Fault-tolerant strategy selection method and system for intelligent edge computing gateway

Abstract

The fault-tolerant strategy selection method and system of the intelligent edge computing network gate provided in the embodiment of the present application determines the business session statistical log of the task process and analyzes the target business session based on the business session statistical log. In this way, when the number of target business sessions in the set time period is greater than the first set judgment value, a session risk prompt is issued, which realizes efficient and accurate analysis of the business session security risk under the overall business session process under the policy usage state, thereby ensuring the credibility of the session risk prompt. In this way, different fault-tolerant strategies can be selected for different task processes according to the session risk prompt, thereby ensuring the stability of the relevant data security risk strategy in the subsequent business session process and improving the risk response capability of the data security risk strategy.

Description

Technical Field

[0001] The present application relates to the field of intelligent edge computing and network gateway technology, and in particular to a fault-tolerant strategy selection method and system for an intelligent edge computing network gateway. Background Art

[0002] A network gate is an information security device that uses a solid-state switch read-write medium with multiple control functions to connect two independent host systems. Since the two independent host systems are isolated by the network gate, there is no physical connection, logical connection, or information transmission protocol for communication between the systems. There is no information exchange based on the protocol, but only non-protocol ferrying in the form of data files. However, when the network gate is applied to the edge computing architecture, how to achieve security risk handling of data information is a technical issue that is currently being focused on. Summary of the invention

[0003] In order to improve the technical problems existing in the related technologies, the present application provides a fault-tolerant strategy selection method and system for an intelligent edge computing gateway.

[0004] In the first aspect, an embodiment of the present application provides a fault-tolerant strategy selection method for an intelligent edge computing network firewall, which is applied to a fault-tolerant strategy selection system in an edge computing environment, wherein the edge computing environment also covers an edge computing network firewall matched with a first task process and a second task process, wherein the first task process is a target process corresponding to a policy activation state, and the second task process is a target process corresponding to a policy termination state, wherein the method comprises: determining a business session statistical log of the task process, wherein the business session statistical log comprises a statistical time period, business session content, session subject, and task process label; performing target business session analysis according to the business session statistical log; the target business session is a business session whose corresponding session subject when switching to a policy activation state is inconsistent with the corresponding session subject when switching to a policy termination state; when the number of the target business sessions within a set time period is greater than a first set judgment value, a session risk prompt is performed, and a fault-tolerant strategy is selected for the first task process and the second task process according to the session risk prompt, wherein the fault-tolerant strategy is a data security risk control strategy.

[0005] In this way, by determining the business session statistics log of the task process and analyzing the target business session based on the business session statistics log, when the number of target business sessions in the set time period is greater than the first set judgment value, a session risk prompt is issued, achieving efficient and accurate analysis of the business session security risks under the overall business session process under the policy usage state, thereby ensuring the credibility of the session risk prompt. In this way, different fault tolerance strategies can be selected for different task processes based on the session risk prompt, thereby ensuring the stability of the relevant data security risk strategy in the subsequent business session process and improving the risk response capability of the data security risk strategy.

[0006] Optionally, the target business session analysis is performed based on the business session statistical log, including: when the second type of statistical log of any group of business sessions is determined, searching whether the first type of statistical log of the business session exists; the second type of statistical log is the business session statistical log of the second task process, and the first type of statistical log is the business session statistical log of the first task process; if so, associating the second session topic in the second type of statistical log and the first session topic in the first type of statistical log; if the second session topic indicates an inconsistent session topic with the first session topic, determining that the business session is a target business session.

[0007] Optionally, the searching whether there is a first type of statistical log of the service session includes:

[0008] Determine the corresponding statistical time period interval according to the statistical time period in the second type of statistical log; wherein the statistical time period interval uses the statistical time period as the termination period and uses the quantitative difference between the statistical time period and the set time period step as the trigger period; retrieve from the first type of statistical log of the statistical time period within the statistical time period interval whether there is the first type of statistical log of the business session.

[0009] Optionally, when the number of the target business sessions within the set time period is greater than a first set judgment value, a session risk warning is issued, including: when the target business session is analyzed, the cached session risk warning cumulative value is updated according to the set method; when the cached session risk warning cumulative value reaches a second set judgment value, according to the statistical time period in the business session statistical log of the analyzed target business session, determine whether the number of the target business sessions within the set time period with the current time period as the end time period is greater than the first set judgment value, and when the number of the target business sessions within the set time period with the current time period as the end time period is not greater than the first set judgment value, continue to analyze the target business session, and when the cached session risk warning cumulative value reaches the second set judgment value and the number of the target business sessions within the set time period with the current time period as the end time period is greater than the first set judgment value, a session risk warning is issued.

[0010] Optionally, after the session risk prompt is performed, the method further includes: initializing a cached session risk prompt cumulative value.

[0011] Optionally, the providing a session risk warning includes: determining a type of security risk of the business session; and providing a risk warning according to the type of security risk of the business session.

[0012] Optionally, after analyzing the target business session according to the business session statistical log, the method further includes: for any of the analyzed target business sessions, adding a risk keyword of the target business session to a risk information set, the risk keyword including a session topic and a business session content corresponding to the session topic of the target business session in the statistical time period of the first task process, the statistical time period of the second task process, and the switching to the policy activation state, and the risk keywords of each target business session in the risk information set are sorted in a first-to-last order according to the statistical time period of the target business session in the first task process; determining the type of business session security risk includes: according to the risk keyword of the first business session, retrieving the business session statistical log of a set number of second business sessions that switched to the policy activation state before the first business session; wherein the risk keyword of the first business session is the first risk keyword in the risk information set, and the session topic corresponding to the second business session when switching to the policy activation state is the same as the session topic corresponding to the first business session when switching to the policy activation state; determining the type of business session security risk according to the business session statistical log of the second business session in the second task process.

[0013] Optionally, the set number has a value ranging from 3 to positive infinity; identifying the type of business session security risk based on the business session statistical log of the second business session in the second task process includes: retrieving the business session statistical log of the second business session in the second task process; if the number of second business sessions in the business session statistical log of the second task process that is not retrieved is the first set value, determining the type of business session security risk to be a first information risk type; the first information risk type indicates that there is an information risk in the business session; if the number of second business sessions in the business session statistical log of the second task process that is not retrieved is the second set value, determining the type of business session security risk to be a second information risk type; the second information risk type indicates that there is information intrusion in the business session; if the number of second business sessions in the business session statistical log of the second task process that is not retrieved is 3 to positive infinity, determining the type of business session security risk to be a third information risk type; the third information risk type indicates that there is intrusion associated with the business session.

[0014] Optionally, after identifying the type of security risk of the business session, the method further includes: storing the business session content of the second business session for which the business session statistical log of the second task process has not been retrieved; after providing the session risk prompt, the method further includes: for any second business session for which the business session statistical log of the second task process has not been retrieved, when it is determined that the second business session is in the business session statistical log of the second task process, cleaning the cached business session content of the second business session and terminating the risk prompt for the second business session;

[0015] After the session risk warning is performed, it also includes: for any second business session for which the business session statistics log in the second task process is not retrieved, when it is determined that the time period for which the second business session is in the policy activation state is greater than the set time period judgment value, the cached business session content of the second target business session is cleaned, and the risk warning for the second business session is terminated.

[0016] In a second aspect, the present application also provides a fault-tolerant strategy selection system, comprising a processor and a memory; the processor and the memory are communicatively connected, and the processor is used to read a computer program from the memory and execute it to implement the method described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings herein are incorporated in and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the description, are used to explain the principles of the present application.

[0018] Figure 1It is a hardware structure diagram of a fault-tolerant strategy selection system provided in an embodiment of the present application.

[0019] Figure 2 It is a flow chart of a fault-tolerant strategy selection method for an intelligent edge computing network gateway provided in an embodiment of the present application. DETAILED DESCRIPTION

[0020] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0021] It should be noted that the terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0022] The method embodiment provided in the embodiment of the present application can be executed in a fault-tolerant strategy selection system, a computer device or a similar computing device. Taking running on a fault-tolerant strategy selection system as an example, Figure 1 1 is a hardware structure block diagram of a fault-tolerant strategy selection system for implementing a fault-tolerant strategy selection method for an intelligent edge computing gateway in an embodiment of the present application. Figure 1 As shown, the fault-tolerant strategy selection system 10 may include one or more ( Figure 1 Only one is shown in the figure) a processor 102 (the processor 102 may include but is not limited to a processing device such as a microprocessor MCU or a programmable logic device FPGA) and a memory 104 for storing data. Optionally, the above-mentioned fault-tolerant strategy selection system may also include a transmission device 106 for communication functions. It can be understood by those skilled in the art that Figure 1 The structure shown is only for illustration and does not limit the structure of the above-mentioned fault-tolerant strategy selection system. Figure 1 More or fewer components as shown, or with Figure 1 Different configurations are shown.

[0023] The memory 104 can be used to store computer programs, for example, software programs and modules of application software, such as a computer program corresponding to a fault-tolerant strategy selection method of an intelligent edge computing network gate in an embodiment of the present application. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, that is, implementing the above method. The memory 104 may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include a memory remotely arranged relative to the processor 102, and these remote memories may be connected to the fault-tolerant strategy selection system 10 via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0024] The transmission device 106 is used to receive or send data via a network. The specific example of the above network may include a wireless network provided by a communication provider of the fault-tolerant strategy selection system 10. In one example, the transmission device 106 includes a network adapter (Network Interface Controller, referred to as NIC), which can be connected to other network devices through a base station so as to communicate with the Internet. In one example, the transmission device 106 can be a radio frequency (Radio Frequency, referred to as RF) module, which is used to communicate with the Internet wirelessly.

[0025] Based on this, see Figure 2 , Figure 2 It is a flow chart of a fault-tolerant strategy selection method for an intelligent edge computing network gateway provided by an embodiment of the present invention. The method is applied to a fault-tolerant strategy selection system in an edge computing environment. The edge computing environment also covers an edge computing network gateway that matches a first task process and a second task process. The first task process is the target process corresponding to the policy activation state, and the second task process is the target process corresponding to the policy termination state. It may further include the technical solutions described below.

[0026] Step 21: Determine the business session statistics log of the task process, wherein the business session statistics log includes a statistical period, business session content, session subject, and task process label.

[0027] Step 22: Analyze the target business session according to the business session statistics log; the target business session is a business session whose corresponding session subject when switched to the policy activation state is inconsistent with the corresponding session subject when switched to the policy termination state.

[0028] For an illustrative embodiment, the target business session analysis recorded in step 22 according to the business session statistical log may specifically include the following contents: when the second type of statistical log of any group of business sessions is determined, whether the first type of statistical log of the business session exists is retrieved; the second type of statistical log is the business session statistical log of the second task process, and the first type of statistical log is the business session statistical log of the first task process; if it exists, the second session topic in the second type of statistical log and the first session topic in the first type of statistical log are associated and processed; if the second session topic and the first session topic indicate inconsistent session topics, the business session is determined to be the target business session. In this way, the first type of statistical log is first retrieved, and then different judgment results are analyzed for the first type of statistical log, and then the credibility and reliability of the target business session are determined.

[0029] For an illustrative embodiment, the above-mentioned recorded search for whether there is a first type of statistical log of the service session may specifically include the following contents: determining a corresponding statistical period interval according to the statistical period in the second type of statistical log; wherein the statistical period interval uses the statistical period as the termination period and uses the quantitative difference between the statistical period and the set period step as the trigger period;

[0030] From the first type of statistical logs within the statistical time period, it is searched whether there is a first type of statistical log for the service session.

[0031] Step 23: When the number of the target business sessions within a set time period is greater than a first set judgment value, a session risk prompt is issued, and a fault tolerance strategy is selected for the first task process and the second task process according to the session risk prompt, and the fault tolerance strategy is a data security risk control strategy.

[0032] For an illustrative embodiment, when the number of the target business sessions within the set time period is greater than the first set judgment value recorded in step 23, a session risk warning is issued, which may specifically include the following steps 231 and 232: Step 231, when the target business session is analyzed, the cached session risk warning cumulative value is updated according to the set method; Step 232, when the cached session risk warning cumulative value reaches the second set judgment value, according to the statistical period in the business session statistical log of the analyzed target business session, determine whether the number of the target business sessions within the set time period with the current period as the end period is greater than the first set judgment value, and when the number of the target business sessions within the set time period with the current period as the end period is not greater than the first set judgment value, continue to analyze the target business session, and when the cached session risk warning cumulative value reaches the second set judgment value and the number of the target business sessions within the set time period with the current period as the end period is greater than the first set judgment value, a session risk warning is issued.

[0033] For an illustrative embodiment, after performing the session risk prompt, the method may further include: initializing the cached session risk prompt cumulative value.

[0034] For an illustrative embodiment, the performing of session risk prompt may specifically include: determining the type of security risk of the business session; and performing risk prompt according to the type of security risk of the business session.

[0035] For an illustrative embodiment, after analyzing the target business session according to the business session statistical log, the method may also include: for any of the analyzed target business sessions, adding risk keywords of the target business session to the risk information set, the risk keywords include the session topic of the target business session during the statistical time period of the first task process, the statistical time period of the second task process, and the corresponding session topic when switching to the policy activation state, as well as the business session content, and the risk keywords of each target business session in the risk information set are arranged in a first-to-last order according to the statistical time period of the target business session in the first task process.

[0036] For an illustrative embodiment, the determination of the type of security risk of a business session may specifically include the following description: based on the risk keyword of the first business session, retrieving the business session statistical logs of the set number of second business sessions that switched to the policy activation state before the first business session. In the embodiment of the present application, the risk keyword of the first business session is the first risk keyword in the risk information set, and the corresponding session topic when the second business session switches to the policy activation state is the same as the corresponding session topic when the first business session switches to the policy activation state; based on the business session statistical log of the second business session in the second task process, the type of security risk of the business session is determined. In this way, the type of security risk of the business session is counted based on the risk keywords of the business session, which can improve the efficiency of determining the type of security risk of the business session, and further ensure the integrity of the type of security risk of the business session.

[0037] For an illustrative embodiment, the value of the set number is 3 to positive infinity. Based on this, the above-described identification of the type of business session security risk based on the business session statistical log of the second business session in the second task process may specifically include the following contents: retrieving the business session statistical log of the second business session in the second task process; if the number of second business sessions in the business session statistical log of the second task process that is not retrieved is the first set value, then determining the type of business session security risk is the first information risk type; the first information risk type indicates that there is an information risk in the business session; if the number of second business sessions in the business session statistical log of the second task process that is not retrieved is the second set value, then determining the type of business session security risk is the second information risk type; the second information risk type indicates that there is an information intrusion behavior in the business session; if the number of second business sessions in the business session statistical log of the second task process that is not retrieved is 3 to positive infinity, then determining the type of business session security risk is the third information risk type; the third information risk type indicates that there is an intrusion behavior associated with the business session.

[0038] For an illustrative embodiment, after identifying the type of security risk of the business session, the method further includes: storing the business session content of the second business session for which the business session statistical log of the second task process is not retrieved.

[0039] Furthermore, after the session risk prompt is performed, the method further includes: for any second business session whose business session statistics log in the second task process is not retrieved, when it is determined that the second business session is in the business session statistics log of the second task process, cleaning the cached business session content of the second business session and terminating the risk prompt for the second business session. In this way, the efficiency of the session risk prompt can be improved.

[0040] Furthermore, after the session risk prompt is performed, the process may further include: for any second business session for which the business session statistics log in the second task process is not retrieved, when it is determined that the period of time during which the second business session is in the policy activation state is greater than the set period determination value, cleaning the cached business session content of the second target business session and terminating the risk prompt for the second business session. In this way, the efficiency of the session risk prompt can be improved.

[0041] In summary, by determining the business session statistics log of the task process and analyzing the target business session based on the business session statistics log, when the number of target business sessions in the set period is greater than the first set judgment value, a session risk prompt is issued, achieving efficient and accurate analysis of the business session security risks under the overall business session process under the policy usage state, thereby ensuring the credibility of the session risk prompt. In this way, different fault-tolerant strategies can be selected for different task processes based on the session risk prompt, thereby ensuring the stability of the relevant data security risk strategy in the subsequent business session process and improving the risk response capability of the data security risk strategy.

[0042] Furthermore, a readable storage medium is provided, on which a program is stored, and the program implements the above method when executed by a processor.

[0043] In several embodiments provided in the embodiments of the present application, it should be understood that the disclosed device and method can also be implemented in other ways. The device and method embodiments described above are merely schematic, for example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the device, method and computer program product according to multiple embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the module, a program segment or a part of a code contains one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0044] In addition, the functional modules in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0045] If the function is implemented in the form of a software function module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions to enable a computer device (which can be a personal computer, a media service server 10, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program code. It should be noted that in this article, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements that are not explicitly listed, or also includes elements inherent to such a process, method, article or device. Without more constraints, an element defined by the phrase "comprising a..." does not exclude the existence of other identical elements in the process, method, article or apparatus comprising the element.

[0046] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A fault-tolerant strategy selection method for an intelligent edge computing gateway, characterized in that: A fault-tolerant strategy selection system applied to an edge computing environment, wherein the edge computing environment further includes an edge computing gateway matched to a first task process and a second task process, wherein the first task process is a target process corresponding to a policy activation state, and the second task process is a target process corresponding to a policy suspension state, wherein the method comprises: Determine a business session statistics log of the task process, wherein the business session statistics log includes a statistical period, business session content, session topic, and task process label; According to the business session statistical log, target business session analysis is performed; the target business session is a business session whose corresponding session topic when switched to the policy activation state is inconsistent with the corresponding session topic when switched to the policy termination state; When the number of the target business sessions within a set time period is greater than a first set determination value, a session risk prompt is issued, and a fault tolerance strategy is selected for the first task process and the second task process according to the session risk prompt, wherein the fault tolerance strategy is a data security risk control strategy; The performing target service session analysis according to the service session statistical log includes: When the second type of statistical log of any group of business sessions is determined, it is searched whether there is a first type of statistical log of the business session; the second type of statistical log is the business session statistical log of the second task process, and the first type of statistical log is the business session statistical log of the first task process; If so, the second conversation topic in the second type of statistical log and the first conversation topic in the first type of statistical log are processed in an associated manner; If the second session topic indicates an inconsistent session topic with the first session topic, determining the service session as a target service session; The providing of session risk warning includes: determining the type of security risk of the business session; providing risk warning according to the type of security risk of the business session; After performing target service session analysis according to the service session statistical log, the method further includes: For any of the target business sessions analyzed, a risk keyword of the target business session is added to the risk information set, the risk keyword including the session topic of the target business session in the statistical period of the first task process, the statistical period of the second task process, and the corresponding session topic when switching to the policy activation state, and the business session content, and the risk keywords of each target business session in the risk information set are sorted according to the rule of first to last in the statistical period of the target business session in the first task process; Determining the type of security risk of the business session includes: Retrieving the business session statistical logs of a set number of second business sessions that were switched to the policy activation state before the first business session according to the risk keyword of the first business session; wherein the risk keyword of the first business session is the first risk keyword in the risk information set, and the corresponding session topic when the second business session is switched to the policy activation state is the same as the corresponding session topic when the first business session is switched to the policy activation state; Determine a security risk type of the business session according to a business session statistical log of the second business session in the second task process.

2. The method according to claim 1, characterized in that The searching whether there is a first type of statistical log of the service session includes: According to the statistical period in the second type of statistical log, a corresponding statistical period interval is determined; wherein the statistical period interval uses the statistical period as the termination period and uses the quantitative difference between the statistical period and the set period step as the trigger period; From the first type of statistical logs within the statistical time period, it is searched whether there is a first type of statistical log for the service session.

3. The method according to claim 1, characterized in that When the number of the target service sessions within the set time period is greater than the first set determination value, a session risk prompt is issued, including: When the target business session is analyzed, the cached session risk warning cumulative value is updated according to the set method; When the cached session risk warning cumulative value reaches the second set judgment value, determine whether the number of the target business sessions within the set time period with the current time period as the end time period is greater than the first set judgment value based on the statistical time period in the business session statistical log of the target business session that has been analyzed, and when the number of the target business sessions within the set time period with the current time period as the end time period is not greater than the first set judgment value, continue to analyze the target business sessions, and when the cached session risk warning cumulative value reaches the second set judgment value and the number of the target business sessions within the set time period with the current time period as the end time period is greater than the first set judgment value, issue a session risk warning.

4. The method according to claim 3, characterized in that After the session risk prompt is performed, the method further includes: initializing the cached session risk prompt cumulative value.

5. The method according to claim 1, characterized in that The value of the set number is 3 to positive infinity; and the identifying the type of security risk of the business session according to the business session statistical log of the second business session in the second task process includes: Retrieving a business session statistics log of the second business session in the second task process; If the number of second business sessions in the business session statistics log of the second task process is not retrieved to be the first set value, determining the business session security risk type to be the first information risk type; the first information risk type indicates that there is an information risk in the business session; If the number of second business sessions in the business session statistics log of the second task process is not retrieved to be the second set value, determining that the business session security risk type is a second information risk type; the second information risk type indicates that there is a business session information intrusion behavior; If the number of second business sessions in the business session statistical log of the second task process is not retrieved and the value is between 3 and positive infinity, the business session security risk type is determined to be the third information risk type; the third information risk type indicates the presence of business session-associated intrusion behavior.

6. The method according to claim 5, characterized in that After the business session security risk type is identified, the method further includes: storing the business session content of the second business session for which the business session statistical log of the second task process is not retrieved; After the session risk warning is performed, the method further includes: for any second business session for which the business session statistics log of the second task process is not retrieved, when it is determined that the second business session is in the business session statistics log of the second task process, cleaning the cached business session content of the second business session and terminating the risk warning for the second business session; After the session risk warning is performed, the method also includes: for any second business session for which the business session statistics log in the second task process is not retrieved, when it is determined that the time period during which the second business session is in the policy activation state is greater than the set time period judgment value, cleaning the cached business session content of the second business session and terminating the risk warning for the second business session.

7. A fault-tolerant strategy selection system, characterized in that: It comprises a processor and a memory; the processor and the memory are communicatively connected, and the processor is used to read a computer program from the memory and execute it to implement the method described in any one of claims 1 to 6.

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