WO2023103099A1

WO2023103099A1 - Control method and system for message storage processing and security authentication, and medium

Info

Publication number: WO2023103099A1
Application number: PCT/CN2021/140521
Authority: WO
Inventors: 陈志祥; 朱明�; 曾祥宇; 丁霞; 王世杰
Original assignee: 天翼物联科技有限公司
Priority date: 2021-12-08
Filing date: 2021-12-22
Publication date: 2023-06-15
Also published as: CN114386054A

Abstract

Disclosed in the present invention are a control method and system for message storage processing and security authentication, and a medium, which can be applied to the technical field of communication security. According to the present invention, an original message is encrypted at a publisher client by using a message key, and is decrypted at a subscriber client by using the message key, such that the original message is in an encrypted state in a transmission process, thereby improving the security of the original message; and a process key is generated at a security authentication center according to the message key, and after a distribution agent obtains the process key from the security authentication center, the process key is used to perform secondary encryption on a first encrypted message, such that the distribution agent cannot infer the message key when only knowing the process key, thereby solving the security problem when the message is processed in a plaintext form at an agent end, and improving the security of the key.

Description

Control method, system and medium for message storage processing and security authentication

technical field

The invention relates to the technical field of communication security, in particular to a control method, system and medium for message storage processing and security authentication.

Background technique

As a lightweight communication protocol, the MQTT protocol has a wide range of applications in today's Internet of Things due to its small communication overhead and adaptability to unreliable networks. In related technologies, in the scheme of data transmission based on the MQTT protocol, the current security scheme for the data transmission process can ensure the security of data in both transmission and storage processing, but the security of the key for encrypting and decrypting messages Sex is not guaranteed.

Contents of the invention

The present invention aims to solve at least one of the technical problems existing in the prior art. Therefore, the present invention proposes a control method, system and medium for message storage processing and security authentication, which can improve the security of keys.

On the one hand, an embodiment of the present invention provides a control method for message storage processing and security authentication, including the following steps:

The security certification center generates a process key according to the message key;

The publisher client uses the message key to encrypt the original message to obtain a first encrypted message, and transmits the first encrypted message to the distribution agent;

The distributed agent obtains the process key from the security authentication center, and uses the process key to encrypt the first encrypted message twice to obtain a second encrypted message;

The subscriber client receives the second encrypted message forwarded by the distribution agent, and uses the message key to decrypt the second encrypted message to obtain an original message.

In some embodiments, a message key of a subject message is generated by the security authentication center, and the message key is managed.

In some embodiments, when encrypting or decrypting the message key according to the exclusive public and private key, the publisher client generates and manages the message key of the topic message on the publisher client, and the security authentication center generates the topic message on the The message key of the subscriber client.

In some embodiments, the message key and the process key are both symmetric keys; the exclusive public and private keys are asymmetric keys.

In some embodiments, the first encrypted message includes a message encrypted with a message key and a message key encrypted with an exclusive public key; the second encrypted message includes a message encrypted with a process key and the subscriber client's message key.

In some embodiments, the distributed agent requests the process key from the security authentication center through the client information and the message key encrypted by the exclusive public key, and the client information includes the subscriber client information and the publisher client information.

In some embodiments, before generating the process key, the security authentication center decrypts the message key encrypted by the exclusive public key sent by the distribution agent with the exclusive private key to obtain the message key of the publisher client, and according to the issued The message key of the subscriber client is randomly generated from the message key of the subscriber client, and the message key of the subscriber client is encrypted with the exclusive private key.

In some embodiments, the subscriber client uses the exclusive public key to decrypt the message key encrypted by the exclusive private key, and uses the decrypted message key to encrypt the process key in the second encrypted message The message is decrypted to get the original message.

On the other hand, an embodiment of the present invention provides a control system for message storage processing and security authentication, including:

Security certification center, used to generate process key according to message key;

The publisher client is configured to use the message key to encrypt the original message to obtain a first encrypted message, and transmit the first encrypted message to the distribution agent;

a distributed agent, configured to obtain the process key from the security certification center, and use the process key to encrypt the first encrypted message twice to obtain a second encrypted message;

The subscriber client is configured to receive the second encrypted message forwarded by the distribution agent, and use the message key to decrypt the second encrypted message to obtain an original message.

On the other hand, an embodiment of the present invention provides a storage medium, in which a computer-executable program is stored, and when the computer-executable program is executed by a processor, it is used to implement the message storage processing and security authentication. control method.

A control method for message storage processing and security authentication provided by an embodiment of the present invention has the following beneficial effects:

In this embodiment, the publisher client uses the message key to encrypt the original message, and the subscriber client uses the message key to decrypt, so that the original message is in an encrypted state during transmission, thereby improving the security of the original message, and , the security authentication center generates the process key according to the message key, and after the distributed agent obtains the process key from the security authentication center, it uses the process key to encrypt the first encrypted message twice, so that the distributed agent only knows the process key When , the message key cannot be deduced, so as to solve the security problem when the message is processed in plain text on the agent side and improve the security of the key.

Additional aspects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Description of drawings

The present invention will be further described below in conjunction with accompanying drawing and embodiment, wherein:

Fig. 1 is a schematic diagram of the positional relationship of the SSL/TLS protocol scheme of an embodiment in the network model;

FIG. 2 is a schematic diagram of interaction between a distribution agent, a security authentication center, a publisher client and a subscriber client according to an embodiment of the present invention;

Fig. 3 is a flowchart of a control method for message storage processing and security authentication according to an embodiment of the present invention.

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals designate the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary only for explaining the present invention and should not be construed as limiting the present invention.

In the description of the present invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc. indicated orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, and are only In order to facilitate the description of the present invention and simplify the description, it does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.

In the description of the present invention, several means more than one, and multiple means more than two. Greater than, less than, exceeding, etc. are understood as not including the original number, and above, below, within, etc. are understood as including the original number. If the description of the first and second is only for the purpose of distinguishing the technical features, it cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features relation.

In the description of the present invention, unless otherwise clearly defined, words such as setting, installation, and connection should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

In the description of the present invention, reference to the terms "one embodiment," "some embodiments," "exemplary embodiments," "examples," "specific examples," or "some examples" is intended to mean that the embodiments are A specific feature, structure, material, or characteristic described by or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

In related technologies, the MQTT protocol is a lightweight communication protocol, and its characteristics such as small communication overhead and adaptability to unreliable networks make it widely used in today's Internet of Things field. However, since the MQTT protocol was originally designed in a private network environment, the focus is more on the lightness of message publishing and distribution, rather than some message processing or security during transmission. There are no other security measures other than username and password authentication. Today, with the rapid development of the Internet of Things, with the increase in the number of users, the corresponding security risks and problems are becoming increasingly prominent.

In the investigation and analysis of the communication status of the Internet of Things based on the MQTT protocol, it was found that a total of 78,829 agents communicated using the MQTT protocol under public network conditions, and port 1883 (the default communication port of the MQTT protocol, not using SSL/TLS) was used for communication. security authentication) accounted for 99.69%, that is, the vast majority of MQTT servers in the current public network environment have not implemented relevant security encryption measures for the communication process. Many research and practice results show that more than 60% of the servers do not verify the username and password of the client, and the vast majority of agents can use any client to subscribe to all topics and receive corresponding plaintext pushes.

This also shows from a practical point of view that the current status of communication based on the MQTT protocol is not optimistic. The embodiments of the present invention focus on data security in terms of transmission and storage processing, so the embodiments of the present invention do not consider analyzing some schemes that focus on subject authority control or schemes that focus on the performance of encryption and decryption algorithms. Among the solutions that focus on ensuring the security of data transmission, the SSL/TLS protocol solution and the emerging AugPAKE protocol solution are more common. However, since the AugPAKE scheme is a simplified version of the SSL/TLS scheme, it actually puts the authentication steps of the SSL/TLS scheme offline: the client and the agent need to be authenticated offline to ensure security. It does not apply to scenarios where the terminal exists. Moreover, the subsequent online execution process is similar to that of the SSL/TLS scheme, which is essentially for negotiating a symmetric key that will be used to ensure the security of data transmission, so repeated analysis of the two schemes is unnecessary.

The following analyzes the SSL/TLS protocol scheme, summarizes its shortcomings under the research focus of this patent, and then introduces the specific content of the embodiment of the present invention.

As shown in Figure 1, the SSL/TLS protocol solution is located between the application layer and the TCP/IP layer. In the network model shown in Figure 1, the SSL/TLS protocol scheme is mainly used to ensure the security of communication based on the TCP protocol. The basic encryption idea adopts the combination of asymmetric encryption and symmetric encryption. The encrypted communication process is as follows:

Step 1. The client initiates a request to the server for the public key of the server;

Step 2: The two parties negotiate the session key used in this session, which is a symmetric key;

Step 3: In the subsequent stage of this session, both parties use the negotiated session key to communicate.

The first two steps of communication are also called the handshake process, which is also the core part of the SSL/TLS protocol. It includes a series of negotiation of encryption-related information and determination of security parameters used in subsequent encryption.

Specifically, when the client requests encrypted communication for the first time, it sends a ClientHello request to the server, which mainly includes several fields: VersionNumber (the highest version of the TLS protocol currently supported), Randomly Generated Data (which will be used to generate session keys later) , Cipher Suite (cipher suite supported by the client), etc.;

After the server receives the ClientHello request from the client, it needs to send a response to the client. There are three main fields: ServerHello, ServerCertificate, and ServerHelloDone. The fields contained in ServerHello correspond to the fields in the ClientHello request sent by the client; ServerCertificate is a certificate provided by the server to the client for authenticating its own identity, which is used to prove the legitimacy of the server and pass the public key. Finally, ServerHelloDone indicates that the server response is complete, waiting for the client's subsequent response;

After receiving the response from the server, the client first verifies the legitimacy of the server's certificate. After the certificate validity authentication of the server is passed, the information sent by the client to the server mainly includes: the encrypted last random number PreMasterKey, ChangeCipherSpec and ClientFinished. ChangeCipherSpec means to use the previously negotiated cipher suite for subsequent communication encryption. ClientFinished indicates that the handshake of the client is completed, and this item is also the Hash value of all the content sent before, which is used for verification by the server;

After receiving the response sent by the client, the server first uses the corresponding private key to decrypt the last random number PreMasterKey, then combines the two random numbers in the previous communication process to calculate the symmetric key used in the subsequent session, and finally sends the The client sends the following messages: ChangeCipherSpecMessage and ServerFinishedMessage. The former is used to notify the client that it will use the previously negotiated symmetric key and encryption algorithm for communication in the future, and the latter indicates that the Hash value obtained by Hash calculation for the entire session is used for client authentication. After the client authentication is successful, the subsequent negotiation will be passed A good symmetric key for encrypted communication.

It can be seen from the above process that the SSL/TLS protocol negotiates the subsequent symmetric key used to encrypt data through an additional handshake process, thereby solving the security problem in data transmission. However, the solution based on the SSL/TLS protocol still has the following problems: First, it does not solve the possible security issues when messages are stored and processed on the agent side. For example, since more and more message agents are deployed to the cloud, assuming that the Intrusion, because the message is stored in plain text on the agent side, a large number of plain text messages are likely to be leaked and tampered with; second, the SSL/TLS protocol adds an additional handshake process in order to negotiate the subsequent symmetric key, that is, increase In the case of relatively congested network conditions, it may cause a burden for the pursuit of light and fast IoT communication, especially for the client in communication.

In order to have both the security of transmission and storage processing, especially to ensure the security of data storage and processing on the agent side, the most basic requirement is to ensure that the data is still encrypted when it is distributed and processed on the agent side. Then on the existing basis, the publisher client encrypts the original message part before publishing the message on a certain topic. In this way, as long as the selected encryption algorithm is appropriate and the key is not leaked, it can ensure that the message is maintained in an encrypted state during transmission and storage without revealing the original message content. And after the message agent forwards the message to the corresponding subscriber client, the subscriber client can use the key of the corresponding publisher to decrypt the ciphertext to obtain the original message.

However, assuming a symmetric encryption method is adopted, that is to say, the key k will exist in the hands of multiple clients, which increases the risk of the key being leaked. As long as a client is hacked and the key k is obtained, and a distribution agent is also hacked, then all subsequent message encryption is useless, and the attacker can decrypt all messages received by the distribution agent and tamper with them at will. . Assuming that the subscriber client itself may be disguised by an attacker, then the attacker can directly obtain the key k. Further, after the distribution agent is invaded, the encrypted message can be easily obtained by the attacker. decrypt. The use of asymmetric encryption can solve the problem that the key is easily leaked in the previous symmetric encryption. Assuming that each client has a pair of public and private keys: pubKey and privKey, then the publisher only needs to encrypt the original message with the public key of the subscriber client when publishing a message. After the subscriber client receives the encrypted message forwarded by the distribution agent, it can decrypt the original message with its own private key. Even if a client is hacked and its own private key is leaked, even if the distribution agent is hacked later, the attacker can only decrypt the message forwarded to the hacked client, because the public and private keys of each client are independent. However, this solution also has flaws: First, from the MQTT protocol communication model, it can be seen that the publisher itself does not know the information of the subscriber client on a certain topic, so it is impossible to know whether the published message will be forwarded by the distribution agent For which subscriber clients, the publisher does not know which subscriber client’s public key to use to encrypt the message; secondly, assuming that the publisher can know the topic of the current message to be published by modifying the original MQTT protocol Information about existing subscriber clients. However, since there may be multiple subscriber clients, the publisher client can only use the public key of one subscriber client to encrypt the original message when publishing a message. Since the public key information of the subscriber client is independent and irrelevant, this scheme cannot meet the requirements when there are multiple subscriber clients; again, suppose that the original MQTT protocol is modified in some way to make the publisher client A combination of multiple messages encrypted by different subscriber public keys can be transmitted at a time, and the distribution agent can correctly separate the encrypted messages belonging to different subscriber clients in the message and forward them to different subscriber clients. Then when the number of subscriber clients of a topic is large, the length of the PUBLISH message issued by the publisher client will be very long, and the client needs to store a large number of subscriber public keys and other information when it acts as a publisher. However, in actual scenarios, clients are often terminal devices with limited hardware resources such as memory and CPU. This solution is unbearable for these terminal devices.

To sum up, although the above scheme can guarantee the security of data in both transmission and storage processing, the security of the key for encrypting and decrypting messages cannot be guaranteed, and it cannot be guaranteed when there are a large number of clients. Effectively manage and control keys.

Based on this, embodiments of the present invention provide a control method, system and medium for message storage processing and security authentication. In this embodiment, by separating the security authentication of the MQTT protocol from the message storage and processing, the message agent with the message storage and processing function can be distributed in the cloud, which is recorded as a distribution agent, and the part with the message security authentication function is deployed separately. Denote it as a security certification center. Specifically, the interaction process of the distribution agent, the security authentication center, the publisher client and the subscriber client is shown in FIG. 2 . In the interactive system shown in Figure 2, as shown in Figure 3, the present invention provides a control method for message storage processing and security authentication, including the following steps:

S31. The security authentication center generates a process key according to the message key.

In this embodiment, the security certification center may be a trusted third-party organization, which is used to handle the following two items:

First, according to the request of the distribution agent, use the message key of the relevant publisher client and subscriber client to generate a process key, so that the subsequent distribution agent can use the process key to perform secondary encryption on the message ciphertext;

Second, use the generated exclusive public and private keys to encrypt and decrypt the message key of the client, and use the process key to solve the problem that the message is blocked due to the untrustworthiness of the distributed agent when the message is stored and processed in plain text on the distributed agent. A large number of leaks and tampering problems. At the same time, the security and control problems of the message key when there are a large number of clients are improved by monopolizing the public and private keys.

S32. The publisher client uses the message key to encrypt the original message to obtain the first encrypted message, and transmits the first encrypted message to the distribution agent.

In this embodiment, the publisher client uses the message key to encrypt the original message before publishing the message to the distribution agent. Since the message is already encrypted before transmission, it is difficult for the attacker to obtain the original text of the message without the message key being leaked, and there is no need to add an additional handshake process like the SSL/TLS scheme to negotiate the subsequent symmetry key.

S33. The distributed agent obtains the process key from the security authentication center, and uses the process key to encrypt the first encrypted message twice to obtain a second encrypted message.

In this embodiment, the distribution agent also needs to communicate with the security authentication center in order to obtain the process key for re-encrypting the message transmitted by the publisher. Each time a message is forwarded to a subscriber, the distribution agent uses the obtained process key to encrypt the message ciphertext transmitted by the publisher client twice to obtain a new ciphertext, and then forwards the processed result to the subscriber client. On the premise of only knowing the process key, the distribution agent cannot deduce the message key of the publisher or subscriber client, which also solves the problem of storing and processing messages in plain text on the agent side.

S34. The subscriber client receives the second encrypted message forwarded by the distribution agent, and decrypts the second encrypted message by using the message key to obtain the original message.

In this embodiment, a subscriber client is a client that receives messages on a subscribed topic. In this scheme, after the subscriber client receives the ciphertext encrypted twice by the distribution agent, it will decrypt the ciphertext with its own message key to obtain the original message. Similar to the publisher client, the message is still encrypted before the distribution agent forwards the data, and it is difficult for an attacker to obtain the original text of the message if the message key is not leaked.

In the implementation of the present invention, mainly use following three kinds of keys:

First, the message key. Message keys are symmetric keys used by publisher clients and subscriber clients to encrypt or decrypt messages. The publisher client will use its message key to encrypt the original message before publishing the message, and the subscriber client will eventually use its message key to decrypt the encrypted message. It should be noted that when the exclusive public and private keys are not used, the message key is generated and controlled by the security certification center, and there is no encrypted message key when the publisher client sends a message or the distribution agent forwards the message; when the exclusive When public and private keys are used, the message key of the publisher client will be generated by the publisher client, and the message key of the subscriber client will be generated by the security certification center, wherein the first encrypted message includes the message encrypted by the message key and by The message key encrypted by the exclusive public key; the second encrypted message includes the message encrypted by the process key and the message key of the subscriber client. It can be seen that since the message has been encrypted before transmission and forwarding, there is no need to perform an additional handshake process to negotiate a subsequent symmetric key like the SSL/TLS scheme, thus solving the need for an additional network for the SSL/TLS scheme The overhead that a round trip might cause.

Second, the process key. The process key is a symmetric key, which is generated by the security certification center using the message keys of the relevant publisher client and subscriber client and delivered to the distribution agent for use. Once encrypted, the encrypted data is still a ciphertext message, which can be directly decrypted by the subscriber client using its message key to obtain the original message. Also, the distribution agent cannot deduce the message key of the publisher or subscriber client from the process key alone. The process key is to solve the problem of storing and processing messages in clear text on the proxy side in the SSL/TLS scheme.

Third, monopolize public and private keys. It belongs to an asymmetric key, which is generated by the publisher client, subscriber client and security certification center, and is used to encrypt and decrypt the message key used by the publisher client and subscriber client. Exclusive public and private keys are mainly used to solve the problem of message key control and the security of message keys when there are a large number of clients in the scheme without security authentication.

In this embodiment, the process key process key procKeysrc-dest-T is jointly generated by the message keys encKeysrc and encKeydest of the publisher client and the subscriber client, and is only used by the distribution agent for the publisher The transmitted message ciphertext is encrypted twice, and the encrypted ciphertext is then decrypted by the subscriber client to obtain the original message content. The message key is jointly determined by the publisher client, subscriber client, and topic, and varies with different clients or topics.

Taking XOR encryption as an example, assuming that the message key of the publisher client is "00011010" and the message key of the subscriber client is "00000100", then the generated process key is the result of the XOR of the two message keys : "00011110". Assuming that the original text message to be encrypted is "abc", the ciphertext generated by the publisher client after encrypting it with its message key is: "{xy", and the distribution agent uses the process key to encrypt the ciphertext. The result after the second encryption is: "efg", the subscriber client uses its message key to decrypt the ciphertext after the second encryption, and finally obtains the original text of the message: "abc".

The publisher client uses the message key to encrypt the message to be published and sends the ciphertext to a node in the distribution agent cluster, and the subscriber client uses the message key to directly decrypt the received forwarded message to obtain the original message content. Unlike the client using the message key to encrypt and decrypt data, the distribution agent uses the process key to re-encrypt the ciphertext generated by encrypting the plaintext with the message key, and also needs to ensure the result of the second encryption It can be directly decrypted by the subscriber client to obtain the original message. At the same time, it is necessary to ensure that the distribution agent cannot derive the plaintext only through the process key, and the general encryption and decryption keys and corresponding encryption and decryption algorithms cannot meet the above conditions. Therefore, the process encryption The generation and encryption of the key need to have certain restrictions and requirements. Specifically, for the application of the process key, it has the following advantages:

From the application of the above-mentioned process key, it can be seen that the data is secure in both transmission and storage processing, and does not need to negotiate the subsequent symmetric key for encryption through an additional handshake process like the SSL/TLS scheme. There is no need to manage and control a large number of keys. Specifically, it can be understood as medical points: First, the data is encrypted during the transmission process, and the plaintext and ciphertext can only be encrypted and decrypted by the relevant encryption and decryption message key, and the message key is not leaked Under the premise, the security of data transmission is guaranteed, and there is no need to add an additional handshake process to negotiate keys like the SSL/TLS scheme; second, the distribution agent can only perform secondary The encryption process cannot independently derive the key information for decrypting the ciphertext, and the original message cannot be decrypted, which ensures the security of the message in storage and processing; third, for any topic T, different clients have different The encryption and decryption keys of this topic are independent and different, which ensures that even if a client and the distribution agent are invaded at the same time, it is impossible to leak and tamper with all the messages passing through the distribution agent on a large scale, which also ensures that the data Fourth, when each client needs to publish or decrypt a message on a certain topic, the key used is generated and managed by the certification center, which also solves the client management key problem mentioned above . Finally, after receiving the twice-encrypted message, the subscriber client can decrypt it to obtain the original message, which also ensures the integrity of the entire publishing and forwarding process.

In this embodiment, after the process key is used for secondary encryption, problems such as leakage and tampering of a large number of plaintext messages that may exist in the case of an untrustworthy distribution agent can be solved. But there are still two problems: the first is the issue of the message key control of the security certification center, and the second is the security issue of the message key. Specifically, the number of message keys that the security authentication center needs to control is proportional to the number of publisher clients and subscriber clients. In the case of a large number of publisher clients and subscriber clients, the management and control of a large number of message keys will bring an additional burden to the security authentication center, and further, may cause publisher clients, subscriber clients and The network communication between the distribution agent and the security certification center has a large delay, which eventually leads to a delay or even paralysis of the message release and distribution process. The security issue of the message key cannot be ignored either. If the client requests the message key and the security authentication center generates and returns the message key, the security of the message key in transmission cannot be guaranteed, and the attacker can skip the process key after intercepting the message key , easily obtain or tamper with the information that the publisher wants to publish, which will have a serious impact on the normal publishing and distribution process.

Therefore, in order to solve the above-mentioned problem, this embodiment enables the security authentication center to generate and control the number of message keys k*l*n, that is, it has nothing to do with the issuer, and the security of the message key is guaranteed. On the basis of the application process key, the message key is encrypted and decrypted using the exclusive public and private key. After the introduction of exclusive public and private keys, the processing content is also different:

The client has its own public and private keys, which are used to generate an exclusive public key for encrypting and decrypting the encrypted message key;

The message key of the publisher client is generated and managed by itself, while the message key of the subscriber client is generated by the security certification center;

The Security Certification Center manages public and private keys at the granularity of subjects, which are used to generate exclusive private keys for encrypting and decrypting message keys.

For each terminal in the interactive system shown in Figure 2, some changes have also taken place in the work:

The publisher client no longer requests the message key from the certificate authority but generates it by itself. The data sent to the distribution agent is divided into two parts: the message encrypted by the message key, and the message key encrypted by the exclusive public key;

When the distribution agent requests the process key, it not only needs to bring the corresponding client information, but also needs to bring the encrypted message key sent by the publisher. When forwarding data to the subscriber client, not only need to forward the twice encrypted ciphertext, but also need to bring the message key of the subscriber client returned by the security authentication center;

Before generating the process key, the security certification center first needs to use the exclusive private key to decrypt the encrypted message key transmitted by the distribution agent to obtain the publisher's message key, then randomly generate the message key of the subscriber client, and follow the above Request to generate a process key. After that, use the relevant exclusive private key to encrypt the message key of the subscriber client to prevent the distribution agent from obtaining the unencrypted message key. Finally, return the generated process key and encrypted subscriber client key to the distribution agent;

The message key used by the subscriber client to decrypt the message ciphertext is included in the data forwarded by the distribution agent. The subscriber client first uses the exclusive public key to decrypt the message key, and then uses the message key to decrypt the ciphertext to obtain the original message.

In this embodiment, when an exclusive public and private key is used, for the publisher client, the exclusive public key is used to encrypt the message key; for the subscriber client, the exclusive private key is used to decrypt the message key. Wherein, the security authentication center uses the exclusive private key of the publisher client to decrypt the publisher's message key, and uses the exclusive public key of the subscriber client to encrypt the message key of the subscriber client. Specifically, on the publisher client, a new exclusive public key pubKeysrc-T is generated by using the private key privKeysrc of the publisher client and the public key pubbKeyT of the corresponding topic, and the exclusive public key is used to encrypt messages on the publisher client. The message key is encrypted. When the certification center generates the process key, it uses the public key pubKeysrc of the publisher client and the private key privKeyT of the corresponding topic to generate an exclusive private key corresponding to the exclusive public key of the publisher client, so as to decrypt and obtain the encrypted message key of the publisher client .

The security of the optimized embodiment of the present invention is analyzed below according to the communication flow of each part.

First, the communication between the publisher client and the distribution agent:

The communication process between the publisher client and the distribution agent is one-way, that is, from the publisher client to the distribution agent, and the security of this communication process under various attack modes is analyzed.

Eavesdropping attack: Since the message key is randomly generated by the publisher client, the attacker cannot steal the encryption key. During the transmission process, both the key and the message are encrypted. The attacker can only obtain the encrypted message and the message key, but cannot obtain the plaintext of the message, and cannot eavesdrop or leak the corresponding message. . This also ensures the security of data during transmission.

Man-in-the-middle attack: After the corresponding ciphertext and encrypted message key are generated, the relevant message will be sent to the distribution agent. On the premise that the message key has not been leaked, if the man-in-the-middle wants to carry out an attack, it needs to first To decrypt the message key, two conditions need to be met: 1) steal or crack the publisher's private key; 2) generate the corresponding exclusive public key through the exclusive public and private key generation algorithm. It can be seen that under normal circumstances, these two points are difficult to obtain information for the attacker, so it is difficult for the middleman to carry out the attack.

The distribution agent is untrustworthy: Assume that a node in the distribution agent cluster is successfully invaded by an attacker through some means, because the messages transmitted from the publisher to the distribution agent are all encrypted: the message body is encrypted by a randomly generated message key , and the message key is encrypted with the exclusive public key. The data encrypted by the exclusive public key can only be decrypted by the corresponding exclusive private key, and the corresponding exclusive private key can only be calculated and derived by the certification center. Therefore, even if an attacker successfully invades a distribution agent node, he will not be able to obtain the plaintext content of the relevant messages, which solves the problem of leaking and tampering of a large number of plaintext messages that may occur when the distribution agent is untrustworthy, thereby ensuring that the data is stored Security in Handling.

Second, the communication between the distribution agent and the certification authority:

The communication between the distribution agent and the certification center is two-way, and the process key request and response process is mainly carried out between the two. Since the distribution agent and the certification center do not have the hardware limitations of the client in the Internet of Things environment, such as memory and Computing capacity limitations and other issues, so the communication between the two can be solved through the existing solution, that is, the SSL/TLS protocol solution. Due to the use of the SSL/TLS protocol scheme, a series of attack methods such as corresponding eavesdropping attacks and man-in-the-middle attacks cannot take effect. In addition, even if the distribution agent is invaded, since the data transmitted during the entire communication process is encrypted, the attacker can only obtain the process key returned by the authentication center and the encrypted message key of the subscriber client: for the process key As far as the encryption key is concerned, the publisher cannot independently push out the encryption key of the publisher or subscriber client through the process key, so the attacker cannot decrypt the original message through the process key. For the encrypted message key of the subscriber client, its decryption needs to obtain the exclusive public key generated by the subscriber client first, and this process needs to use the private key of the subscriber client, but the private key of the subscriber client The key is unique to it, which also ensures the security of data storage and processing.

Third, the communication between the distribution agent and the subscriber client:

The communication between the distribution agent and the subscriber client is also one-way, and the distribution agent forwards and pushes the ciphertext and the encrypted message key to the corresponding subscriber client.

The following analyzes the security of the communication process:

Eavesdropping attack: The message key and the corresponding ciphertext are encrypted during the transmission process. The attacker cannot deduce the corresponding plaintext based on the ciphertext alone, but can only obtain the plaintext content indirectly by cracking the encryption key first. The message key is encrypted by the relevant exclusive private key, and only the subscriber client can calculate and derive the corresponding exclusive public key. Therefore, the attacker cannot obtain the original plaintext message content, which also ensures the security of the data during transmission.

Man-in-the-middle attack: Similar to the communication process from the publisher to the distribution agent, if the message key is not leaked, the man-in-the-middle needs to meet two conditions to carry out the attack: 1) steal or crack the publisher’s private key; 2) pass The exclusive public key generation algorithm generates the corresponding exclusive public key. These two points are difficult for an attacker to satisfy, so it is difficult for a man-in-the-middle to carry out an attack.

The distribution agent is untrustworthy: similar to the publisher, assuming that a node in the distribution agent cluster is successfully invaded by an attacker through some means, because the data that the distribution agent is going to forward to the subscriber client is in an encrypted state: the content of the message is encrypted through the process of encryption. The key is encrypted twice, and the message key of the subscriber client is encrypted with the exclusive private key. The data encrypted by the exclusive private key can only be decrypted by the corresponding exclusive public key, and the corresponding exclusive public key can only be calculated and derived by the subscriber client. Therefore, even if an attacker successfully invades a distribution agent node, he will not be able to obtain the plaintext content of the relevant messages, which solves the problem of leaking and tampering of a large number of plaintext messages that may occur when the distribution agent is untrustworthy, thereby ensuring that the data is stored Security in Handling.

In summary, the message storage and security authentication separation scheme proposed by the embodiment of the present invention is both safe and effective in theory, and improves the security and management of message keys. At the same time, the overall performance of the MQTT protocol adopted is better than that of the MQTT protocol using the SSL/TLS solution. Compared with the original MQTT protocol, the MQTT protocol based on the improved solution is better in both performance indicators and data security. A better compromise has been achieved.

An embodiment of the present invention provides a control system for message storage processing and security authentication, including:

The publisher client is used to encrypt the original message using the message key to obtain a first encrypted message, and transmit the first encrypted message to the distribution agent;

The content of the method embodiment of the present invention is applicable to the system embodiment. The functions realized by the system embodiment are the same as those of the method embodiment above, and the beneficial effects achieved are also the same as those achieved by the above method.

An embodiment of the present invention provides a storage medium, in which a computer-executable program is stored, and when the computer-executable program is executed by a processor, it is used to implement the message storage processing and security authentication as shown in FIG. 3 Control Method.

The embodiment of the present invention also discloses a computer program product or computer program, where the computer program product or computer program includes computer instructions, and the computer instructions are stored in a computer-readable storage medium. The processor of the computer device can read the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computer device executes the control method for message storage processing and security authentication shown in FIG. 3 .

The embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned embodiments, and within the scope of knowledge of those of ordinary skill in the art, various modifications can be made without departing from the spirit of the present invention. Variety. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other if there is no conflict.

Claims

A control method for message storage processing and security authentication, characterized in that it includes the following steps:

The security certification center generates a process key according to the message key;

The publisher client uses the message key to encrypt the original message to obtain a first encrypted message, and transmits the first encrypted message to the distribution agent;

The distributed agent obtains the process key from the security authentication center, and uses the process key to encrypt the first encrypted message twice to obtain a second encrypted message;

The subscriber client receives the second encrypted message forwarded by the distribution agent, and uses the message key to decrypt the second encrypted message to obtain an original message.
A control method for message storage processing and security authentication according to claim 1, characterized in that, the security authentication center generates a message key of a topic message, and manages and controls the message key.
A control method for message storage processing and security authentication according to claim 1, characterized in that, when the message key is encrypted or decrypted according to the exclusive public and private key, it is generated and managed by the publisher client The message key of the topic message in the publisher client, and the message key of the topic message in the subscriber client is generated by the security certification center.
A control method for message storage processing and security authentication according to claim 3, wherein the message key and the process key are both symmetric keys; the exclusive public-private key is asymmetric key.
A control method for message storage processing and security authentication according to claim 3, wherein the first encrypted message includes a message encrypted by a message key and a message key encrypted by an exclusive public key ; The second encrypted message includes the message encrypted by the process key and the message key of the subscriber client.
A control method for message storage processing and security authentication according to claim 5, characterized in that, the distributed agent requests a process from the security authentication center through the message key encrypted by the client information and the exclusive public key Key, the client information includes subscriber client information and publisher client information.
A control method for message storage processing and security authentication according to claim 6, wherein the security authentication center encrypts the exclusive public key sent by the distributed agent with the exclusive private key before generating the process key The final message key is decrypted to obtain the message key of the publisher client, and the message key of the subscriber client is randomly generated according to the message key of the publisher client, and the message key of the subscriber client is encrypted by the exclusive private key. encryption.
A control method for message storage processing and security authentication according to claim 7, wherein the subscriber client uses the exclusive public key to decrypt the message key encrypted by the exclusive private key, and The decrypted message key decrypts the message encrypted by the process key in the second encrypted message to obtain the original message.
A control system for message storage processing and security authentication, characterized in that it includes:

Security certification center, used to generate process key according to message key;

The publisher client is configured to use the message key to encrypt the original message to obtain a first encrypted message, and transmit the first encrypted message to the distribution agent;

a distributed agent, configured to obtain the process key from the security certification center, and use the process key to encrypt the first encrypted message twice to obtain a second encrypted message;

The subscriber client is configured to receive the second encrypted message forwarded by the distribution agent, and use the message key to decrypt the second encrypted message to obtain an original message.
A storage medium, characterized in that a computer-executable program is stored therein, and when the computer-executable program is executed by a processor, it is used to implement the message storage process according to any one of claims 1-8 and security authentication control methods.