3000 to the email receiving server ( 4000) can be changed. Accordingly, the email sending server 3000 may transmit the ID attribute of the content proof token to the email receiving server 4000 based on the email protocol.

When the email is successfully received from the email sending server 3000, the email receiving server 4000 may request the processor 200 to verify the content proof token (S8000).

Accordingly, the e-mail receiving server 4000 transmits the e-mail address of the sender terminal 1000 in the content-certification token and the content-certification token, as in the content-certification token verification method by the e-mail transmission server 3000 described above. It is possible to compare whether the email address of the sender terminal 1000 matches.

When the e-mail address of the sender terminal 1000 in the content-proof token matches the e-mail address of the sender terminal 1000 that sent the content-proof token, the processor 200 determines the public key of the e-mail transmission server 3000. It is possible to decrypt the proof value of the e-mail sending server 3000 recorded in the content certification token by using . Accordingly, the email sending server 3000 can verify the email sending history.

Subsequently, when the transmission history of the content certification token to the sender terminal 1000 and the email sending server 2000 is verified, the processor 200 converts the proof of content to the attribute of the token according to the request of the email receiving server 3000. Transactions that require modification can be created on the proof-of-contents blockchain.

Therefore, the proof-of-contents blockchain uses the ID of the proof-of-contents token signed with the private key of the email receiving server 3000, the sender's email address, the recipient's email address, the email content hash value, and the proof value of the email sending server as extended attributes of the content proof token. I can save it as a proof value in my sub-property. Thereafter, the processor 200 may transmit a modification completion signal to the email reception server 4000 .

When the e-mail receiving server 3000 transmits a content proof token to the recipient terminal 4000, the ownership of the content proof token may be changed from the e-mail receiving server 3000 to the recipient terminal 4000 in the content proof block chain.

Thereafter, the processor 200 may execute the event management unit 5600 to transmit a signal of completion of ownership modification of the content certification token to the email reception server 3000 .

Thereafter, when the recipient terminal 4000 successfully receives the content verification token, the processor 200 may decrypt the encrypted e-mail contents using the private key of the recipient terminal 4000 (S9000).

In more detail according to the embodiment, the processor 200 decrypts the encryption symmetric key information of the proof-of-contents token attribute in the processor 200 using the secret key of the receiver terminal 4000 to encrypt the actual e-mail content. A symmetric key can be obtained.

Thereafter, the processor 200 may decrypt the hash value of the e-mail content using the symmetric key and provide the decrypted hash value to the recipient terminal 4000 . Accordingly, the recipient can check the decrypted e-mail contents through the recipient terminal 4000 .

In the above, an apparatus and method for providing a proof-of-contents e-mail service based on a block chain according to an embodiment of the present invention have been described.

An apparatus and method for providing a blockchain-based content-certification e-mail service according to an embodiment of the present invention includes the steps of issuing an irreplaceable content-certification token containing e-mail content encrypted by a symmetric key of a sender terminal on a content-certification blockchain , Encrypting the symmetric key with the public key of the recipient terminal so that it is recorded in the attribute information of the content-certification token on the content-certification blockchain, when the email sending server receives the content-certification token from the sender terminal by protocol , receiving a verification result of verifying the transmission history of the content proof token transmitted by the user terminal from the email transmission server, and adding it to attribute information of the content proof token issued on the proof of content blockchain, e-mail When the receiving server receives the content verification token from the e-mail transmission server through the protocol, the verification result of verifying the transmission history of the content verification token transmitted by the e-mail transmission server is received from the e-mail reception server, recording in the attribute information of the content proof token issued on the blockchain, and when the recipient terminal receives the content proof token from the email receiving server by protocol, the content transmitted by the email receiving server By including the step of decrypting the e-mail content encrypted with the symmetric key in the proof token with the private key so that the recipient can view it, the sender terminal can easily track the process of sending and receiving the e-mail through the content proof token, and it is compatible with the e-mail protocol. and provide a high-efficiency, high-accuracy, high-reliability and low-cost blockchain-based content-certification e-mail service provision device and method capable of verifying user authentication, e-mail content integrity, and non-repudiation of sending and receiving activities by applying block-chain technology. can

In addition, an apparatus and method for providing a blockchain-based content-certified e-mail service according to an embodiment of the present invention verifies the integrity of encrypted e-mail content through a content-certified blockchain, so that a sender terminal and a receiver terminal can be connected without a third-party trust authority. Confidentiality can be maintained, so it can be applied even in environments requiring high confidentiality such as military or financial use.

The operation of the method according to the embodiment of the present invention can be implemented as a computer readable program or code on a computer readable recording medium. A computer-readable recording medium includes all types of recording devices in which data that can be read by a computer system is stored. In addition, computer-readable recording media may be distributed to computer systems connected through a network to store and execute computer-readable programs or codes in a distributed manner.

In addition, the computer-readable recording medium may include hardware devices specially configured to store and execute program instructions, such as ROM, RAM, and flash memory. The program command may include high-level language codes that can be executed by a computer using an interpreter or the like as well as machine code generated by a compiler.

Although some aspects of the present invention have been described in the context of an apparatus, it may also represent a description according to a corresponding method, where a block or apparatus corresponds to a method step or feature of a method step. Similarly, aspects described in the context of a method may also be represented by a corresponding block or item or a corresponding feature of a device. Some or all of the method steps may be performed by (or using) a hardware device such as, for example, a microprocessor, programmable computer, or electronic circuitry. In some embodiments, one or more of the most important method steps may be performed by such an apparatus.

In embodiments, a programmable logic device (eg, a field programmable gate array) may be used to perform some or all of the functions of the methods described herein. In embodiments, a field programmable gate array may operate in conjunction with a microprocessor to perform one of the methods described herein. Generally, methods are preferably performed by some hardware device.

Although the above has been described with reference to preferred embodiments of the present invention, those skilled in the art can variously modify and change the present invention without departing from the spirit and scope of the present invention described in the claims below. You will understand that you can.

1000: sender terminal 2000: receiver terminal
3000: Email sending server 4000: Email receiving server
5000: content-certified e-mail service providing device
5100: Token issuing unit 5200: Token transmission unit
5300: Token modification unit 5400: Attribute inquiry unit
5500: history inquiry unit 5600: event management unit

Claims (20)

A device for providing a content-certified e-mail service based on a content-certified blockchain,
memory; and
A processor executing at least one instruction stored in the memory,
The at least one command,
In response to a call from a sender terminal that encrypts email content with a symmetric key and transmits the encrypted email to a receiver terminal, a transaction is generated that issues an irreplaceable proof-of-contents token containing predetermined attribute information, and the proof-of-contents blockchain a command for issuing the content-certification token to the sender terminal;
After the email sending server receives the content proof token from the sender terminal, it generates a transaction that changes the attribute information of the content proof token, so that the proof value of the email sending server on the content proof blockchain is the content proof token. command to be added to the attribute information of;
After the e-mail receiving server receives the content-proof token from the e-mail sending server, it creates a transaction that changes the attribute information of the content-proof token, so that the proof value of the e-mail receiving server on the content-proof blockchain is the content-proof token. command to be added to the attribute information of; and
After the recipient terminal receives the content proof token from the e-mail receiving server, in response to a call from the recipient terminal, an encrypted symmetric key included in attribute information of the content proof token is provided to the recipient terminal, so that the recipient terminal A device for providing a blockchain-based content-certified e-mail service, including a command for the terminal to decrypt the encrypted symmetric key with its own private key to obtain the symmetric key, and to decrypt and view the encrypted e-mail with the symmetric key. According to claim 1,
After the email sending server receives the content proof token from the sender terminal, it generates a transaction that changes the attribute information of the content proof token, so that the proof value of the email sending server on the proof of content blockchain is the content proof token. The command to add to the token's attribute information is
and a command for changing the owner of the content proof token to the email transmission server. According to claim 2,
After the e-mail receiving server receives the content-proof token from the e-mail sending server, it creates a transaction that changes the attribute information of the content-proof token, so that the proof value of the e-mail receiving server on the proof-of-content blockchain is The command to add to the token's attribute information is
and a command for changing the owner of the content proof token to the email reception server. According to claim 1,
The sender terminal, the e-mail transmission server, the e-mail reception server, and the receiver terminal are pre-registered in a content-certification blockchain. According to claim 1,
Further comprising a storage device for storing public keys of the sender terminal, the email transmission server, the email reception server, and the receiver terminal, the block chain-based content-certification email service providing apparatus. [6] The apparatus of claim 5, wherein the public keys are generated from a public key infrastructure (PKI). According to claim 1,
The command to create a transaction that changes attribute information of the content proof token so that the proof value of the e-mail sending server is added to the attribute information of the content proof token on the content proof blockchain,
a command for accepting, from the e-mail sending server, information about whether the e-mail address of the sender in the content-certification token matches the e-mail address of the sender terminal that sent the content-certification token; and
If the e-mail addresses match, at least a part of the attribute information of the content-certification token is signed with the private key of the e-mail transmission server to generate a proof value of the e-mail transmission server. E-mail service provider. 8. The method of claim 7, wherein the proof value of the email sending server includes values obtained by encrypting an ID of a content verification token, a sender's email address, a recipient's email address, and a hash value of email content with a private key of the email sending server. Content proof e-mail service providing device. According to claim 1,
The command for generating a transaction for changing the attribute information of the content proof token so that the proof value of the e-mail receiving server is added to the attribute information of the content proof token on the content proof blockchain,
a command for accepting, from the e-mail receiving server, information about whether the e-mail address of the sender in the content-certification token matches the e-mail address of the sender terminal; and
If the e-mail addresses match, at least part of the attribute information of the content-certification token is signed with the private key of the e-mail receiving server to generate a proof value of the e-mail receiving server. E-mail service delivery device. According to claim 1,
The e-mail is provided as an open standard e-mail (@mail), a blockchain-based content-certified e-mail service providing device. Token issuer for issuing irreplaceable proof-of-content tokens, token modifier for changing properties of issued proof-of-contents tokens, and attribute inquiry unit for providing token property information, providing content-certification e-mail service that operates based on program commands A method for a device to provide a content-certified e-mail service based on a content-certified blockchain,
The token issuing unit generates a transaction for issuing an irreplaceable proof-of-contents token including predetermined attribute information in response to a call from a sender terminal that encrypts email contents with a symmetric key and transmits the encrypted email to a receiver terminal, issuing the content-certification token to the sender terminal on the content-certification block chain;
The token modifying unit, after the email sending server receives the content proof token from the sender terminal, generates a transaction for changing the attribute information of the content proof token, and the proof value of the email sending server on the content proof block chain. adding to attribute information of the content proof token;
After the email receiving server receives the content proof token from the email sending server, the token modifying unit generates a transaction for changing attribute information of the content proof token, and the proof value of the email receiving server on the proof of content blockchain. adding to attribute information of the content proof token; and
The attribute inquiry unit, after the recipient terminal receives the content proof token from the email receiving server, sends the encrypted symmetric key included in the attribute information of the content proof token to the recipient terminal in response to a call from the recipient terminal. Provided, that the recipient terminal decrypts the encrypted symmetric key with its own private key to obtain the symmetric key, and decrypts the encrypted e-mail with the symmetric key to view it. How We Provide Email Services. 12. The method of claim 11, wherein the device for providing the content-certified e-mail service includes a token transmission unit,
The token modifying unit, after the email sending server receives the content proof token from the sender terminal, generates a transaction for changing the attribute information of the content proof token, thereby verifying the email sending server on the content proof block chain. A step of causing a value to be added to the attribute information of the proof-of-contents token
and changing, by the token transmission unit, an owner of the content proof token to the email sending server. According to claim 12,
After the email receiving server receives the content proof token from the email sending server, the token modifying unit generates a transaction for changing attribute information of the content proof token, and the proof value of the email receiving server on the proof of content blockchain. The step of adding this to the attribute information of the proof-of-contents token
and changing, by the token transmission unit, an owner of the content proof token to the email receiving server. According to claim 11,
Wherein the sender terminal, the e-mail transmission server, the e-mail reception server, and the recipient terminal are pre-registered in a content-certification blockchain, a blockchain-based content-certification email service providing method. [Claim 12] The method of claim 11, wherein the content-certification e-mail service providing apparatus stores public keys of the sender terminal, the e-mail sending server, the e-mail receiving server, and the recipient terminal. [Claim 16] The method of claim 15, wherein the public keys are generated from a public key infrastructure (PKI). According to claim 11,
The step of generating, by the token modifying unit, a transaction for changing the attribute information of the content proof token so that the proof value of the e-mail sending server is added to the attribute information of the content proof token on the content proof blockchain,
receiving, from the e-mail sending server, information about whether the e-mail address of the sender in the content-certification token matches the e-mail address of the sender terminal that sent the content-certification token; and
If the e-mail addresses match, generating a proof value of the e-mail transmission server by signing at least a part of the attribute information of the content verification token with the private key of the e-mail transmission server, the blockchain-based content verification e-mail How We Provide Our Services. 18. The method of claim 17, wherein the proof value of the e-mail sending server includes values obtained by encrypting an ID of a content verification token, a sender's e-mail address, a recipient's e-mail address, and a hash value of e-mail content with a private key of the e-mail sending server. How to provide proof-of-contents e-mail service. According to claim 11,
The step of generating, by the token modifying unit, a transaction for changing attribute information of the content proof token so that the proof value of the e-mail receiving server is added to the attribute information of the content proof token on the content proof blockchain,
receiving information about whether the email address of the sender in the content verification token matches the email address of the sender's terminal from the email receiving server; and
If the e-mail addresses match, generating a proof value of the e-mail receiving server by signing at least some of the attribute information of the content-certification token with the private key of the e-mail receiving server, How We Provide Our Services. According to claim 11,
The e-mail is provided as an open standard e-mail (@mail), a method for providing a blockchain-based content-certified e-mail service.

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