CN110351258A - A kind of distributed electronic mailbox system based on no coin block chain technology - Google Patents

Abstract

The invention relates to block chain technology and electronic mailbox technology, and proposes a distributed electronic mailbox system based on currencyless block chain technology. The system includes: a client, a non-system node server and a system node server. The present invention establishes the mapping relationship between users and blockchain addresses. By encrypting and packing the subject and content of the user's letter into the block and sending it to the recipient address in the blockchain network, the non-system node server of the alliance chain acts as the Postmen, advertisers put the cost of advertising as postage, and recipients decrypt and view the mail through their private key to achieve the purpose of communication. The present invention utilizes the characteristics of the distributed ledger of the blockchain, and attaches the operation of the system to the alliance chain, avoiding the risks of mail loss, inaccessibility, deletion, and tampering, and realizes a privacy-protecting, low-cost, and secure solution. Reliable distributed e-mail system.

Description

A distributed electronic mailbox system based on currencyless blockchain technology

technical field

The present invention relates to block chain technology and electronic mailbox technology, and in particular to a distributed electronic mailbox system based on coinless block chain technology.

Background technique

With the development of network communication technology, e-mail system has become a common tool for people to communicate. However, in the actual use of the current centralized e-mail, there are the following risks:

risk of loss

The centralized mailbox service platform, due to its limited operating costs, has limited backup of users’ email data. In the event of a disaster, data loss will occur, or the service provider’s operating services will be shut down, emails cannot be accessed, or even services will be permanently shut down, causing users Losses of mail that can never be recovered.

Risk of inaccessibility

The centralized mailbox service platform, due to its high degree of centralization, may cause the server running speed to drop or even become paralyzed in a short period of time, and user access delays or denial of access may occur once users access and log in centrally.

risk of being attacked

In the centralized email service system, some email protocols did not fully consider the issue of email security at the beginning of the design, and different service providers pay different attention to the security of the email system. Hackers attack the vulnerabilities of the mailbox system and brute force the simple encrypted email data, which will cause the user's email content to be leaked, stolen or tampered with.

Risk of burglary

Due to the centralized operation mode of the existing mailbox service system, in the event of improper use of personnel, organizations or individuals with relevant interests will guard against theft, infringing on users' privacy, and even stealing users' personal information.

monitor risk

The email data sent by the user needs to be transmitted between different servers. Once the transmission between the servers is not encrypted, it is easy to cause the email information to be intercepted and the risk of being monitored by these servers.

The above risks have greatly troubled enterprises, governments and individual users, and blockchain technology is expected to eliminate the above risks. Blockchain is a decentralized chain data structure that uses distributed node consensus algorithm to generate, verify and update transaction data, and uses asymmetric cryptography to ensure the security of data transmission and access, and generates unreliable data. A tampered and unforgeable distributed ledger to establish a mutual trust data network. In the public blockchain, every node is equal, and there is no centralized management agency. This "decentralization" feature makes the blockchain independent of a third-party central agency, and its operation can be independently verified. , the damage or loss of any small part of the nodes in the network will not affect the operation of the entire system. However, in general, the public chain and the virtual currency with strong financial attributes such as Token are combined. If an incentive mechanism can be found to replace the virtual currency, then "de-tokenization" can be achieved, and the introduction of modern society into the alliance chain Commercials can do just that. Based on the above analysis, the present invention can realize a distributed electronic mailbox system with privacy protection, low cost, safety and reliability.

SUMMARY OF THE INVENTION

The invention overcomes the deficiencies of the prior art, and the technical problem to be solved is: to provide a distributed electronic mailbox system based on the coinless block chain technology, and to solve the privacy leakage and information security problems of the central server electronic mailbox system.

A distributed electronic mailbox system based on a coinless blockchain technology, including a client, a non-system node server, and a system node server; the three are connected through a blockchain network communication;

Among them, the client includes a client core module and a client platform interface; the client core module includes a user registration module, a user login module, an address book management module, a letter writing and email sending module, a sent module, an inbox module, an account Management module, advertisement module and exit module; the user registration module is used for the creation of user information; the user login module is used for user information verification; the address book management module is used for the addition, deletion, modification and checking of contact names, public keys, and email addresses; writing The letter and send mail module is used for text editing, letter encryption, mail sending and broadcasting; the sent module is used for users to view and retrieve sent mail; the inbox module is used for received letter decryption and mail retrieval; The account management module is used for user information modification and key management; the advertisement module is used for the push and update of advertisements; the exit module is used to realize the function of the user exiting the client;

The client platform interface includes the user registration login window, the address book management window, the writing and sending email windows, the sent window, the inbox window, and the personal account management window. Login password, generate or import the user's private key, public key, email address/on-chain address; after a registered user successfully logs in to the client, create a personal address book through the address book management window, and add the names, public keys, and email addresses of other users /Add the address on the chain to the mail address list; edit the subject and content of the letter through the writing and sending mail windows, add the recipient address, and encrypt the content of the letter and send it to the recipient address in the blockchain network; View and retrieve emails after sending in the sending window; decrypt, view and retrieve emails from other addresses through the inbox window; modify user names and passwords, and manage keys through the account management window;

The non-system node server includes several endorsement nodes, sorting nodes and confirmation nodes; the email sending request sent by the client is checked for legality, and after endorsement, sorting, and confirmation, it is written into the block ledger;

The system node server includes a CA node, and the CA node is used to provide the identity information of the network node and implement authority management.

Among them, the blockchain is a distributed structure of the P2P network, a consortium chain with membership and authority management functions, and does not involve any coins and certificates.

Among them, the mailbox system is a decentralized system, and the damage or loss of any small part of the nodes in the network does not affect the operation of the system.

Among them, the mail information data in the mailbox system is all uploaded to the chain.

Among them, in the mailbox system, the subject and content of the letter are encrypted and recorded on the blockchain, and asymmetric cryptography is used to ensure the security of mail information data transmission and access.

Among them, the operation of the mailbox system is attached to the blockchain, and mail is delivered by the non-system node server of the alliance chain. The cost of advertising advertisements by advertisers is used as the postal cost. When users use the client with advertisements, they can send mail for free.

Among them, users in the mailbox system can extract and decrypt the mail information sent to their own addresses, so as to achieve the purpose of checking letters.

Among them, any sensitive information of users in the mailbox system is stored in the client.

The client includes a desktop application or a mobile phone, and the client is responsible for sending email messages and retrieving and receiving block data.

Among them, the client in the mailbox system stores the plaintext of all passwords and keys in the memory area. After the user exits the client, all the data in the memory area is automatically cleared, and the rest of the client data is stored in the client's local database storage area.

Compared with the prior art, the present invention has the following beneficial effects:

1. The present invention is based on blockchain technology and is decentralized. Even if a node is damaged in the network, it will not affect the operation of the entire system, and mail will never be lost.

2. The present invention is based on the blockchain technology, and all non-management nodes on the chain store mail data. As long as the network communication is smooth, there will be no user access delay or access refusal.

3. The present invention is based on blockchain technology, using hash function and asymmetric encryption algorithm, hackers cannot crack the encrypted mail data, so it will not cause the user's mail content to leak, and the chain structure of the blockchain can ensure that the Data cannot be tampered with.

4. The present invention is based on the blockchain technology, any sensitive information of the user is only stored on the user's client, even the system node server does not have the right to access the private data of these users, thus avoiding the possibility of self-stealing by organizations or individuals related to interest, User privacy is protected.

5. The present invention is based on the blockchain technology, and the mail data always exists in the form of cipher text in the transmission from the starting point to the end point, which ensures the security of the mail data in the entire transmission process.

6. The present invention is based on the blockchain technology, and the non-system node servers can be operated and maintained by a large number of scattered institutions and individuals, which not only guarantees the normal operation of the system, but also provides a large number of commercial profit opportunities.

Description of drawings

1 is a schematic diagram of a distributed electronic mailbox system based on a coinless blockchain technology provided by an embodiment of the present invention;

2 is an architectural diagram of a distributed electronic mailbox system based on a coinless blockchain technology provided by an embodiment of the present invention;

3 is a client data storage structure diagram of a distributed electronic mailbox system based on a coinless blockchain technology provided by an embodiment of the present invention;

4 is a flow chart of a registration module of a distributed electronic mailbox system based on a coinless blockchain technology provided by an embodiment of the present invention;

5 is a schematic diagram of a private key encryption principle of a distributed electronic mailbox system based on a coinless blockchain technology provided by an embodiment of the present invention;

6 is a flowchart of a login module of a distributed electronic mailbox system based on a coinless blockchain technology provided by an embodiment of the present invention;

7 is a schematic diagram of login verification of a distributed electronic mailbox system based on a coinless blockchain technology provided by an embodiment of the present invention;

8 is a functional diagram of an address book management module of a distributed electronic mailbox system based on a coinless blockchain technology provided by an embodiment of the present invention;

9 is a functional diagram of an account management module of a distributed electronic mailbox system based on a coinless blockchain technology provided by an embodiment of the present invention;

10 is a flow chart of a letter writing and email sending module of a distributed e-mail box system based on a coinless blockchain technology provided by an embodiment of the present invention;

11 is a schematic diagram of a sending email module of a distributed electronic mailbox system based on a coinless blockchain technology provided by an embodiment of the present invention;

12 is a schematic diagram of a sent module of a distributed electronic mailbox system based on a coinless blockchain technology provided by an embodiment of the present invention;

13 is a schematic diagram of an inbox module of a distributed electronic mailbox system based on a coinless blockchain technology provided by an embodiment of the present invention;

14 is a flowchart of an endorsement node of a distributed e-mail box system based on a coinless blockchain technology provided by an embodiment of the present invention;

15 is a flowchart of a sorting node of a distributed electronic mailbox system based on a coinless blockchain technology provided by an embodiment of the present invention;

FIG. 16 is a flowchart of a confirmation node of a distributed electronic mailbox system based on a currencyless blockchain technology provided by an embodiment of the present invention.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not All the embodiments; based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work, all belong to the protection scope of the present invention.

Since there are many types of blockchain technologies, in order to facilitate understanding of the implementation method of the present invention, some important details are described.

In the blockchain network, data is permanently recorded in the form of files, called blocks. Once a new block is confirmed on the chain, it cannot be changed or deleted. Each block records all the transaction events that occurred in the period before it was created, and these transactions use asymmetric encryption algorithm. Example: When user A wants to send a message to B, A encrypts the message with B's public key, and then signs it with A's private key; after B receives the message, it uses A's public key to verify that it is indeed sent by A , and decrypt the message sent by A with B's private key. Blockchains are divided into public chains, alliance chains, and private chains. Only the alliance chain can be currencyless, have the ability to manage membership and authority, and have a sufficient degree of decentralization. For example, the consortium chain Fabric includes CA nodes, endorsement nodes, ordering nodes, and confirmation nodes. The system node server refers to the CA node, and the other three nodes belong to the non-system node server. The CA node provides the identity information of the network node and implements authority management. The endorsement node verifies, simulates execution and endorses the transaction plan. The ordering node sorts the transactions sent by each node. Confirmation nodes are responsible for verifying the legitimacy of transactions and updating and maintaining blockchain data and ledger status. Each confirming node keeps a copy of the ledger.

The core of the present invention is to establish a mapping relationship between users and blockchain addresses. The client encrypts and packs the user's letter into the block, and sends it to the recipient address in the blockchain network, and can also send the message sent to its own address. The mail is extracted and decrypted to achieve the purpose of checking the letter. The operation of this system is attached to the blockchain, and the non-system node server of the alliance chain acts as a postman, and the cost of advertising by advertisers is used as postage.

The schematic diagram of the distributed electronic mailbox system based on the currencyless blockchain technology of the present invention is shown in Figure 1. User A sends letters to user B through the client, and user B checks and receives emails on the client; all emails of all users are encrypted Stored in distributed network nodes, these nodes provide distributed encrypted storage services for the entire system, and the incentive for these nodes is the fee provided by advertisers. Browse advertisements to achieve the purpose of using the email system for free. It can be seen from FIG. 1 that the system of the present invention constructs a complete closed loop of business ecology.

The architecture diagram of the distributed electronic mailbox system based on the currencyless blockchain technology of the present invention is shown in Figure 2, including a client, a non-system node server, and a system node server; the three are communicated and connected through a blockchain network;

Among them, the client includes a client core module and a client platform interface; the client core module includes a user registration module, a user login module, an address book management module, a letter writing and email sending module, a sent module, an inbox module, an account Management module, advertisement module and exit module; the user registration module is used for the creation of user information; the user login module is used for user information verification; the address book management module is used for the addition, deletion, modification and checking of contact names, public keys, and email addresses; writing The letter and send mail module is used for text editing, letter encryption, mail sending and broadcasting; the sent module is used for users to view and retrieve sent mail; the inbox module is used for received letter decryption and mail retrieval; The account management module is used for user information modification and key management; the advertisement module is used for the push and update of advertisements; the exit module is used to realize the function of the user exiting the client;

The client platform interface includes the user registration login window, the address book management window, the writing and sending email windows, the sent window, the inbox window, and the personal account management window. Login password, generate or import the user's private key, public key, email address/on-chain address; after a registered user successfully logs in to the client, create a personal address book through the address book management window, and add the names, public keys, and email addresses of other users /Add the address on the chain to the mail address list; edit the subject and content of the letter through the writing and sending mail windows, add the recipient address, and encrypt the content of the letter and send it to the recipient address in the blockchain network; View and retrieve emails after sending in the sending window; decrypt, view and retrieve emails from other addresses through the inbox window; modify user names and passwords, and manage keys through the account management window;

The non-system node server includes several endorsement nodes, sorting nodes and confirmation nodes; the email sending request sent by the client is checked for legality, and after endorsement, sorting, and confirmation, it is written into the block ledger;

The system node server includes a CA node, and the CA node is used to provide the identity information of the network node and implement authority management.

The underlying structure is a system node server composed of several CA nodes. These management nodes provide, generate, or cancel identity information based on digital certificates for non-system node servers in the blockchain network to implement authority control management. The non-system node server in the middle layer constitutes a decentralized peer-to-peer network node, which is responsible for storing and processing mail data on the chain. It is divided into endorsement nodes, sorting nodes and confirmation nodes. The top-level client not only contains all the core modules and operations of the e-mail system, but also stores the user's personal sensitive information, especially the user's private key. The core operations of the client, such as private key generation, private key storage, private key deletion, address book management, letter writing, etc., do not need to interact with non-system node servers. Other operations such as sending emails and querying letters are ultimately To connect blockchain nodes. The client is divided into two layers of data storage structure: the memory area and the local database storage area. The memory area stores all the user's passwords and key plaintexts. After the user exits the client, all the data in the memory area is automatically cleared, and the rest of the client data is stored in the The local database storage area, as shown in Figure 3.

The execution subject of the embodiment of the present application is the client of the electronic mailbox, the non-system node server, and the system node server, and each core function module in the architecture diagram is described in detail below.

client

Registration module - the system of the present invention requires user registration to ensure the operation authority for the mailbox system and the blockchain key. The process of the user registering the module on the client is shown in Figure 4. The user first establishes a personal user name and login password, and the client automatically encrypts the login password, and then generates or imports the user's private key, public key, and email address. The email address is the address of the blockchain, which is generated by the public key, and the public key is generated by the private key. The private key can be automatically generated by the system client, or the user can import the existing private key outside the system. The system does not store the user's private key in plaintext, but automatically stores it encrypted. The principle and process of encrypting the private key by the login password are shown in Figure 5. First, the client generates a random number of several bytes, that is, the master key, then uses the login password to encrypt the master key to generate the master key ciphertext, and then uses the master key to encrypt the private key to generate the private key ciphertext. Finally, the login password, master key and private key are stored in the memory area, and the master key ciphertext, private key ciphertext, user name, user public key, and user email address are placed in the client's local database storage area.

Login module - used for user login verification, the process is shown in Figure 6. When a user initiates a login authentication request on the client side, he or she can enter the system only after correctly verifying the user name and password. Once they enter the system, they have the control authority over the system, especially the operation authority of the blockchain wallet under the user name. During login verification, the client will encrypt the password entered by the user to obtain the ciphertext of the login password, and then compare it with the ciphertext of the login password stored during the registration of the user with the same name. If they are the same, the login is successful; otherwise, the login fails. The principle is shown in Figure 7. After the user logs in successfully, the client uses the login password to decrypt the master key ciphertext, and then uses the master key to decrypt the user's private key, and stores the decrypted master key, user private key, and login password in memory.

Exit module - for the user to exit from the client, the client will automatically clear all memory area data. Switch between different users, log out first, and then log in.

Address book management module - including the addition, deletion, modification and checking of contact names, public keys, and email addresses. The functions are shown in Figure 8. After the user logs in to the client, he can add the contact's name, public key, email address/address on the chain, and the client stores it in the local database, and establishes the retrieval list and retrieval pointer of the contact, which is also stored in the local database. The user deletes/modifies the contact name, public key, and email address, that is, deletes/modifies the contact data of the client, and deletes/modifies the corresponding data in the retrieval list at the same time. The user types in the contact's name, public key or email address to query, the client traverses the search list according to the keywords, and returns the query results from the database.

Account management module - including modification of user name and login password, export, deletion, generation and import of private key, public key and email address, the functions are shown in Figure 9. After the user logs in to the client, the user name and login password can be modified, and the client automatically re-encrypts and stores the login password, and regenerates the master key, master key ciphertext and private key ciphertext. The private key, public key, and email address can also be exported and stored outside the client system. Users can also delete the private key, public key, and email address, and then regenerate and import the private key, public key, and email address. The client automatically regenerates the private key ciphertext and stores it in the local database.

Writing and sending email modules - including the creation, editing and sending of emails, the process is shown in Figure 10. The user first enters or adds the recipient address of the email in the writing and sending email windows, and the client will automatically add the user's own email address after the recipient address, that is, the client will send an email to the user by default. Then fill in the subject of the email, and then fill in the content of the email. After editing, click Send. The principle of the sending email module is shown in Figure 11. After the user clicks send, the client first packages the subject and content of the email, and then encrypts it with the recipient's public key, and sends the sender's address and recipient's address. , encrypted mail and other information packaging. In order to use the private key to sign and authorize the sent mail, it is necessary to decrypt the private key ciphertext with the master key to obtain the user's private key, and then use the user's private key to encrypt and sign the packaged sending information. Finally, the client sends the signed sending information. It is sent to the non-system node servers in the blockchain network. These node servers then broadcast the information to other nodes in the blockchain network. The newly sent information is packaged into blocks by the network nodes and then synchronized to other nodes again. Since the newly added blocks on the blockchain are verified and confirmed by the nodes of the entire network, the data will not be forked and changed again, so the final successful sending of the email has a confirmation process.

Sent module - including sent mail and mail retrieval. The principle of the sent mail function is shown in Figure 12. The client will scan the block data in the blockchain, retrieve the user's email address, and extract the address. All received mail information, extract the information that the user is the recipient in the received mail information, then use the user's public key to decrypt and verify, decrypt the private key ciphertext with the master key to obtain the private key, and reuse the mail information The user's private key is decrypted, the mail is added to the sent mail list, and the subject and content of the user's sent mail are displayed. The client will store the data of all sent mails in the local database and establish a retrieval list and retrieval pointer, which are also stored in the local database, and then update the database after waiting for new mails. The user types in text keywords for information query, the client traverses the search list according to the keywords, and returns the query results from the database.

Inbox module - including the decryption of received letters and email retrieval. The principle of receiving emails is shown in Figure 13. The client scans the block data in the blockchain, retrieves the user's email address, and extracts the For all received email messages at the address, the sender is the user's own sending message, and in order to verify that the received message is indeed sent by the sender, the received email message is decrypted using the sender's public key For verification, decrypt the private key ciphertext with the master key to obtain the private key, and then decrypt the email message with the user's private key to display the subject and content received by the user, and add it to the recipient mail list. The client will store the mail data of all these recipients in the local database and establish a retrieval list and retrieval pointer, which are also stored in the local database, and then wait for new mail to update the database. The user types in text keywords for information query, the client traverses the search list according to the keywords, and returns the query results from the database.

non-system node server

Endorsement node - In the endorsement stage, the endorsement node checks the validity of the email sending request sent by the client, then simulates the execution of the smart contract to obtain the sending request result, and finally judges whether the email sending request is supported according to the set endorsement logic. If the endorsement logic decides to support mailing requests, it will sign the request and send it back to the client. If the endorsing node determines that the request is not supported, an error message is returned to the client. Its process is shown in Figure 14.

Sorting Node - In the sorting phase, the sorting node sorts the mailing events according to the sorting service, and determines the temporal relationship between the mailing events. The sorting service sorts the mail sending events received within a period of time, then packs the sorted mail sending events into blocks, and then broadcasts the blocks to the rest of the nodes, so as to ensure that all nodes receive a set of events in the same order. mail sending event. Its flow is shown in Figure 15.

Confirmation node - In the confirmation phase, the confirmation node performs a series of checks on the sorted mail sending events, including the integrity check of the mail sending data, whether it is repeatedly sent, whether the endorsement signature meets the requirements of the endorsement policy, etc. When all verifications are passed, it will be marked as valid and written into the ledger. Its flow is shown in Figure 16.

system node server

CA node-consortium chain requires participants to register their identity first, which is the identity of the participant in the blockchain network. The CA node mainly provides the members in the network with identity information based on digital certificates, and can generate or cancel the identity certificates of the members. The members in the network are divided into ordinary members and administrators. The administrator has the right to modify the organization configuration.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features thereof can be equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present invention. scope.

Claims (10)

1. A distributed electronic mailbox system based on coinless blockchain technology, characterized in that it includes a client, a non-system node server, and a system node server; the three are connected through blockchain network communication; Among them, the client includes a client core module and a client platform interface; the client core module includes a user registration module, a user login module, an address book management module, a letter writing and email sending module, a sent module, an inbox module, an account Management module, advertisement module and exit module; the user registration module is used for the creation of user information; the user login module is used for user information verification; the address book management module is used for the addition, deletion, modification and checking of contact names, public keys, and email addresses; writing The letter and send mail module is used for text editing, letter encryption, mail sending and broadcasting; the sent module is used for users to view and retrieve sent mail; the inbox module is used for received letter decryption and mail retrieval; The account management module is used for user information modification and key management; the advertisement module is used for the push and update of advertisements; the exit module is used to realize the function of the user exiting the client; The client platform interface includes the user registration login window, the address book management window, the writing and sending email windows, the sent window, the inbox window, and the personal account management window. Login password, generate or import the user's private key, public key, email address/on-chain address; after a registered user successfully logs in to the client, create a personal address book through the address book management window, and add the names, public keys, and email addresses of other users /Add the address on the chain to the mail address list; edit the subject and content of the letter through the writing and sending mail windows, add the recipient address, and encrypt the content of the letter and send it to the recipient address in the blockchain network; View and retrieve emails after sending in the sending window; decrypt, view and retrieve emails from other addresses through the inbox window; modify user names and passwords, and manage keys through the account management window; The non-system node server includes several endorsement nodes, ordering nodes and confirmation nodes; the email sending request sent by the client is checked for validity, and after endorsement, sorting, and confirmation, it is written into the block ledger; The system node server includes a CA node, and the CA node is used to provide the identity information of the network node and implement authority management. 2. a kind of distributed electronic mailbox system based on coinless block chain technology according to claim 1, is characterized in that, described block chain is the distributed structure of P2P network, has membership and authority management function The alliance chain does not involve any coins and tokens. 3. a kind of distributed electronic mailbox system based on coinless block chain technology according to claim 1, is characterized in that, mailbox system is a decentralized system, and the damage or loss of any small part of nodes in the network does not affect operation of the system. 4. A distributed electronic mailbox system based on a currencyless blockchain technology according to claim 1, characterized in that, all the mail information data in the mailbox system are uploaded to the chain. 5. A kind of distributed electronic mailbox system based on coinless block chain technology according to claim 1, it is characterized in that, in the mailbox system, by encrypting the subject and content of the letter and recording on the block chain, and Using asymmetric cryptography to ensure the security of email message data transmission and access. 6. A distributed electronic mailbox system based on a coinless block chain technology according to claim 1, wherein the operation of the mailbox system is attached to the block chain, and the non-system nodes of the alliance chain are The server performs mail delivery, and the advertiser's cost of advertising is used as the postage fee. When the user uses the client with advertisements, the mail is sent free of charge. 7. a kind of distributed electronic mailbox system based on coinless block chain technology according to claim 1, is characterized in that, the user in described mailbox system can extract and decrypt the mail information sent to one's own address, reach The purpose of checking the letter. 8. A distributed electronic mailbox system based on coinless blockchain technology according to claim 1, wherein any sensitive information of users in the mailbox system is stored in the client and will not be uploaded to in any server. 9. a kind of distributed electronic mailbox system based on coinless block chain technology according to claim 1, is characterized in that, described client comprises desktop application end or mobile phone mobile end, client is responsible for the sending of mail information, Retrieval and reception of block data. 10. A distributed electronic mailbox system based on coinless blockchain technology according to claim 1, wherein the client in the mailbox system stores the plaintext of all passwords and keys in a memory area, After the user exits the client, all data in the memory area is automatically cleared, and the rest of the client data is stored in the client's local database storage area.