CN110689349B - Method and device for storing and searching transaction hash value in blockchain - Google Patents

Abstract

The invention discloses a method and a device for storing and searching transaction hash values in a blockchain, wherein the method comprises the following steps: the client acquires a transaction hash value of an nth transaction initiated by a user on the client and an index parameter of the nth transaction; the client acquires an N-1 state character string corresponding to the index parameter; the client takes the N-1 state character string and the transaction hash value of the nth transaction as the nth data to be encrypted; the client determines an nth key and nth index position information according to the nth state character string and the search token of the index parameter; and the client encrypts the data to be encrypted into an nth ciphertext by using the nth key, and establishes a unique mapping relation between the nth index position information and the nth ciphertext. When the method is applied to financial science and technology (Fintech), the storage of the transaction hash value in the method is safer, and the searchability is reserved during storage.

Description

Method and device for storing and searching transaction hash value in blockchain

technical field

The present invention relates to the fields of financial technology (Fintech) and blockchain (Blockchain), in particular to a method and device for storing and searching transaction hash values in the blockchain.

Background technique

With the development of computer technology, more and more technologies (big data, distributed, blockchain (Blockchain), artificial intelligence, etc.) are applied in the financial field, and the traditional financial industry is gradually transforming into financial technology (Fintech). At present, in the blockchain field of financial technology, the search for transactions is often involved. After each transaction is executed, a transaction hash value that uniquely identifies the transaction will be generated. At present, the general way to search the user's transaction log is to search according to the user's transaction hash value, so the storage security of the user's transaction hash value is very important.

In the prior art, there are mainly two ways to store the transaction hash value. The first is to store the user’s transaction hash value in plain text. Obviously, this method is easy to cause the transaction hash value to be leaked; the second is to store the user’s transaction hash value After the value is encrypted, the transaction hash value is stored as ciphertext, but in this way, the transaction hash value cannot be searched based on the index parameter on the ciphertext. Therefore, the existing technology cannot not only satisfy the storage security of the transaction hash value, but also search for the corresponding transaction hash value according to the index parameters, which is an urgent problem to be solved.

Contents of the invention

The embodiment of the present application provides a transaction hash value storage and search method and device in the blockchain, which solves the problem that the prior art cannot satisfy the storage security of the transaction hash value, and can also search for the corresponding transaction hash value according to the index parameters. Issues with transaction hashes.

In the first aspect, the embodiment of the present application provides a transaction hash value storage method in the blockchain: the client obtains the transaction hash value and the Nth transaction hash value of the Nth transaction initiated by the user on the client The index parameter of the transaction; the index parameter is a keyword determined from the transaction information of the transaction for the transaction log search; N is a positive integer; the client obtains the N-1th state character corresponding to the index parameter string; the N-1th state string is generated for the N-1th transaction; the client uses the N-1th state string and the transaction hash value of the Nth transaction as the first N data to be encrypted; the client generates the Nth state string, and determines the Nth key and the Nth index position information according to the search token of the Nth state string and the index parameter; the client Using the Nth key to encrypt the Nth data to be encrypted into an Nth ciphertext, and establishing a unique mapping relationship between the Nth index position information and the Nth ciphertext.

In the above method, after the client obtains the transaction hash value of the Nth transaction initiated by the user on the client and the N-1th state string corresponding to the index parameter of the Nth transaction, then according to the Nth The search token of the status character string and the index parameter, determine the Nth key and the Nth index position information; and use the Nth key to encrypt the Nth data to be encrypted into the Nth ciphertext, because the Nth- 1 The state string is generated for the N-1th transaction, that is to say, for each N, the Nth ciphertext requires the participation of the N-1th state string, which is generated in an interlocking manner The confidentiality of the plaintext is relatively high; in addition, since the unique mapping relationship between the Nth index position information and the Nth ciphertext is established, the Nth ciphertext can be searched through the Nth index position information, therefore, the transaction in the above method Storage of hashes is more secure while preserving searchability when stored.

In an optional implementation manner, the client uses the N-1th state string and the transaction hash value of the Nth transaction as the Nth data to be encrypted, including: the client uses the The character string concatenated by the N-1th state string and the transaction hash value of the Nth transaction is used as the Nth data to be encrypted; the client uses the Nth key to encrypt the Nth Encrypting the data to be encrypted into an Nth ciphertext includes: performing a bit operation result of the Nth data to be encrypted and the Nth key as the Nth ciphertext according to a preset bit operation.

In the above method, the client concatenates the N-1th state string and the transaction hash value of the Nth transaction as the Nth data to be encrypted, and passes the preset bit The Nth ciphertext is obtained through the operation, so that the Nth data to be encrypted is encrypted in a simple and efficient way.

In an optional implementation manner, the client determines the Nth key and the Nth index location information according to the Nth state string and the search token of the index parameter, including: the client sends the The result of mapping the Nth state string and the search token of the index parameter according to the first preset hash algorithm is used as the Nth key; the client uses the Nth state string and the index The result of mapping the search token of the parameter according to the second preset hash algorithm is used as the Nth index position information; the first hash algorithm and the second hash algorithm are different hash algorithms.

In the above method, the client determines the Nth key and the Nth index position respectively through different first hash algorithms and second hash algorithms according to the Nth state string and the search token of the index parameter Information, so as to establish a mapping relationship with the Nth state string and the search token of the index parameter, and enhance the confidentiality through different hash algorithms.

In the second aspect, the present application provides a transaction hash value search method in the block chain, including: the index server obtains the search token and the Nth state string of the index parameter from the client; the index parameter is obtained from the transaction The keywords used to search the transaction log are determined in the transaction information; N is a positive integer; the Nth status character string is generated when the user initiates the Nth transaction on the client; the index server according to The search token of the index parameter and the Nth state character string are used to obtain the Nth index position information of the index parameter; the Nth index position information is uniquely mapped to the Nth ciphertext; the Nth ciphertext is the ciphertext encrypted by the client to the transaction hash value of the Nth transaction; the index server obtains the Nth index uniquely mapped to the Nth index location information according to the Nth index location information Ciphertext; the index server generates the Nth key according to the search token and the Nth status character string; the index server decrypts the Nth ciphertext into the Nth key according to the Nth key Data to be encrypted; the index server extracts the transaction hash value of the Nth transaction according to the Nth data to be encrypted, so that the search for the transaction hash value of the Nth transaction is completed.

In the above manner, the index server obtains the search token and the Nth state string of the index parameter from the client, and obtains the Nth state string of the index parameter according to the search token of the index parameter and the Nth state string. Index position information. Since the Nth index position information is uniquely mapped to the Nth ciphertext, the Nth ciphertext can be searched according to the Nth index position information, and the Nth ciphertext can be generated by searching the token and the Nth state string N key, and then use the N key to decrypt the Nth ciphertext into the Nth data to be encrypted, and extract the transaction hash value of the Nth transaction, thus realizing the Nth transaction A search of transaction hashes.

In an optional implementation manner, the index server extracts the N-1th state character string according to the Nth data to be encrypted; The N-1 status string is used to obtain the N-1th index position information of the index parameter; the index server obtains the N-1th index position information uniquely mapped to the N-1th index position information according to the N-1th index position information. N-1 ciphertext; the index server decrypts the N-1th ciphertext into N-1th data to be encrypted according to the search token and the N-1th state character string; the indexing server According to the N-1th data to be encrypted, the transaction hash value of the N-1th transaction is extracted, so that the search for the transaction hash value of the N-1th transaction is completed.

In the above manner, the index server extracts the N-1th state character string according to the Nth data to be encrypted, and obtains the N-1th index position information of the index parameter, and obtains the N-th 1 The N-1th ciphertext uniquely mapped to the index position information, that is to say, the index server can obtain the N-1th ciphertext based on the Nth to-be-encrypted data after decrypting the Nth to-be-encrypted data, and extract the N-th ciphertext The transaction hash value at the time of the N-1 transaction, so that the search for the transaction hash value at the time of the N-1th transaction is completed.

In an optional implementation manner, the Nth ciphertext is a bit operation result of the data to be encrypted and the Nth key according to a preset bit operation; the index server converts the Nth key to the The Nth ciphertext is decrypted into the Nth data to be encrypted: the index server calculates according to the preset bit, and uses the bit operation result of the Nth ciphertext and the Nth key as the Nth data to be encrypted Encrypt data.

In the above method, since the Nth ciphertext is the bit operation result of the data to be encrypted and the Nth key according to the preset bit operation, the index server calculates the Nth ciphertext according to the preset bit operation. The text decryption is to use the bit operation result of the Nth ciphertext and the Nth key as the Nth data to be encrypted.

In a third aspect, the present application provides a transaction hash value storage device in a block chain, including: an acquisition module, configured to acquire the transaction hash value and the transaction hash value of the Nth transaction initiated by the user on the client The index parameter of the Nth transaction; the index parameter is a keyword determined from the transaction information of the transaction for the transaction log search; obtain the N-1th state string corresponding to the index parameter; the Nth The -1 status string is generated for the N-1th transaction; N is a positive integer; the encryption module is used to use the N-1th status string and the transaction hash value of the N-th transaction as the first N data to be encrypted; generate the Nth state character string, and determine the Nth key and the Nth index position information according to the search token of the Nth state character string and the index parameter; use the Nth key to The Nth data to be encrypted is encrypted into an Nth ciphertext, and a unique mapping relationship between the Nth index position information and the Nth ciphertext is established.

In an optional implementation manner, the encryption module is specifically configured to: concatenate the N-1th state character string and the transaction hash value of the Nth transaction as the character string to be used as the Nth Encrypting data: according to a preset bit operation, using a bit operation result of the Nth data to be encrypted and the Nth key as the Nth ciphertext.

In an optional implementation manner, the encryption module is specifically configured to: map the Nth state character string and the search token of the index parameter according to a first preset hash algorithm as the Nth key; the result of mapping the Nth state string and the search token of the index parameter according to a second preset hash algorithm as the Nth index position information; the first hash algorithm and the The second hash algorithm is a different hash algorithm.

For the above-mentioned third aspect and the beneficial effects of each embodiment of the third aspect, reference may be made to the above-mentioned first aspect and the beneficial effects of each embodiment of the first aspect, which will not be repeated here.

In a fourth aspect, the present application provides a transaction hash value storage device in a block chain, including: an acquisition module, which is used to acquire a search token and an Nth state character string of an index parameter from a client; the index parameter is Determine the keywords used to search the transaction log from the transaction information of the transaction; the Nth status character string is generated when the user initiates the Nth transaction on the client; N is a positive integer; according to the The search token of the index parameter and the Nth state character string to obtain the Nth index position information of the index parameter; the Nth index position information is uniquely mapped to the Nth ciphertext; the Nth ciphertext is The client encrypts the ciphertext of the transaction hash value of the Nth transaction; according to the Nth index position information, obtains the Nth ciphertext uniquely mapped to the Nth index position information; a decryption module , for generating an Nth key according to the search token and the Nth state string; decrypting the Nth ciphertext into the Nth data to be encrypted according to the Nth key; according to the Nth key For N data to be encrypted, the transaction hash value at the time of the Nth transaction is extracted, so that the search for the transaction hash value at the time of the Nth transaction is completed.

In an optional implementation manner, the obtaining module is further configured to: extract the N-1th state character string according to the Nth data to be encrypted; according to the search token of the index parameter and the N-1 status character string, to obtain the N-1th index position information of the index parameter; according to the N-1th index position information, to obtain the N-1th index uniquely mapped to the N-1th index position information text; the decryption module is also used to: according to the search token and the N-1 state string, decrypt the N-1th ciphertext into the N-1th data to be encrypted; according to the N-1th state string For N-1 data to be encrypted, the transaction hash value of the N-1th transaction is extracted, so that the search for the transaction hash value of the N-1th transaction is completed.

In an optional implementation manner, the Nth ciphertext is a bit operation result of the data to be encrypted and the Nth key according to a preset bit operation; the index server converts the Nth key to the The Nth ciphertext is decrypted into the Nth data to be encrypted: the index server calculates according to the preset bit, and uses the bit operation result of the Nth ciphertext and the Nth key as the Nth data to be encrypted Encrypt data.

For the beneficial effects of the above fourth aspect and various embodiments of the fourth aspect, reference may be made to the above second aspect and the beneficial effects of each embodiment of the second aspect, which will not be repeated here.

In the fifth aspect, the embodiment of the present application provides a computer device, including a program or an instruction. When the program or instruction is executed, it is used to execute the above-mentioned first aspect and the various embodiments of the first aspect or the second aspect and the second aspect. Methods of various embodiments of the aspect.

In the sixth aspect, the embodiments of the present application provide a storage medium, including programs or instructions, when the programs or instructions are executed, to execute the above-mentioned first aspect and the various embodiments of the first aspect or the second aspect and the second aspect Methods of various embodiments of the aspect.

Description of drawings

Figure 1 is a schematic structural diagram of the blockchain;

Figure 2 is a schematic flow chart of event calling and generating logs;

Fig. 3 is a schematic diagram of the process of a transaction hash value storage and search method provided by the embodiment of the present application;

Fig. 4 is a schematic flow chart of the steps of a transaction hash value storage method provided by the embodiment of the present application;

Fig. 5 is a schematic flow chart of the steps of a transaction hash value search method provided by the embodiment of the present application;

FIG. 6 is a schematic structural diagram of a transaction hash value storage device provided by an embodiment of the present application;

FIG. 7 is a schematic structural diagram of a transaction hash value search device provided by an embodiment of the present application.

Detailed ways

In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be understood that the embodiments of the present application and the specific features in the embodiments are detailed descriptions of the technical solution of the present application. To illustrate, rather than limit, the technical solutions of the present application, the embodiments of the present application and the technical features in the embodiments can be combined without conflict.

The nouns appearing in the embodiments of the present application are firstly explained below.

Blockchain: As shown in Figure 1, the blockchain is a chain composed of a series of blocks. In addition to recording the data of this block, each block also records the hash (Hash) value of the previous block. Through this form a chain. There are two core concepts of the blockchain, one is cryptography technology, and the other is the idea of decentralization. Based on these two concepts, the historical information on the blockchain cannot be tampered with.

Smart Contract: A smart contract is a computer protocol designed to communicate, verify or enforce a contract in an informational manner. Smart contracts allow for trusted transactions without third parties, which are traceable and irreversible. The specific form of a smart contract is the code deployed on the blockchain to complete a specific function.

Log: The log is a special kind of data defined by Ethereum. The log is associated with the smart contract and is part of the transaction receipt. Transactions that contain a particular log are unique, and transactions in Ethereum are generally represented by their transaction hash. Logs are generated by clients when executing transactions and they can be retrieved in blockchain storage. As long as a block is accessible, its associated logs are also accessible. However, in the contract, the log and event data cannot be directly accessed (even the contract that created the log), and generally the log can only be accessed through the transaction hash value. The log includes two parts: topic and data. The topic part is used for quick search, while the data part is used to store the original log.

Event: An event is an interface provided by the Ethereum Virtual Machine based on the log mechanism. By triggering an event, a log can be generated and written into the blockchain. In the development of smart contracts, the event mechanism is usually used to record user operation records. For example, define a transfer event event transfer(address indexed from, address indexed to, uint value), when the event is triggered, the parameters from, to and value will generate a log, which will be written to the blockchain. The application program can monitor or invoke events through the remote procedure call (remote procedure call, RPC) interface of the Ethereum client, as shown in Figure 2.

Parameters of the event: When defining an event, the parameters of the event need to be specified. There are two types of parameters, one is modified by indexed, and the other is not modified by indexed. The difference between these two parameters is that the former will be stored in the topic field of the log, while the latter will be stored in the data field of the log. The topic field of the log can be used for searching, but the data field cannot be used for searching. For example, if you define a transfer event event transfer(address indexed from, address indexed to, uint value), when the event is triggered, the parameters from, to and value will be written into the log of the blockchain. Users can filter logs by from or to, such as "search for all records where from is equal to address A (equivalent to searching for transfer-out records of address A)", but cannot filter by value.

Hash function: A hash function is also called a hash function, which converts an input of any length into a fixed-length output through a hash algorithm, and the output is a hash value. This conversion is a compression map, that is, the space of the hash value is usually much smaller than the space of the input, and different inputs may hash to the same output, so it is impossible to determine the unique input value from the hash value. A hash function can be formally defined as: H:(0,1) ^x →(0,1) ⁿ . Where x is an arbitrary length, and n is a fixed length.

Pseudorandom function: A pseudorandom function is a way of generating a random string of characters. Unlike the hash function, the input of the pseudo-random function includes a key k and a message m, and k is kept secret. The output of the pseudo-random function is jointly determined by k and m. The pseudorandom function can be formally defined as F:(0,1) ^λ ×(0,1) ^x →(0,1) ⁿ . where λ is the length of the key k, x is the length of the message m, and n is the length of the output. In this patent, the pseudo-random is implemented by using a hash function, that is, splicing the key k and the message m together as the input of the function, F(k,m)=H(k||m). In the embodiment of the present application, || represents a connection, and k||m represents a result of connecting k and m.

Search tokens: Search tokens are a variant of search keywords. When searching, in order to ensure the confidentiality of the searched keyword, the user needs to process the keyword first. The process of generating a search token requires the participation of the user's key to ensure that an attacker cannot forge it. The search token will not reveal any information about the original keyword. In searchable encryption, a pseudo-random function is usually used to generate a search token corresponding to the search keyword. If the keyword to be searched is w and the user key is k, then the search token is F(k,w).

During the operation of financial institutions (banking institutions, insurance institutions or securities institutions) (such as bank loan business, deposit business, etc.), transaction searches are often involved. After each transaction is executed, a transaction hash value that uniquely identifies the transaction will be generated. At present, the general way to search the user's transaction log is to search according to the user's transaction hash value, so the storage security of the user's transaction hash value is very important.

In the prior art, there are mainly two ways to store the transaction hash value. The first is to store the user’s transaction hash value in plain text. Obviously, this method is easy to cause the transaction hash value to be leaked; the second is to store the user’s transaction hash value After the value is encrypted, the transaction hash value is stored as ciphertext, but in this way, the transaction hash value cannot be searched based on the index parameter on the ciphertext. Therefore, the existing technology cannot not only satisfy the storage security of the transaction hash value, but also be able to search for the corresponding transaction hash value according to the index parameters, which will also lead to a long transmission delay of the task scheduling signal. This situation does not meet the needs of financial institutions such as banks, and cannot guarantee the efficient operation of various businesses of financial institutions.

Based on the above analysis, the present invention designs a solution in the blockchain that supports the storage and search of transaction hash values for the existing event mechanism. This scheme ensures that during the entire process of user interaction with the blockchain, the transmitted data is in ciphertext. In addition, users can search data in the topic field and data field at the same time.

This scheme uses a searchable encrypted storage scheme with forward security properties. As shown in Figure 3, each keyword corresponds to a state chain. A node in the state chain corresponds to a file containing the keyword, and each node is uniquely identified by the state st. In the Update phase, the client first generates a new state st _c+1 , and then according to the keyword w, the search token t _w of the keyword w, the file name ind, the operation type op (including adding and deleting), etc. The information generates a new node and adds the node to the state chain. When searching, only need to know t _w and st _c+1 to get the last node, so as to traverse to get all the nodes on the state chain.

In this application, the file name corresponds to the transaction hash value, and the keyword corresponds to the parameter modified by indexed in the user-defined event. For example, define a transfer event event transfer(address indexed from, address indexed to, uint value). When you want to search for logs from=“0x1234..”, you only need to search for all transaction hash values with keywords w=“0x1234…”, and then retrieve the corresponding logs from these transaction receipts. In addition, in this application, there is only one type of operation, that is, op must be increment.

The program mainly includes three main bodies:

Blockchain: Any blockchain with an event mechanism for distributed storage of data.

User: Generate data and write it into the database in the form of triggering events, and retrieve events that meet certain conditions. It should be noted that in the present invention, the user is required to have a certain storage capacity for storing some information related to keywords. According to different application scenarios, the user's storage form is also different: for example, in the application of the client/server (Client/Server, C/S) architecture, the server can be used; in the browser/server structure (Browser/Server, B/ S) The data (cookie) stored in the user's local terminal by the browser can be used in the application of the framework.

Index server: When the user's storage capacity is insufficient, the index location information can be outsourced to a trusted server. When searching, the index server first searches for the transaction hash value that meets the conditions, and then the user queries the specific log according to the transaction hash value.

Before storing or searching transaction hash values, system initialization is required. The process of system initialization is described in detail below:

The user determines the long-term key k.

A long-term key is essentially a binary string. The length of the key is related to the system parameter λ. For example, when λ=1024, k is a binary string with a length of 1024. The long-term key needs to be kept safe by the user, and will be used to generate the search token corresponding to the keyword.

The user initializes the local storage structure.

For example, the storage structure is a data structure of a key-value (map) structure, wherein the key (key) is a keyword, and the value (value) is the latest state corresponding to the keyword.

In the following, with reference to FIG. 4 and FIG. 5 , a schematic flowchart of the steps of a method for storing and searching transaction hash values provided by the embodiment of the present application will be introduced in detail.

The steps of a transaction hash value storage method provided in the embodiment of this application are as follows:

Step 401: the client terminal obtains the transaction hash value of the Nth transaction initiated by the user on the client terminal and the index parameter of the Nth transaction.

The index parameter is a keyword determined from the transaction information of the transaction for searching the transaction log; N is a positive integer.

Step 402: The client acquires the N-1th state string corresponding to the index parameter.

The N-1th status string is generated for the N-1th transaction.

Step 403: The client uses the N-1th status string and the transaction hash value of the Nth transaction as the Nth data to be encrypted.

Step 404: The client generates an Nth state string, and determines the Nth key and the Nth index position information according to the Nth state string and the search token of the index parameter.

Step 405: The client encrypts the Nth data to be encrypted into an Nth ciphertext by using the Nth key, and establishes a unique mapping relationship between the Nth index position information and the Nth ciphertext.

In step 401, the client refers to the client host running the client front-end software. In the Nth transaction, the count of N is for an event and a specific parameter value of an index parameter of the event. For example, the Nth transaction may be the Nth triggering corresponding transaction of the transfer event under the condition of "from=A". When it is necessary to search the transaction log according to the index parameter, you can assign a specific value to the index parameter to search, for example, search for the transfer event according to "form=A".

In the above steps 401 to 405, an optional implementation of encrypting the Nth ciphertext is as follows:

The client concatenates the N-1th state string and the transaction hash value of the Nth transaction as the Nth data to be encrypted; according to the preset bit operation, the A bit operation result of the Nth data to be encrypted and the Nth key is used as the Nth ciphertext. For example, the preset bit operation is an exclusive OR bit operation.

An optional implementation manner of step 404 is as follows:

The client uses the result of mapping the Nth state string and the search token of the index parameter according to the first preset hash algorithm as the Nth key; the client uses the Nth The result of mapping the status string and the search token of the index parameter according to the second preset hash algorithm is used as the Nth index position information; the first hash algorithm and the second hash algorithm are different hash algorithm.

Correspondingly, the steps of a transaction hash value search method provided in the embodiment of the present application are as follows:

Step 501: The indexing server acquires the search token and the Nth status string of the indexing parameters from the client.

The index parameter is determined from the transaction information of the transaction to be used for the keyword search of the transaction log; the Nth status character string is generated when the user initiates the Nth transaction on the client; N is positive integer.

Step 502: The index server obtains the Nth index position information of the index parameter according to the search token of the index parameter and the Nth status character string.

The Nth index position information is uniquely mapped to the Nth ciphertext; the Nth ciphertext is the ciphertext encrypted by the client to the transaction hash value of the Nth transaction.

Step 503: The index server obtains the Nth ciphertext uniquely mapped to the Nth index location information according to the Nth index location information.

Step 504: The index server generates an Nth key according to the search token and the Nth state string.

The index server decrypts the Nth ciphertext into Nth data to be encrypted according to the Nth key.

Step 505: The index server extracts the transaction hash value of the Nth transaction according to the Nth data to be encrypted, so as to complete the search for the transaction hash value of the Nth transaction.

It should be noted that the search token, the Nth state character string, the Nth index position information, the Nth ciphertext, the Nth key and the Nth data to be encrypted in the above 501-505. Corresponding to steps 401 to 404.

After step 505, you can continue to search for the transaction hash value of the N-1th transaction, the specific implementation is as follows:

The index server extracts the N-1th state string according to the Nth data to be encrypted; the index server obtains the N-1th state string according to the search token of the index parameter and the N-1th state string The N-1th index position information of the index parameter; the index server obtains the N-1th ciphertext uniquely mapped to the N-1th index position information according to the N-1th index position information; the The index server decrypts the N-1th ciphertext into the N-1th data to be encrypted according to the search token and the N-1th status string; Encrypt the data, and extract the transaction hash value of the N-1th transaction, so that the search for the transaction hash value of the N-1th transaction is completed.

In step 504, an optional implementation manner is: the Nth ciphertext is the bit operation result of the data to be encrypted and the Nth key according to preset bit operations; step 504 can be performed in the following steps:

The index server calculates according to the preset bit, and uses the bit operation result of the Nth ciphertext and the Nth key as the Nth data to be encrypted.

The following uses specific examples to further illustrate a method for storing and searching transaction hash values provided by the embodiment of the present application.

When the event is triggered, the storage process of the transaction hash value is as follows. It should be noted that the following process is for an index parameter of an event:

Step 401 can be specifically divided into the following first step and second step:

Step 1: Use the parameter modified with indexed in the event as the keyword w.

Specifically, a pseudo-random function F can be used to calculate the search token tw=F(k,w) with long-term keys and keywords as parameters.

For example, a transfer event is defined in the smart contract, event transfer(address indexed from, address indexed to, uint value). When the transfer event is triggered, emit transfer("0x1111...ffffcccc", "0x50...sd5adb20", 100), that is, the address "0x1111...ffffcccc" transfers 100eth to the address "0x50...sd5adb20".

Since the parameters from and to are modified by indexed, it means that the user hopes to search with these two parameters as keywords in the future (for example, filter out all transfer records whose address is "0x1111...FFFFCCCC"). The first step above is performed for each of the two index parameters: the user generates two search tokens t _w =F(k,"0x1111...ffffcccc") and t _w =F(k,"0x50...sd5adb20") .

Step 2: The user gets the transaction hash value of the transaction.

Specifically, after the user initiates a transaction by calling the function, a transaction hash value of the transaction will be returned, and the callback function can be used to capture the hash value. The hash value can also be calculated manually, assuming that the transaction tx=[nonce,gasPrice,gas,to,value,data,v,r,s], where nonce is a random number, gasPrice is the current gas price, and gas is the The maximum amount of gas that can be used in a transaction is limited, to is the address of the receiver (in the scenario of this application, it can be a contract address), value is the amount of ether sent by the transaction, data is the data of the transaction, v, r and s can be Represents an elliptic curve digital signature algorithm (elliptic curve digital signature, ECDSA) signature. When calculating the hash value of a transaction, the transaction is first encoded with a recursive length prefix (RLP), and then the encoded data is used to calculate the transaction hash value. For example, the transaction hash value is calculated by keccak256, that is, the transaction hash value is simply expressed as: hash(tx)=keccak256(rlp.encode(tx)), and hash(tx) is a 2048-bit string.

Step 3: The user checks whether there is a record about w in the local storage, and executes step 402 .

Step 402 is divided into two situations:

The first type: if there is no record about w, it is determined that the index parameter is the first occurrence, and the preset special symbol ⊥ (representing the first occurrence of the keyword) is used as the N-1th state string (in Figure 3 of st _c ).

The second type: if there is a record about w, it is determined that the index parameter is not the first occurrence, and the randomly generated character string is used as the N-1th state character string.

The length of the status character string can be set by the system parameter λ, for example, when λ=1024, the status character string is a binary string with a length of 1024.

Step 4: Step 403 is executed.

For example, concatenate the N-1th state string and the transaction hash value to obtain the Nth data to be encrypted, that is, p=(⊥||hash(tx)); or concatenate st _c and the transaction hash value to obtain The Nth data to be encrypted, that is, p=(st _c ||hash).

Step 5: Execute steps 404 to 405.

For example, u=H ₁ (t _w ||st _c+1 ), u is the Nth index position information, st _c+1 is the Nth state character string, and H ₁ is the first hash algorithm.

长度不足时用0补齐)。这里的H₂为第二哈希算法。Calculate the Nth key key=H ₂ (t _w ||st _c+1 ), use the preset bit operation, such as XOR bit operation to encrypt the data to be encrypted to obtain the Nth ciphertext e (ie

If the length is insufficient, fill it with 0). Here H ₂ is the second hash algorithm.

_H1 and _H2 must be two different hash functions, such as H1 is the SHA256 hash function, and H2 is the MD5 hash function.

Step 6: The user stores the Nth state string st _c+1 corresponding to the index parameter w into the user's storage structure, and stores (u, e) in the index server. At this time, the storage of the index server is shown in Figure 3, which shows the index situation where an index parameter takes a specific parameter value (such as "0x1111...FFFFCCCC"), and each node represents a log containing the parameter value. Since the log is stored in the transaction receipt, in this application each node saves a transaction hash value hash(tx) corresponding to the log.

The search process for the transaction hash value is as follows. It should be noted that the following process is for an index parameter of an event:

Step 1: The user checks whether there is a record about w in the local storage. If not, it means that there is no log about the index parameter, and returns empty directly.

Step 2: If there is a record about w, go to step 501.

Specifically, fetch a certain state string, such as st _c . In particular, st _c is the latest state string of w. The search token t _w =F(k,w) is computed using the long-term key, where F is a pseudo-random function. The client submits t _w and st _c to the index server;

Step 3: Execute steps 502 to 503.

For example, after receiving (tw, stc), the index server obtains the Nth index position information through u=H ₁ (t _w ||st _c-1 ). Take out the record ciphertext e about stc.

Step 4: Execute steps 504 to 505.

H₂(t_w||st_c)为第N密钥；p为第N待加密数据。其中p＝(stc-1,hash(tx))；hash(tx)即为满足条件的事件所生成的日志所在的交易的哈希值，将其存储在结果R中。Decrypt e, that is,

H ₂ (t _w ||st _c ) is the Nth key; p is the Nth data to be encrypted. Where p=(stc-1,hash(tx)); hash(tx) is the hash value of the transaction where the log generated by the event meeting the conditions is located, and it is stored in the result R.

Step 5: Obtain the log corresponding to the parameter value of the index parameter.

The index server uses stc-1 to calculate the next position u=H ₁ (t _w ||st _c-1 ), and takes out the corresponding ciphertext. If so, continue to loop through Step 3, update R, and finally return the search result R, which is the set of hash values of all transactions that meet the conditions.

After receiving R, the user takes each transaction hash value in R as input, and uses the corresponding function such as (web3.eth.getTransactionReceipt) function to obtain the receipt of the transaction, and then obtain the specific log.

As shown in Figure 6, the present application provides a transaction hash value storage device in the block chain, including: an acquisition module 601, which is used to acquire the transaction hash value and the transaction hash value of the Nth transaction initiated by the user on the client The index parameter of the Nth transaction; the index parameter is a keyword determined from the transaction information of the transaction for the transaction log search; obtain the N-1th state string corresponding to the index parameter; the The N-1 state string is generated for the N-1th transaction; N is a positive integer; the encryption module 602 is used to combine the N-1th state string and the transaction hash value of the Nth transaction As the Nth data to be encrypted; generate the Nth status string, and determine the Nth key and the Nth index position information according to the Nth status string and the search token of the index parameter; use the Nth password The key encrypts the Nth data to be encrypted into an Nth ciphertext, and establishes a unique mapping relationship between the Nth index position information and the Nth ciphertext.

In an optional implementation manner, the encryption module 602 is specifically configured to: concatenate the N-1th state character string and the transaction hash value of the Nth transaction into a character string as the Nth The data to be encrypted: according to the preset bit operation, the bit operation result of the Nth data to be encrypted and the Nth key is used as the Nth ciphertext.

In an optional implementation manner, the encryption module 602 is specifically configured to: use the result of mapping the Nth state string and the search token of the index parameter according to a first preset hash algorithm as the Nth N key; the result of mapping the Nth state string and the search token of the index parameter according to a second preset hash algorithm as the Nth index position information; the first hash algorithm and The second hash algorithm is a different hash algorithm.

As shown in Figure 7, the application provides a transaction hash value storage device in the block chain, including: an acquisition module 701, which is used to acquire the search token and the Nth state string of the index parameter from the client; the index parameter It is determined from the transaction information of the transaction that the keyword used for searching the transaction log is determined; the Nth status character string is generated when the user initiates the Nth transaction on the client; N is a positive integer; according to The search token of the index parameter and the Nth state character string are used to obtain the Nth index position information of the index parameter; the Nth index position information is uniquely mapped to the Nth ciphertext; the Nth ciphertext is the ciphertext encrypted by the client to the transaction hash value of the Nth transaction; according to the Nth index location information, obtain the Nth ciphertext uniquely mapped to the Nth index location information; decrypt Module 702, configured to generate an Nth key according to the search token and the Nth state character string; decrypt the Nth ciphertext into Nth data to be encrypted according to the Nth key; For the Nth data to be encrypted, the transaction hash value at the time of the Nth transaction is extracted, so that the search for the transaction hash value at the time of the Nth transaction is completed.

In an optional implementation manner, the acquiring module 701 is further configured to: extract the N-1th state string according to the Nth data to be encrypted; according to the search token of the index parameter and the The N-1th status string, obtaining the N-1th index position information of the index parameter; according to the N-1th index position information, obtaining the N-1th index position information uniquely mapped to the N-1th index position information Ciphertext; the decryption module 702 is also configured to: according to the search token and the N-1th state character string, decrypt the N-1th ciphertext into the N-1th data to be encrypted; according to the For the N-1th data to be encrypted, the transaction hash value of the N-1th transaction is extracted, so that the search for the transaction hash value of the N-1th transaction is completed.

In an optional implementation manner, the Nth ciphertext is a bit operation result of the data to be encrypted and the Nth key according to a preset bit operation; the index server converts the Nth key to the The Nth ciphertext is decrypted into the Nth data to be encrypted: the index server calculates according to the preset bit, and uses the bit operation result of the Nth ciphertext and the Nth key as the Nth data to be encrypted Encrypt data.

An embodiment of the present application provides a computer device, including a program or an instruction. When the program or instruction is executed, it is used to execute a transaction hash value storage or search method in the blockchain provided by the embodiment of the present application and Either method is optional.

An embodiment of the present application provides a storage medium, including a program or an instruction. When the program or instruction is executed, it is used to execute a transaction hash value storage or search method in the blockchain provided by the embodiment of the present application and Either method is optional.

Finally, it should be noted that those skilled in the art should understand that the embodiments of the present application may be provided as methods, systems, or computer program products. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, optical storage, etc.) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to the present application. It should be understood that each procedure and/or block in the flowchart and/or block diagram, and a combination of procedures and/or blocks in the flowchart and/or block diagram can be realized by computer program instructions. These computer program instructions may be provided to a general purpose computer, special purpose computer, embedded processor, or processor of other programmable data processing equipment to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing equipment produce a An apparatus for realizing the functions specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to operate in a specific manner, such that the instructions stored in the computer-readable memory produce an article of manufacture comprising instruction means, the instructions The device realizes the function specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

Apparently, those skilled in the art can make various changes and modifications to the present application without departing from the scope of the present application. In this way, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these modifications and variations.

Claims (12)

1. A method of storing a transaction hash value in a blockchain, comprising:

the client acquires a transaction hash value of an nth transaction initiated by a user on the client and an index parameter of the nth transaction; the index parameter is a keyword which is determined from transaction information of transactions and used for searching transaction logs; n is a positive integer;

the client acquires an N-1 state character string corresponding to the index parameter; the N-1 th status string is generated for the N-1 th transaction;

The client takes the N-1 state character string and the transaction hash value of the nth transaction as the nth data to be encrypted;

the client generates an N state character string, and determines an N key and N index position information according to the N state character string and a search token of the index parameter;

and the client encrypts the data to be encrypted into an nth ciphertext by using the nth key, and establishes a unique mapping relation between the nth index position information and the nth ciphertext.

2. The method of claim 1, wherein,

the client takes the N-1 state character string and the transaction hash value of the N transaction as N data to be encrypted, and the method comprises the following steps:

the client-side uses the N-1 state character string and the character string after the transaction hash value of the N transaction is spliced as the N data to be encrypted;

the client encrypts the nth data to be encrypted into an nth ciphertext by using the nth key, including:

and according to a preset bit operation, taking the bit operation result of the N data to be encrypted and the N secret key as the N ciphertext.

3. The method according to claim 1 or 2, wherein the determining, by the client, an nth key and an nth index location information from the nth status string and the search token of the index parameter comprises:

The client uses the N state character string and the search token of the index parameter as the N key according to the mapping result of a first preset hash algorithm;

the client uses the N state character string and the search token of the index parameter as the N index position information according to the mapping result of a second preset hash algorithm; the first preset hash algorithm and the second preset hash algorithm are different hash algorithms.

4. A transaction hash value search method in a blockchain, comprising:

the index server acquires a search token and an Nth state character string of index parameters from the client; the index parameter is a keyword which is determined from transaction information of transactions and used for searching transaction logs; the nth status string is generated when a user initiates an nth transaction on the client; n is a positive integer;

the index server obtains the N index position information of the index parameter according to the search token of the index parameter and the N state character string; the nth index position information is uniquely mapped with the nth ciphertext; the nth ciphertext is a ciphertext obtained by encrypting the transaction hash value of the nth transaction by the client;

The index server obtains the nth ciphertext uniquely mapped by the nth index position information according to the nth index position information;

the index server generates an nth key according to the search token and the nth state character string; the index server decrypts the Nth ciphertext into the Nth data to be encrypted according to the Nth key;

and the index server extracts the transaction hash value of the nth transaction according to the data to be encrypted, so that the transaction hash value of the nth transaction is searched.

5. The method as recited in claim 4, further comprising:

the index server extracts the N-1 state character string according to the N data to be encrypted;

the index server obtains the N-1 index position information of the index parameter according to the search token of the index parameter and the N-1 state character string;

the index server obtains an N-1 ciphertext uniquely mapped by the N-1 index position information according to the N-1 index position information;

the index server decrypts the N-1 ciphertext into the N-1 data to be encrypted according to the search token and the N-1 state character string;

And the index server extracts the transaction hash value of the N-1 th transaction according to the N-1 th data to be encrypted, so that the search of the transaction hash value of the N-1 th transaction is completed.

6. The method according to claim 4 or 5, wherein the nth ciphertext is a bit operation result of the data to be encrypted and the nth key according to a preset bit operation; the index server decrypts the nth ciphertext into nth data to be encrypted according to the nth key, and the method comprises the following steps:

and the index server uses the bit operation result of the N ciphertext and the N key as the N data to be encrypted according to the preset bit operation.

7. A transaction hash value storage device in a blockchain, comprising:

the acquisition module is used for acquiring a transaction hash value of an nth transaction initiated by a user on the client and an index parameter of the nth transaction; the index parameter is a keyword which is determined from transaction information of transactions and used for searching transaction logs; acquiring an N-1 state character string corresponding to the index parameter; the N-1 th status string is generated for the N-1 th transaction; n is a positive integer;

The encryption module is used for taking the N-1 state character string and the transaction hash value of the nth transaction as nth data to be encrypted; generating an N-th state character string, and determining an N-th key and N-th index position information according to the N-th state character string and the search token of the index parameter; and encrypting the data to be encrypted into an nth ciphertext by using the nth key, and establishing a unique mapping relation between the nth index position information and the nth ciphertext.

8. The apparatus of claim 7, wherein the encryption module is specifically configured to:

the N-1 state character string and the character string after the transaction hash value of the N transaction are spliced are used as the N data to be encrypted; and according to a preset bit operation, taking the bit operation result of the N data to be encrypted and the N secret key as the N ciphertext.

9. The apparatus according to claim 7 or 8, wherein the encryption module is specifically configured to:

the N state character string and the search token of the index parameter are used as the N secret key according to the mapping result of a first preset hash algorithm; the N state character string and the search token of the index parameter are used as the N index position information according to the mapping result of a second preset hash algorithm; the first preset hash algorithm and the second preset hash algorithm are different hash algorithms.

10. A transaction hash value search apparatus in a blockchain, comprising:

the acquisition module is used for acquiring the search token and the Nth state character string of the index parameter from the client; the index parameter is a keyword which is determined from transaction information of transactions and used for searching transaction logs; the nth status string is generated when a user initiates an nth transaction on the client; n is a positive integer; acquiring the N index position information of the index parameter according to the search token of the index parameter and the N state character string; the nth index position information is uniquely mapped with the nth ciphertext; the nth ciphertext is a ciphertext obtained by encrypting the transaction hash value of the nth transaction by the client; acquiring the N ciphertext uniquely mapped by the N index position information according to the N index position information;

the decryption module is used for generating an nth key according to the search token and the nth state character string; decrypting the nth ciphertext into the nth data to be encrypted according to the nth key; and extracting the transaction hash value of the nth transaction according to the data to be encrypted, so that the transaction hash value of the nth transaction is searched.

11. A computer device comprising a program or instructions which, when executed, performs the method of any of claims 1 to 3 or 4 to 6.

12. A storage medium comprising a program or instructions which, when executed, perform the method of any one of claims 1 to 3 or 4 to 6.

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