WO2019214070A1 - Encryption method for user communication on block chain, apparatus, terminal device and storage medium - Google Patents

Abstract

Disclosed in the present application are an encryption method for user communication on a block chain, an apparatus, a terminal device and a storage medium. The method for user communication on the block chain comprises: a user A sending first encryption information to a user B; the user B receiving and decrypting the first encryption information to acquire a first random number; the user B sending second encryption information to the user A; the user A receiving and decrypting the second encryption information to acquire a second random number; the user A and the user B performing a key generation algorithm on the basis of the first random number and the second random number to acquire a key (Key) and an initialized variable (IV); and the user A and the user B achieving encrypted communication on the basis of the key (Key) and the initialized variable (IV) by adopting a CBC mode of an AES algorithm. According to the encryption method for user communication on the block chain, the security of point-to-point communication of the users on the block chain system can be guaranteed.

Description

User communication encryption method, device, terminal device and storage medium on blockchain

This application is based on the Chinese Patent Application No. 201810437217.7 filed on May 9, 2018, entitled "User Communication Encryption Method, Device, Terminal Device and Storage Medium on Blockchain", and requires priority.

Technical field

The present application relates to the field of blockchain application, and in particular, to a user communication encryption method, device, terminal device and storage medium on a blockchain.

Background technique

When the user performs peer-to-peer communication on the blockchain system, since the data on the blockchain system is shared, any user on the blockchain system can obtain the communication content of the peer-to-peer communication on the blockchain system, which cannot be guaranteed. The security of peer-to-peer communication on the blockchain system.

Summary of the invention

The embodiment of the present application provides a method, a device, a terminal device, and a storage medium for user communication encryption on a blockchain, so as to solve the problem that the user is insecure for peer-to-peer communication on the current blockchain system.

In a first aspect, an embodiment of the present application provides a method for encrypting user communications on a blockchain, including:

User A sends the first encrypted information to User B;

User B receives the first encrypted information, and obtains a first random number after decryption;

User B sends second encrypted information to user A;

User A receives the second encrypted information, and obtains a second random number after decryption;

User A and user B perform a key generation algorithm based on the first random number and the second random number to obtain a key Key and an initialization variable IV;

User A and user B perform encrypted communication using the CBC mode of the AES algorithm based on the key Key and the initialization variable IV.

In a second aspect, the embodiment of the present application provides a user communication encryption device on a blockchain, including:

a first encryption information sending module, configured for user A to send first encrypted information to user B;

a first random number obtaining module, configured to receive, by the user B, the first encrypted information, and obtain a first random number after decryption;

a second encrypted information sending module, configured for user B to send second encrypted information to user A;

a second random number obtaining module, configured to receive the second encrypted information by the user A, and obtain a second random number after decryption;

a key and initialization variable obtaining module, configured for user A and user B to perform a key generation algorithm based on the first random number and the second random number, to obtain a key Key and an initialization variable IV;

The encrypted communication module is used for user A and user B to perform encrypted communication using the CBC mode of the AES algorithm based on the key Key and the initialization variable IV.

In a third aspect, an embodiment of the present application provides a terminal device, including a memory, a processor, and computer readable instructions stored in the memory and executable on the processor, where the processor executes the computer The following steps are implemented when reading the instruction:

User A sends the first encrypted information to User B;

User B receives the first encrypted information, and obtains a first random number after decryption;

User B sends second encrypted information to user A;

User A receives the second encrypted information, and obtains a second random number after decryption;

User A and user B perform a key generation algorithm based on the first random number and the second random number to obtain a key Key and an initialization variable IV;

User A and user B perform encrypted communication using the CBC mode of the AES algorithm based on the key Key and the initialization variable IV.

In a fourth aspect, the embodiment of the present application provides one or more non-volatile readable storage media storing computer readable instructions, when the computer readable instructions are executed by one or more processors, such that the one or Multiple processors perform the following steps:

User A sends the first encrypted information to User B;

User B receives the first encrypted information, and obtains a first random number after decryption;

User B sends second encrypted information to user A;

User A receives the second encrypted information, and obtains a second random number after decryption;

User A and user B perform a key generation algorithm based on the first random number and the second random number to obtain a key Key and an initialization variable IV;

User A and user B perform encrypted communication using the CBC mode of the AES algorithm based on the key Key and the initialization variable IV.

In the method, device, terminal device and storage medium for user communication encryption on the blockchain provided by the embodiment of the present application, user A first sends the first encrypted information to user B, and user B receives the first encrypted information, and obtains the first after decryption. a random number; user B sends the second encrypted information to user A, user A receives the second encrypted information, and obtains the second random number after decryption, and user A and user B acquire the first random number sent by the other party by using the encryption and decryption random number The number and the second random number provide the basis for subsequent encrypted communication. Then, user A and user B execute a key generation algorithm based on the first random number and the second random number to obtain a key Key and an initialization variable IV, and the generated key Key and initialization variable IV are jointly obtained by user A and user B. The key Key and the initialization variable IV are obtained by a hash algorithm, have the characteristics of irreversible data, and have high security, and provide a necessary basis for realizing communication encryption between the user A and the user B. Finally, user A and user B perform encrypted communication using the CBC mode of the AES algorithm based on the key Key and the initialization variable IV, so that the third party (users on the blockchain other than user A and user B) has no key Key and initialization. In the case of the variable IV, the communication contents of the user A and the user B cannot be acquired, and the communication content is secure when any two users on the blockchain perform point-to-point communication.

DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings used in the description of the embodiments of the present application will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the present application. Other drawings may also be obtained from those of ordinary skill in the art based on these drawings without the inventive labor.

1 is a flow chart of a method for encrypting user communication on a blockchain in Embodiment 1 of the present application.

FIG. 2 is a specific flow chart of step S10 of FIG. 1.

FIG. 3 is a specific flow chart of step S20 of FIG. 2.

4 is a specific flow chart of step S30 of FIG. 1.

FIG. 5 is a specific flowchart of step S40 in FIG. 1.

Figure 6 is a specific flow chart before step S10 of Figure 1.

FIG. 7 is a specific flowchart of step S60 in FIG. 1.

FIG. 8 is a schematic block diagram of a user communication encryption apparatus on a blockchain in Embodiment 2 of the present application.

FIG. 9 is a schematic diagram of a terminal device in Embodiment 4 of the present application.

detailed description

The technical solutions in the embodiments of the present application are clearly and completely described in the following with reference to the drawings in the embodiments of the present application. It is obvious that the described embodiments are a part of the embodiments of the present application, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present application without departing from the inventive scope are the scope of the present application.

Example 1

FIG. 1 is a flow chart showing a method of encrypting user communication on a blockchain in this embodiment. The user communication encryption method on the blockchain can be applied to an application system based on a blockchain technology, and is used for encrypting communication content when a user performs peer-to-peer communication on a blockchain system, thereby realizing users on the blockchain system. Communication encryption function. As shown in FIG. 1, the user communication encryption method on the blockchain includes the following steps:

S10: User A sends the first encrypted information to User B.

User A and user B refer to any two users on the blockchain system. The user on the blockchain in this embodiment should be understood as each user node on the blockchain system, that is, each related terminal on the blockchain system. The terminal may be a terminal such as a mobile phone, a tablet, and a computer connected through a blockchain network. The first encrypted information refers to information that the user A sent to the user B after being encrypted. The first encrypted information includes the encrypted first random number generated by the user A. The first random number refers to a random number generated by the user A for performing key negotiation with the user B.

Blockchain is a new application model for computer technologies such as distributed data storage, consensus mechanisms, and encryption algorithms. The blockchain system is essentially a decentralized distributed database system. In this embodiment, the communication process between the user A and the user B is performed on the blockchain, and the user A sends the first encrypted information to the user B under the blockchain system, so that the subsequent user B can receive the first Encrypting the information and decrypting the first encrypted information to obtain a first random number.

S20: User B receives the first encrypted information, and obtains the first random number after decryption.

In this embodiment, the user B reads the first encrypted information sent by the user A on the blockchain system, and decrypts the first encrypted information to obtain the first random number. The user B obtains the basis of the key key and the initialization variable IV generated by the user A and the user B jointly negotiated based on the first random number by acquiring the first random number sent by the user A.

S30: User B sends the second encrypted information to User A.

The second encrypted information refers to the information sent by the user B to the user A after the encryption process, and the second encrypted information includes the encrypted second random number generated by the user B. The second random number refers to a random number generated by the user B for performing key negotiation with the user A. The user B sends the second encrypted information to the user A under the blockchain system, so that the subsequent user A receives the second encrypted information, and decrypts the second encrypted information to obtain a second random number.

S40: User A receives the second encrypted information, and obtains the second random number after decryption.

In this embodiment, the user A reads the second encrypted information sent by the user B on the blockchain system, and decrypts the second encrypted information to obtain a second random number. The user A provides a basis for the subsequent generation of the key Key and the initialization variable IV jointly generated by the user A and the user B based on the second random number by acquiring the second random number sent by the user B.

S50: User A and User B execute a key generation algorithm based on the first random number and the second random number to obtain a key Key and an initialization variable IV.

In this embodiment, after user B acquires the first random number generated and sent by user A and user A obtains the second random number generated and sent by user B, user A and user B are based on the first random number and the second random number. At the same time, the key generation algorithm is executed, and according to the key generation algorithm, the key Key and the initialization variable IV are simultaneously acquired (the key Key and the initialization variable IV are basic conditions required for the subsequent user to encrypt and encrypt the process on the blockchain system). By using the first random number and the second random number known only to the user A and the user B on the blockchain system, combined with the key generation algorithm, a key Key and an initialization variable which are safe and reliable and only owned by the user A and the user B are generated. IV.

S60: User A and User B perform encrypted communication using the CBC mode of the AES algorithm based on the key Key and the initialization variable IV.

Among them, the AES algorithm is a symmetric block cipher system, which adopts a replacement/replacement network, and each round consists of a linear mixed layer, a nonlinear layer and a key encryption layer. Among them, the linear mixed layer is used to ensure high spread over multiple rounds, the nonlinear layer is composed of 16 S boxes and plays a role of confusion, and the key encryption layer is used to XOR the subkeys to the intermediate state. AES is an iterative block cipher whose packet length and key length are both variable, except that the packet size for processing is limited to 128 bits in order to meet the requirements of AES, and the key length is 128 bits, 192 bits or 256 bits. The corresponding number of iterations N is 10 rounds, 12 rounds and 14 rounds. AES brings together the benefits of security, efficiency, achievability and flexibility. The biggest advantage is that it can give the probability of the best scoring feature of the algorithm, and analyze the ability of the algorithm to resist cryptanalysis and linear cryptanalysis. The CBC mode is a packet encryption mode. For each cipher block to be encrypted, it is XORed with the ciphertext of the previous cipher block before encryption (in particular, the first plaintext block and a data block called the initialization vector IV). XOR), then encrypt it with a cipher. The AES-CBC mode uses the encryption and decryption mode as CBC, and the algorithm uses the AES algorithm to encrypt and decrypt.

In this embodiment, user A and user B are securely and reliably obtained based on mutual agreement and only the key Key and initialization variable IV owned by user A and user B are used, and the user is on the blockchain by adopting the AES algorithm and adopting the CBC mode. Encrypted communication.

In this embodiment, combined with the nature and characteristics of the blockchain system itself, through a series of associated encryption operations, layers are layered to improve security, ensuring the security of user communication on the blockchain system. First, user A sends the first encrypted information to user B, user B receives the first encrypted information, and obtains the first random number after decryption; user B sends the second encrypted information to user A, and user A receives the second encrypted information, and obtains the second encrypted information. The second random number, the user A and the user B acquire the first random number and the second random number sent by the other party by using the encryption and decryption random number, which provides a basis for the subsequent encrypted communication. Then, user A and user B execute a key generation algorithm based on the first random number and the second random number to obtain a key Key and an initialization variable IV, and the generated key Key and initialization variable IV are jointly obtained by user A and user B. The key Key and the initialization variable IV are obtained by a hash algorithm, have the characteristics of irreversible data, and have high security, and provide a necessary basis for realizing communication encryption between the user A and the user B. Finally, user A and user B perform encrypted communication using the CBC mode of the AES algorithm based on the key Key and the initialization variable IV, so that the third party (users on the blockchain other than user A and user B) has no key Key and initialization. In the case of the variable IV, the communication contents of the user A and the user B cannot be acquired, and the communication content is secure when any two users on the blockchain perform point-to-point communication.

In a specific implementation, as shown in FIG. 2, in step S10, the user A sends the first encryption information to the user B, which specifically includes the following steps:

S11: User A obtains the second public key from the user certificate of user B.

The user certificate is a certificate issued by each system for verifying the identity of the user by the system root certificate on the blockchain. Each user on the blockchain has a unique user certificate. The root certificate of the system is customized on the blockchain. Specifically, the system administrator on the blockchain can create a unique key-value pair. The key of the key-value pair is Key=ROOT, value=cert, cert The system root certificate. The system root certificate includes a pair of corresponding public and private keys (ie, a pair of keys). The public key is used for user authentication, and the private key is used to encrypt the original user certificate (that is, the digital certificate has not been digitally signed by the system root certificate). User certificate). The system root certificate generates a pair of key pairs for the user certificate when the user certificate is issued to each user on the blockchain, so that any two users on the blockchain can perform peer-to-peer communication based on their corresponding users. The certificate is authenticated. User authentication performed on the blockchain system does not need to be implemented by an external third-party certificate issuing authority, which improves the reliability of authentication between users of the blockchain system.

In this embodiment, user A communicates with user B through the blockchain system, and both parties need to perform user authentication before continuing communication. For example, user B needs to verify whether user A is a legitimate user on the blockchain system, and user B will The system root certificate on the blockchain system is read, and the user certificate of the user A is decrypted and verified by using the public key of the system root certificate. If the decryption result includes the digital signature of the system root certificate, the user A is considered to be on the blockchain system. Legal user. After verifying the identity of the identity, the user A will obtain the second public key in the user certificate of the user B, so as to subsequently encrypt the first random number generated by the user A by using the second public key. The second public key is a public key stored in the user certificate of the user B.

S12: User A generates a first random number, and encrypts the first random number by using a second public key to obtain first encrypted information.

In this embodiment, the user A generates a first random number on the blockchain, and encrypts the first random number by using the second public key in the user certificate of the user B to obtain the first encrypted information. It can be understood that before the first random number is encrypted, a prefix of “key negotiation 1” may be added before the first random number to indicate or distinguish the use of the first random number to be encrypted by the prefix. Therefore, after decrypting the first encrypted information, the user B can learn, according to the prefix, that the decrypted first random number is a random number for performing key negotiation between the user A and the user B.

S13: User A sends the first encrypted information to User B through the blockchain system.

In this embodiment, in combination with the nature of the blockchain itself, the user A on the blockchain can send the first encrypted information to the user B through the blockchain system. Specifically, it can be implemented in the following two ways:

In the first communication mode, the user's communication address is set on the blockchain to implement user communication on the blockchain based on the communication. The user's communication address can be specifically the user's email address. In this embodiment, the email addresses of user A and user B are first set, for example, the email address of user A is represented as MailuserAAA. User A and User B's email addresses are created in a key-value pair, and the email address is the key in the key-value pair. The value corresponding to the email address of user A is Ma, and the value corresponding to the email address of user B is Mb. When sending data, user A reads the email address of user B, obtains the value Mb according to the email address, and adds a key Kab to the value Mb (the value corresponding to the key Kab is Data1), that is, the process of sending the data Data1 is completed. In order to enable the subsequent user B to obtain the newly added key Kab in the corresponding value Mb through its own communication address, the corresponding value Data1 is obtained according to the key Kab, which is the first encrypted information in this embodiment.

In the second communication mode, the user addresses of user A and user B are set on the blockchain system. For example, the user address of user A can be represented as userAAA, and user A creates a key-value pair on the blockchain, and the key-value pair The key is Kab (the same as the kab name of the first method described above, and the specific content is different), and the value is Data1 (this Data1 is the first encrypted information in this embodiment). The key Kab is set to a specific form Kab = data prefix + user address of user B + user address of user A, wherein the data prefix is an identifier used to distinguish data. By setting the key kab to this specific form, the key is created as a kab on the blockchain system, and the corresponding value is the key-value pair of Data1, that is, the process of sending data is completed, so that the subsequent user B passes the query field as " The fuzzy query of the data prefix + user B's user address obtains all the keys starting with the data prefix + user B's user address, thereby obtaining the key Kab, and obtaining the value Data1 by the key Kab.

In a specific implementation, as shown in FIG. 3, in step S20, the user B receives the first encrypted information, and obtains the first random number after decryption, which specifically includes the following steps:

S21: User B receives the first encrypted information sent by user A through the blockchain system.

In this embodiment, the user B receives the first encrypted information sent by the user A according to the nature and characteristics of the blockchain system through the blockchain system. Specifically, if the two types of users listed in step S13 communicate on the blockchain, if the first communication mode is adopted, the user B receives the information sent by the user A by reading the email address of the user. Obtaining the corresponding value Mb according to the email address (the email address is a key), and then obtaining the key Kab added by the user A to the value Mb from the value Mb, and then according to the relationship between the key Kab and the value Data1 being a key value pair, The value Data1 is obtained directly from the key Kab. In the present embodiment, the value Data1 is the first encrypted information that the user A wants to send to the user B. If the second communication method in step S13 is adopted, according to the specific form of the key Kab=data prefix+user B user address+user A user address, user B will query by fuzzy query on the blockchain system. The field "data prefix + user address of user B" obtains all the information of the field "data prefix + user address of user B", wherein the obtained information includes the key Kab, and finally the corresponding value Data1 is obtained according to the key Kab. That is, the first encrypted information sent by the user A is obtained. Based on the nature and characteristics of the blockchain system, the user B can receive the first encrypted information sent by the user A through the blockchain system.

S22: The user B decrypts the first encrypted information by using a second private key corresponding to the second public key to obtain the first random number.

After the user B obtains the first encrypted information sent by the user A, the first encrypted information is obtained by using the public key of the user certificate of the user B (that is, the second public key in this embodiment), so that the first decryption is performed. The encrypted information requires the private key of the user certificate of User B (ie, the second private key in this embodiment). In this embodiment, the user B decrypts the first encrypted information by using the second private key corresponding to the second public key, and obtains the first random number generated by the user A after decryption.

In this embodiment, by using the system root certificate customized in the blockchain, the system root certificate is used to generate the user certificate of the user on the blockchain, and the key pair (public key and private key) of the user certificate is implemented. The random number exchanged by the user-generated random number on the blockchain is used to encrypt and send the random number exchange process, and the user exchanges the random number on the blockchain system, which provides a basis for generating the key Key and the initialization variable IV according to the random number.

In a specific implementation, as shown in FIG. 4, in step S30, the user B sends the second encryption information to the user A, which specifically includes the following steps:

S31: User B obtains the first public key from the user certificate of user A.

Similar to step S11, refer to the implementation process of step S11, and details are not described herein again.

S32: User B generates a second random number, and encrypts the second random number by using the first public key to obtain second encrypted information.

Similar to step S12, refer to the implementation process of step S11, and details are not described herein again.

S33: User B sends the second encrypted information to user A through the blockchain system.

Similar to step S13, refer to the implementation process of step S11, and details are not described herein again.

In a specific implementation, as shown in FIG. 5, in step S40, user A receives the second encrypted information, and obtains the second random number after decryption, which specifically includes the following steps:

S41: User A receives the second encrypted information sent by user B through the blockchain system.

Similar to step S21, refer to the implementation process of step S21, and details are not described herein again.

S42: User A decrypts the second encrypted information by using the first private key corresponding to the first public key to obtain a second random number.

Similar to step S22, refer to the implementation process of step S22, and details are not described herein again.

In a specific embodiment, as shown in FIG. 6, before the step S10, that is, before the user A sends the first encrypted information to the user B, the user communication encryption method on the blockchain further includes the following steps:

S101: User A and User B query their respective local databases in advance.

The blockchain system is essentially a decentralized distributed database system. In this embodiment, before any two users (ie, user A and user B) on the blockchain system communicate, the respective local databases are queried in advance. As can be appreciated, the purpose of this step is to query the local database prior to communication to determine if there is an existing, directly available key Key and initialization variable IV.

S102: If the key Key and the initialization variable IV exist in the local database, check the creation time of the key Key and the initialization variable IV.

In this embodiment, if the key Key and the initialization variable IV required for the communication process already exist in the local database, the creation time of the key Key and the initialization variable IV needs to be checked to determine the key Key and the initialization variable IV. Can it be used?

S103: If the creation time does not exceed the preset valid time, the existing key Key and the initialization variable IV are used, and the CBC mode of the AES algorithm is used for the encrypted communication.

The preset effective time refers to a valid time period of the preset key key and the initialization variable IV. In this embodiment, if the creation time of the key Key and the initialization variable IV does not exceed the preset effective time, the key Key and the initialization variable IV that have been saved in the local database may be used, and the CBC mode of the AES algorithm is used. Encrypted communication ensures the security of communication on the blockchain system.

In a specific implementation, in step S50, the key generation algorithm is specifically:

C(0)=Hash(random1)

C(n)=HMAC _C(n-1) (Hash(random2))

Key=HMAC _{Hash(random1||random2)} (C0+C1)

IV=HMAC _{Hash(random1||random2)} (C0+C2)

Where random1 represents the first random number, random2 represents the second random number, n is a positive integer greater than 0, Hash represents a hash function, the algorithm uses the SHA256 algorithm, and HMAC refers to the key-related hash operation, the algorithm uses SHA256 Algorithm, || indicates the connection operation.

In this embodiment, the user A and the user B simultaneously execute the key generation algorithm of generating the key Key and the initialization variable IV, and the first random number and the second random number are known only by the user A and the user B, and the blockchain system is improved. The security of communication. The algorithm combines the characteristics of the first random number and the second random number, and uses a hash algorithm (ie, Hash algorithm) to generate multiple information digests (such as C0, C1, and C2), according to the first random number, the second random number, and the generated. Summary of information (such as C0, C1, and C2), through the hash algorithm (also known as one-way hash algorithm) to generate the acquisition key Key and initialization variable IV, for subsequent block based on the key Key and initialization variable IV User communication encryption on the chain system provides a solid foundation for improving the security of user communications on the blockchain system.

It should be noted that the SHA256 algorithm is one of the hash algorithms, and is different from the AES algorithm in this embodiment. The SHA256 algorithm is required to generate the key Key and the initialization variable IV, and the AES algorithm is required for user communication encryption.

In a specific implementation, as shown in FIG. 7, in step S60, user A and user B perform encrypted communication using the CBC mode of the AES algorithm based on the key Key and the initialization variable IV, and specifically include the following steps:

S61: User A writes data K:V to the blockchain in a key-value pair, where K represents a key and V represents a value.

S62: User A encrypts K based on the key Key and initialization variable IV in the CBC mode of the AES algorithm, and obtains KC, KC=AES_CBC(K).

S63: User A encrypts V by using CBC mode of AES algorithm based on key Key and initialization variable IV, and obtains VC, VC=AES_CBC(V).

S64: User A writes the data {KC:VC+IV} to the blockchain.

S65: User B reads KC on the blockchain, and obtains VC and initialization variable IV according to KC.

S66: User B decrypts KC by using CBC mode of AES algorithm based on key Key and initialization variable IV, and obtains K, K=AES_CBC(KC).

S67: User B decrypts the VC by using the CBC mode of the AES algorithm based on the key Key and the initialization variable IV, and obtains V, V=AES_CBC (VC).

S68: User B obtains data K:V.

In this embodiment, steps S61-S64 are processes in which the user A encrypts the communication content using the CBC mode of the AES algorithm based on the key Key and the initialization variable IV. Accordingly, steps S65-S68 are processes in which the user B decrypts the communication content using the CBC mode of the AES algorithm based on the key Key and the initialization variable IV. Any user on the blockchain (such as user A) can write the data to be encrypted and communicated to the blockchain through steps S61-S64, so that only the user who owns the key Key and the initialization variable IV (such as the user) The user B) of the A communication can decrypt the encrypted data on the read blockchain. The communication content, that is, the communication data is stored in a key value pair. The CBC mode of the AES algorithm encrypts the data stored in the key value pair mode, and the key Key and the initialization variable IV are well adopted, so that The user communication encryption process on the blockchain is more secure and reliable.

In the method for encrypting user communication on the blockchain provided in this embodiment, first, user A sends the first encrypted information to user B, and user B receives the first encrypted information, and obtains the first random number after decryption; user B sends the message to user A. The second encrypted information is obtained by the user A, and the second random number is obtained after the decryption is performed. The user A and the user B obtain the first random number and the second random number sent by the other party by using the encryption and decryption random number. The key Key and the initialization variable IV are generated based on the first random number and the second random number, and provide a basis for encrypted communication according to the key Key and the initialization variable IV. Then user A and user B execute a key generation algorithm based on the first random number and the second random number to obtain a key Key and an initialization variable IV, and the generated key Key and initialization variable IV are user A and user B passing the first random The number and the second random number are jointly negotiated, and the key Key and the initialization variable IV are obtained by a hash algorithm, and have the characteristics of irreversible data, high security, and provide for encrypting communication between user A and user B. The necessary foundation. Finally, user A and user B perform encrypted communication using the CBC mode of the AES algorithm based on the key Key and the initialization variable IV, so that the third party (users on the blockchain other than user A and user B) has no key Key and initialization. In the case of the variable IV, the communication contents of the user A and the user B cannot be acquired, and the communication content is secure when any two users on the blockchain perform point-to-point communication.

The user communication encryption method on the blockchain provided by this embodiment further combines the nature and characteristics of the blockchain, and sets a system root certificate on the blockchain system; implements and performs any two users on the blockchain system. Point-to-point communication, that is, by virtualizing a communication channel on the blockchain system, data communication between any two users on the blockchain is realized. Users only need to maintain communication with the blockchain network to realize data sharing storage and data communication between all users, which can effectively simplify the construction of application systems, reduce system complexity, and enhance the security of blockchain systems. Robustness. By means of the nature and characteristics of the blockchain system itself, the communication process of users on the blockchain system is under a unified system, and the blockchain is further ensured without the help of other third-party systems, certification bodies and tools. User communication security.

It should be understood that the size of the sequence of the steps in the above embodiments does not mean that the order of execution is performed. The order of execution of each process should be determined by its function and internal logic, and should not be construed as limiting the implementation process of the embodiments of the present application.

Example 2

Fig. 8 is a block diagram showing the principle of the user communication encryption device on the block chain corresponding to the user communication encryption method on the blockchain in the first embodiment. As shown in FIG. 8, the user communication encryption device on the blockchain includes a first encrypted information sending module 10, a first random number obtaining module 20, a second encrypted information sending module 30, a second random number obtaining module 40, and a key. And the initialization variable acquisition module 50 and the encryption communication module 60. The first encryption information sending module 10, the first random number obtaining module 20, the second encrypted information sending module 30, the second random number obtaining module 40, the key and initialization variable obtaining module 50, and the encryption communication module 60 are implemented. The steps corresponding to the user communication encryption method on the blockchain in the first embodiment are in one-to-one correspondence. To avoid redundancy, the present embodiment will not be described in detail.

The first encrypted information sending module 10 is configured to send the first encrypted information to the user B by the user A.

The first random number obtaining module 20 is configured to receive the first encrypted information by the user B, and obtain the first random number after decryption.

The second encrypted information sending module 30 is configured to send the second encrypted information to the user A by the user B.

The second random number obtaining module 40 is configured to receive the second encrypted information by the user A, and obtain the second random number after decryption.

The key and initialization variable obtaining module 50 is configured to perform a key generation algorithm based on the first random number and the second random number by the user A and the user B, and acquire the key Key and the initialization variable IV.

The encrypted communication module 60 is configured for the user A and the user B to perform encrypted communication using the CBC mode of the AES algorithm based on the key Key and the initialization variable IV.

Preferably, the first encrypted information transmitting module 10 includes a second public key obtaining unit 11, a first encrypted information acquiring unit 12, and a first encrypted information transmitting unit 13.

The second public key obtaining unit 11 is configured to obtain the second public key from the user certificate of the user B.

The first encryption information acquiring unit 12 is configured to generate a first random number by the user A, and encrypt the first random number by using the second public key to obtain the first encrypted information.

The first encrypted information transmitting unit 13 is configured to send the first encrypted information to the user B through the blockchain.

Preferably, the first random number obtaining module 20 includes a first encrypted information receiving unit 21 and a first random number obtaining unit 22.

The first encryption information receiving unit 21 is configured to receive, by the user B, the first encrypted information sent by the user A through the blockchain system.

The first random number obtaining unit 22 is configured to: the user B decrypts the first encrypted information by using a second private key corresponding to the second public key, and acquires the first random number.

Preferably, the second encrypted information transmitting module 30 includes a first public key obtaining unit 31, a second encrypted information acquiring unit 32, and a second encrypted information transmitting unit 33.

The first public key obtaining unit 31 is configured to obtain the first public key from the user certificate of the user A.

The second encryption information acquiring unit 32 is configured to generate a second random number by the user B, and encrypt the second random number by using the first public key to obtain the second encrypted information.

The second encrypted information transmitting unit 33 is configured to send the second encrypted information to the user A through the blockchain.

Preferably, the second random number obtaining module 40 includes a second encrypted information receiving unit 41 and a second random number obtaining unit 42.

The second encrypted information receiving unit 41 is configured to receive, by the user A, the second encrypted information sent by the user B through the blockchain system.

The second random number obtaining unit 42 is configured to: the user A decrypts the second encrypted information by using the first private key corresponding to the first public key, and acquires the second random number.

Preferably, the user chain encryption device on the blockchain further includes a pre-query module 70, which includes a query unit 71, a creation time viewing unit 72, and a determination employing unit 73.

The query unit 71 is configured for the user A and the user B to query the respective local databases in advance.

The creation time viewing unit 72 is configured to view the creation time of the key Key and the initialization variable IV if the key Key and the initialization variable IV exist in the local database.

The determining unit 73 is configured to perform the encrypted communication by using the CBC mode of the AES algorithm by using the existing key Key and the initialization variable IV if the creation time does not exceed the preset effective time.

Preferably, the key generation algorithm is:

C(0)=Hash(random1)

C(n)=HMAC _C(n-1) (Hash(random2))

Key=HMAC _{Hash(random1||random2)} (C0+C1)

IV=HMAC _{Hash(random1||random2)} (C0+C2)

Where random1 represents the first random number, random2 represents the second random number, n is a positive integer greater than 0, Hash represents a hash function, the algorithm uses the SHA256 algorithm, and HMAC refers to the key-related hash operation, the algorithm uses SHA256 Algorithm, || indicates the connection operation.

Preferably, the encrypted communication module 60 includes a data writing unit 61, a key encrypting unit 62, a value encrypting unit 63, an encrypted data writing unit 64, an encrypted data reading unit 65, a key decrypting unit 66, a value decrypting unit 67, and data acquisition. Unit 68.

The data writing unit 61 is for the user A to write the data K:V to the blockchain in a key-value pair, where K represents a key and V represents a value.

The key encryption unit 62 is configured to encrypt K by the user A based on the key Key and the initialization variable IV in the CBC mode of the AES algorithm, and acquire KC, KC=AES_CBC(K).

The value encryption unit 63 is configured to encrypt the V by the user A based on the key Key and the initialization variable IV in the CBC mode of the AES algorithm, and obtain VC, VC=AES_CBC(V).

Encrypted data is written to unit 64 for user A to write data {KC:VC+IV} onto the blockchain.

The encrypted data reading unit 65 is configured for the user B to read the KC on the blockchain, and acquire the VC and the initialization variable IV according to the KC.

The key decryption unit 66 is configured to decrypt the KC by the user B using the CBC mode of the AES algorithm based on the key Key and the initialization variable IV, and obtain K, K=AES_CBC (KC).

The value decryption unit 67 is configured to decrypt the VC by using the CBC mode of the AES algorithm based on the key Key and the initialization variable IV, and obtain V, V=AES_CBC (VC).

The data acquisition unit 68 is configured for the user B to acquire the data K:V.

In the user link encryption device on the blockchain provided by this embodiment, the first encrypted information sending module 10, the first random number obtaining module 20, the second encrypted information sending module 30, and the second random number obtaining module 40, the user A And the user B acquires the first random number and the second random number sent by the other party by using the encryption and decryption random number, and generates a key Key and an initialization variable IV according to the first random number and the second random number, and according to the secret The encrypted communication of the key Key and the initialization variable IV provides the basis. The key and initialization variable obtaining module 50, the generated key Key and the initialization variable IV are obtained by the user A and the user B jointly negotiated by the first random number and the second random number, and the key key and the initialization variable IV are passed through The algorithm is acquired, has the characteristics of irreversible data, and has high security, which provides a necessary basis for realizing communication encryption between user A and user B. The communication module 60 is encrypted so that the third party (users on the block chain other than the user A and the user B) cannot obtain the communication contents of the user A and the user B without the key Key and the initialization variable IV, and the area is secured. The security of the communication content when any two users on the blockchain perform point-to-point communication.

Example 3

The embodiment provides one or more non-volatile readable storage media having computer readable instructions that, when executed by one or more processors, cause the one or more processors to execute The user communication encryption method on the blockchain in Embodiment 1 is implemented. To avoid repetition, details are not described herein again. Alternatively, when the computer readable instructions are executed by one or more processors, causing the one or more processors to perform the functions of the modules/units in the user communication encryption device on the blockchain in Embodiment 2, To avoid repetition, we will not repeat them here.

Example 4

Figure 9 is a schematic diagram of a terminal device in this embodiment. As shown in FIG. 9, terminal device 80 includes a processor 81, a memory 82, and computer readable instructions 83 stored in memory 82 and operative on processor 81. The processor 81 implements the various steps of the user communication encryption method on the blockchain in Embodiment 1 when the computer readable instructions 83 are executed, such as steps S10, S20, S30, S40, S50, and S60 shown in FIG. Alternatively, when the processor 81 executes the computer readable instructions 83, the functions of the modules/units of the user communication encryption device on the blockchain in Embodiment 2 are implemented. As shown in FIG. 8, the first encrypted information sending module 10 obtains the first random number. The functions of the module 20, the second encrypted information transmitting module 30, the second random number obtaining module 40, the key and initialization variable obtaining module 50, and the encrypted communication module 60.

Illustratively, computer readable instructions 83 may be partitioned into one or more modules/units, one or more modules/units being stored in memory 82 and executed by processor 81 to complete the application. The one or more modules/units may be an instruction segment of a series of computer readable instructions 83 capable of performing a particular function for describing the execution of computer readable instructions 83 in the terminal device 80. For example, the computer readable instructions 83 may be divided into the first encrypted information transmitting module 10, the first random number obtaining module 20, the second encrypted information transmitting module 30, the second random number obtaining module 40, and the key in Embodiment 2. And the initialization variable acquisition module 50 and the encryption communication module 60, the specific functions of each module are as shown in the embodiment 2, in order to avoid repetition, not repeated here.

The terminal device 80 can be a computing device such as a desktop computer, a notebook, a palmtop computer, and a cloud server. The terminal device may include, but is not limited to, a processor 81, a memory 82. It will be understood by those skilled in the art that FIG. 9 is merely an example of the terminal device 80 and does not constitute a limitation of the terminal device 80, and may include more or less components than those illustrated, or may combine certain components or different components. For example, the terminal device may further include an input/output device, a network access device, a bus, and the like.

The processor 81 may be a central processing unit (CPU), or may be other general-purpose processors, a digital signal processor (DSP), an application specific integrated circuit (ASIC), Field-Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware components, etc. The general purpose processor may be a microprocessor or the processor or any conventional processor or the like.

The memory 82 may be an internal storage unit of the terminal device 80, such as a hard disk or a memory of the terminal device 80. The memory 82 may also be an external storage device of the terminal device 80, such as a plug-in hard disk provided on the terminal device 80, a smart memory card (SMC), a Secure Digital (SD) card, and a flash memory card (Flash). Card) and so on. Further, the memory 82 may also include both an internal storage unit of the terminal device 80 and an external storage device. The memory 82 is used to store computer readable instructions 83 and other programs and data required by the terminal device. The memory 82 can also be used to temporarily store data that has been output or is about to be output.

It will be apparent to those skilled in the art that, for convenience and brevity of description, only the division of each functional unit and module described above is exemplified. In practical applications, the above functions may be assigned to different functional units as needed. The module is completed by dividing the internal structure of the device into different functional units or modules to perform all or part of the functions described above.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

The integrated modules/units, if implemented in the form of software functional units and sold or used as separate products, may be stored in a computer readable storage medium. Based on such understanding, the present application implements all or part of the processes in the above embodiments, and may also be completed by computer readable instructions 83, which may be stored in a computer readable storage. In the medium, the computer readable instructions 83, when executed by the processor, may implement the steps of the various method embodiments described above. Wherein, the computer readable instructions 83 comprise code of computer readable instructions, the code of which may be in the form of source code, in the form of an object code, an executable file or some intermediate form or the like. The computer readable medium can include any entity or device capable of carrying the code of the computer readable instructions, a recording medium, a USB flash drive, a removable hard drive, a magnetic disk, an optical disk, a computer memory, a read only memory (ROM, Read- Only Memory), Random Access Memory (RAM), electrical carrier signals, telecommunications signals, and software distribution media. It should be noted that the content contained in the computer readable medium may be appropriately increased or decreased according to the requirements of legislation and patent practice in a jurisdiction, for example, in some jurisdictions, according to legislation and patent practice, computer readable media It does not include electrical carrier signals and telecommunication signals.

The above-mentioned embodiments are only used to explain the technical solutions of the present application, and are not limited thereto; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still implement the foregoing embodiments. The technical solutions described in the examples are modified or equivalently replaced with some of the technical features; and the modifications or substitutions do not deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in Within the scope of protection of this application.

Claims (20)

1. A method for encrypting user communication on a blockchain, characterized in that it comprises:

   User A sends the first encrypted information to User B;

   User B receives the first encrypted information, and obtains a first random number after decryption;

   User B sends second encrypted information to user A;

   User A receives the second encrypted information, and obtains a second random number after decryption;

   User A and user B perform a key generation algorithm based on the first random number and the second random number to obtain a key Key and an initialization variable IV;

   User A and user B perform encrypted communication using the CBC mode of the AES algorithm based on the key Key and the initialization variable IV.
2. The method for encrypting user communication on a blockchain according to claim 1, wherein the user A sends the first encrypted information to the user B, including:

   User A obtains the second public key from the user certificate of user B.

   User A generates a first random number, and encrypts the first random number by using the second public key to obtain the first encrypted information.

   User A sends the first encrypted information to user B through a blockchain system;

   The user B sends the second encrypted information to the user A, including:

   User B obtains the first public key from the user certificate of user A;

   The user B generates a second random number, and encrypts the second random number by using the first public key to obtain the second encrypted information.

   User B sends the second encrypted information to User A through the blockchain system.
3. The method for encrypting user communication on a blockchain according to claim 2, wherein the user B receives the first encrypted information, and obtains a first random number after decryption, including:

   User B receives the first encrypted information sent by user A through a blockchain system;

   The user B decrypts the first encrypted information by using a second private key corresponding to the second public key, and acquires the first random number;

   The user A receives the second encrypted information, and obtains a second random number after decryption, including:

   User A receives the second encrypted information sent by user B through a blockchain system;

   The user A decrypts the second encrypted information by using a first private key corresponding to the first public key, and acquires the second random number.
4. The method for encrypting user communication on the blockchain according to claim 1, wherein before the step of the user A transmitting the first encrypted information to the user B, the method for encrypting the user communication on the blockchain further comprises:

   User A and User B pre-query their respective local databases;

   If the key Key and the initialization variable IV are present in the local database, view the creation time of the key Key and the initialization variable IV;

   If the creation time does not exceed the preset valid time, the existing key Key and the initialization variable IV are used, and the CBC mode of the AES algorithm is used for encrypted communication.
5. The method for encrypting user communication on a blockchain according to claim 1, wherein the key generation algorithm is:

   C(0)=Hash(random1)

   C(n)=HMAC _C(n-1) (Hash(random2))

   Key=HMAC _{Hash(random1||random2)} (C0+C1)

   IV=HMAC _{Hash(random1||random2)} (C0+C2)

   Where random1 represents the first random number, random2 represents the second random number, n is a positive integer greater than 0, Hash represents a hash function, the algorithm uses the SHA256 algorithm, and HMAC refers to the key-related hash operation, the algorithm uses SHA256 Algorithm, || indicates the connection operation.
6. The method for encrypting user communication on a blockchain according to claim 1, wherein the user A and the user B perform communication encryption using the CBC mode of the AES algorithm based on the key Key and the initialization variable IV. include:

   User A writes the data K:V to the blockchain in a key-value pair, where K represents the key and V represents the value;

   User A encrypts K based on the key Key and the initialization variable IV using the CBC mode of the AES algorithm to obtain KC, KC=AES_CBC(K);

   User A encrypts V based on the key Key and the initialization variable IV using the CBC mode of the AES algorithm to obtain VC, VC=AES_CBC(V);

   User A writes the data {KC:VC+IV} to the blockchain;

   User B reads the KC on the blockchain, and obtains the VC and the initialization variable IV according to the KC;

   User B decrypts KC based on the key Key and the initialization variable IV using the CBC mode of the AES algorithm to obtain K, K=AES_CBC(KC);

   User B decrypts the VC based on the key Key and the initialization variable IV using the CBC mode of the AES algorithm to obtain V, V=AES_CBC(VC);

   User B obtains the data K:V.
7. A user chain encryption device on a blockchain, comprising:

   a first encryption information sending module, configured for user A to send first encrypted information to user B;

   a first random number obtaining module, configured to receive, by the user B, the first encrypted information, and obtain a first random number after decryption;

   a second encrypted information sending module, configured for user B to send second encrypted information to user A;

   a second random number obtaining module, configured to receive the second encrypted information by the user A, and obtain a second random number after decryption;

   a key and initialization variable obtaining module, configured for user A and user B to perform a key generation algorithm based on the first random number and the second random number, to obtain a key Key and an initialization variable IV;

   The encrypted communication module is used for user A and user B to perform encrypted communication using the CBC mode of the AES algorithm based on the key Key and the initialization variable IV.
8. The device for encrypting a user link on the blockchain according to claim 7, wherein the first encrypted information transmitting module comprises:

   a second public key obtaining unit, configured for user A to obtain a second public key from the user certificate of user B;

   a first encryption information acquiring unit, configured to generate a first random number by the user A, and encrypt the first random number by using the second public key to obtain the first encrypted information;

   a first encryption information sending unit, configured to send, by the user A, the first encrypted information to the user B through the blockchain;

   The second encrypted information sending module includes:

   a first public key obtaining unit, configured for user B to obtain a first public key from a user certificate of user A;

   a second encryption information acquiring unit, configured to generate a second random number by the user B, and encrypt the second random number by using the first public key to obtain the second encrypted information;

   The second encrypted information sending unit is configured to send, by the user B, the second encrypted information to the user A through the blockchain.
9. A terminal device comprising a memory, a processor, and computer readable instructions stored in the memory and operable on the processor, wherein the processor executes the computer readable instructions as follows step:

   User A sends the first encrypted information to User B;

   User B receives the first encrypted information, and obtains a first random number after decryption;

   User B sends second encrypted information to user A;

   User A receives the second encrypted information, and obtains a second random number after decryption;

   User A and user B perform a key generation algorithm based on the first random number and the second random number to obtain a key Key and an initialization variable IV;

   User A and user B perform encrypted communication using the CBC mode of the AES algorithm based on the key Key and the initialization variable IV.
10. The terminal device according to claim 9, wherein the user A sends the first encrypted information to the user B, including:

    User A obtains the second public key from the user certificate of user B.

    User A generates a first random number, and encrypts the first random number by using the second public key to obtain the first encrypted information.

    User A sends the first encrypted information to user B through a blockchain system;

    The user B sends the second encrypted information to the user A, including:

    User B obtains the first public key from the user certificate of user A;

    The user B generates a second random number, and encrypts the second random number by using the first public key to obtain the second encrypted information.

    User B sends the second encrypted information to User A through the blockchain system.
11. The terminal device according to claim 10, wherein the user B receives the first encrypted information, and obtains the first random number after decryption, including:

    User B receives the first encrypted information sent by user A through a blockchain system;

    The user B decrypts the first encrypted information by using a second private key corresponding to the second public key, and acquires the first random number;

    The user A receives the second encrypted information, and obtains a second random number after decryption, including:

    User A receives the second encrypted information sent by user B through a blockchain system;

    The user A decrypts the second encrypted information by using a first private key corresponding to the first public key, and acquires the second random number.
12. The terminal device according to claim 9, wherein before the step of the user A transmitting the first encrypted information to the user B, the method for encrypting the user communication on the blockchain further comprises:

    User A and User B pre-query their respective local databases;

    If the key Key and the initialization variable IV are present in the local database, view the creation time of the key Key and the initialization variable IV;

    If the creation time does not exceed the preset valid time, the existing key Key and the initialization variable IV are used, and the CBC mode of the AES algorithm is used for encrypted communication.
13. The terminal device according to claim 9, wherein the key generation algorithm is:

    C(0)=Hash(random1)

    C(n)=HMAC _C(n-1) (Hash(random2))

    Key=HMAC _{Hash(random1||random2)} (C0+C1)

    IV=HMAC _{Hash(random1||random2)} (C0+C2)

    Where random1 represents the first random number, random2 represents the second random number, n is a positive integer greater than 0, Hash represents a hash function, the algorithm uses the SHA256 algorithm, and HMAC refers to the key-related hash operation, the algorithm uses SHA256 Algorithm, || indicates the connection operation.
14. The terminal device according to claim 9, wherein the user A and the user B perform communication encryption using the CBC mode of the AES algorithm based on the key Key and the initialization variable IV, including:

    User A writes the data K:V to the blockchain in a key-value pair, where K represents the key and V represents the value;

    User A encrypts K based on the key Key and the initialization variable IV using the CBC mode of the AES algorithm to obtain KC, KC=AES_CBC(K);

    User A encrypts V based on the key Key and the initialization variable IV using the CBC mode of the AES algorithm to obtain VC, VC=AES_CBC(V);

    User A writes the data {KC:VC+IV} to the blockchain;

    User B reads the KC on the blockchain, and obtains the VC and the initialization variable IV according to the KC;

    User B decrypts KC based on the key Key and the initialization variable IV using the CBC mode of the AES algorithm to obtain K, K=AES_CBC(KC);

    User B decrypts the VC based on the key Key and the initialization variable IV using the CBC mode of the AES algorithm to obtain V, V=AES_CBC(VC);

    User B obtains the data K:V.
15. One or more non-transitory readable storage mediums storing computer readable instructions, wherein when the computer readable instructions are executed by one or more processors, cause the one or more processors to execute The following steps:

    User A sends the first encrypted information to User B;

    User B receives the first encrypted information, and obtains a first random number after decryption;

    User B sends second encrypted information to user A;

    User A receives the second encrypted information, and obtains a second random number after decryption;

    User A and user B perform a key generation algorithm based on the first random number and the second random number to obtain a key Key and an initialization variable IV;

    User A and user B perform encrypted communication using the CBC mode of the AES algorithm based on the key Key and the initialization variable IV.
16. The non-volatile readable storage medium according to claim 15, wherein the user A sends the first encrypted information to the user B, including:

    User A obtains the second public key from the user certificate of user B.

    User A generates a first random number, and encrypts the first random number by using the second public key to obtain the first encrypted information.

    User A sends the first encrypted information to user B through a blockchain system;

    The user B sends the second encrypted information to the user A, including:

    User B obtains the first public key from the user certificate of user A;

    The user B generates a second random number, and encrypts the second random number by using the first public key to obtain the second encrypted information.

    User B sends the second encrypted information to User A through the blockchain system.
17. The non-volatile readable storage medium according to claim 16, wherein the user B receives the first encrypted information, and obtains the first random number after decryption, including:

    User B receives the first encrypted information sent by user A through a blockchain system;

    The user B decrypts the first encrypted information by using a second private key corresponding to the second public key, and acquires the first random number;

    The user A receives the second encrypted information, and obtains a second random number after decryption, including:

    User A receives the second encrypted information sent by user B through a blockchain system;

    The user A decrypts the second encrypted information by using a first private key corresponding to the first public key, and acquires the second random number.
18. The non-volatile readable storage medium according to claim 15, wherein before the step of the user A transmitting the first encrypted information to the user B, the method for encrypting the user communication on the blockchain further comprises:

    User A and User B pre-query their respective local databases;

    If the key Key and the initialization variable IV are present in the local database, view the creation time of the key Key and the initialization variable IV;

    If the creation time does not exceed the preset valid time, the existing key Key and the initialization variable IV are used, and the CBC mode of the AES algorithm is used for encrypted communication.
19. The non-volatile readable storage medium according to claim 15, wherein the key generation algorithm is:

    C(0)=Hash(random1)

    C(n)=HMAC _C(n-1) (Hash(random2))

    Key=HMAC _{Hash(random1||random2)} (C0+C1)

    IV=HMAC _{Hash(random1||random2)} (C0+C2)

    Where random1 represents the first random number, random2 represents the second random number, n is a positive integer greater than 0, Hash represents a hash function, the algorithm uses the SHA256 algorithm, and HMAC refers to the key-related hash operation, the algorithm uses SHA256 Algorithm, || indicates the connection operation.
20. The non-volatile readable storage medium according to claim 15, wherein the user A and the user B perform communication encryption using the CBC mode of the AES algorithm based on the key Key and the initialization variable IV. include:

    User A writes the data K:V to the blockchain in a key-value pair, where K represents the key and V represents the value;

    User A encrypts K based on the key Key and the initialization variable IV using the CBC mode of the AES algorithm to obtain KC, KC=AES_CBC(K);

    User A encrypts V based on the key Key and the initialization variable IV using the CBC mode of the AES algorithm to obtain VC, VC=AES_CBC(V);

    User A writes the data {KC:VC+IV} to the blockchain;

    User B reads the KC on the blockchain, and obtains the VC and the initialization variable IV according to the KC;

    User B decrypts KC based on the key Key and the initialization variable IV using the CBC mode of the AES algorithm to obtain K, K=AES_CBC(KC);

    User B decrypts the VC based on the key Key and the initialization variable IV using the CBC mode of the AES algorithm to obtain V, V=AES_CBC(VC);

    User B obtains the data K:V.

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