Distributed KVM system and method based on national secret SVAC video coding

Abstract

The present invention discloses a distributed KVM system and method based on national secret SVAC video coding, which relates to the field of computer technology, including obtaining access control records; determining a first risk value; determining a second risk value of a target user according to the access control records on each target computer terminal; judging whether the target user has an abnormality based on the first risk value and the second risk value of the target user, if an abnormality exists, closing the target user's access control authority to the target computer terminal, and performing identity authentication on the target user; if no abnormality exists, not restricting the target user's access control authority to the target computer terminal; performing SVAC2 encryption encoding on the audio and video data of the computer terminal; the present invention determines the first risk value and the second risk value through the user's access control behavior, performs abnormal analysis on the user, and reduces the security risks brought by the user to the KVM data.

Description

Technical Field

[0001] The present invention relates to the field of computer technology, and in particular to a distributed KVM system and method based on national secret SVAC video coding. Background Art

[0002] In the computer room management system, KVM (keyboard, video, mouse) is the most commonly used device. Through this device, a set of mouse and keyboard can be used to access and control multiple target hosts, which greatly simplifies the equipment. The traditional distributed KVM system uses H.264 or H.265 non-encrypted plaintext video encoding to transmit KVM data streams, which poses network security risks of KVM data being tampered with, monitored, and hijacked; in addition, in a multi-user and multi-tasking environment, users' access operations to KVM data bring the risk of data leakage or unauthorized access; therefore, how to increase the security of KVM data in a multi-user and multi-tasking environment has become an urgent problem to be solved. Summary of the invention

[0003] The purpose of the present invention is to provide a distributed KVM system and method based on national secret SVAC video coding to solve the problems raised in the above background technology.

[0004] In one aspect of the present invention, a distributed KVM method based on national secret SVAC video coding is provided, comprising:

[0005] S11, obtaining the target user's access control record to the computer terminal;

[0006] S12, determining a first risk value of the target user according to the target user's access control record to the target computer terminal; the target computer terminal is a computer terminal to which the target user holds access control authority;

[0007] S13, determining a second risk value of the target user according to the access control records of all users on each target computer terminal;

[0008] S14, judging whether the target user has abnormality based on the first risk value and the second risk value of the target user,

[0009] If there is an abnormality, the target user's access control authority to the target computer terminal is closed, and the target user's identity is authenticated. If the target user passes the identity authentication, the authority is opened again, and the first risk value and the second risk value at this time are marked as normal data. If the identity authentication is not passed, the first risk value and the second risk value at this time are marked as abnormal data;

[0010] If there is no abnormality, the target user's access control authority to the target computer terminal will not be restricted;

[0011] S15, the target user controls the access to the target computer terminal through his own authority, and performs SVAC2 encryption encoding on the audio and video data of the computer terminal. Based on the received audio and video data, the target user performs access control management on the signals of all computer terminals through a set of keyboard and mouse hotkey switches.

[0012] In step S12, the first risk value of the target user is determined according to the access control record of the target user to the target computer terminal, and further includes the following steps:

[0013] S21, within an access control cycle, obtain the target user's access control sequence for the target computer terminal; starting from the first computer terminal accessed and controlled by the target user, ignore the computer terminals that are repeatedly accessed and controlled, and after the target user has access control behavior on all target computer terminals, obtain the target user's access control sequence for the target computer terminals in chronological order; an access control cycle is determined according to the user's task schedule, and when the user's task is to perform access control on the computer terminal signal once every hour, the access control cycle can be set to one hour;

[0014] S22, the target user's access control sequence to the target computer terminal is represented by the index number of the target computer terminal. In the historical data of the target user, the number of occurrences of different access control sequences of the target user to the target computer terminal is determined, and the mode of the number of occurrences is found. The access control sequence corresponding to the mode is the benchmark access control sequence. The absolute error and SE between the target user's access control sequence to the target computer terminal and the benchmark access control sequence are calculated. d1 i is the sequence position of the i-th target computer terminal in the target user's access control sequence to the target computer terminal, d2 i The position of the i-th target computer terminal in the benchmark access control sequence, m is the number of target computer terminals; the order risk f is determined based on the absolute error and SE, SE min is the minimum value of the absolute error sum between the historical access control sequence and the benchmark access control sequence, SE max is the maximum value of the sum of absolute errors between the historical access control sequence and the benchmark access control sequence;

[0015] Users usually perform access control on computer terminals in a fixed order. When the access control order of a user to a computer terminal is inconsistent with historical behavior, it is possible that other people have stolen user information and accessed the computer terminal without authorization. Therefore, the absolute error between the target user's access control sequence to the target computer terminal and the benchmark access control sequence and the order risk are determined;

[0016] S23, the target computer terminal determines whether the user has exceeded the authority. If so, the over-limit risk f1 is 1, otherwise f1 is 0. As the holder of authority, the user can know the scope of his authority, and unauthorized access will try to obtain data outside the scope of authority.

[0017] S24, determine the time of the target user's access control cycle on the target computer terminal, calculate the time risk f2, let T1 and T2 represent the start and end time of the access control cycle of the target user's access control on the target computer terminal, and based on the historical data of the target user, determine the probability P1 of the target user performing access control within the time [T1, T2], let T represent the time random variable, n is the number of historical data of the target user, n1 is the number of historical data of the target user that is access controlled before time T1, n2 is the number of historical data of the target user that is access controlled after time T2, and the time risk f2 is determined based on P1, f2=P1 2 -2×P1+1;

[0018] When P1 is 0, it means that the probability of the user performing access control in this time period is 0. At this time, f2 is 1, and the risk value reaches the maximum value; when P1 is 1, it means that the probability of the user performing access control in this time period is 1. At this time, f2 is 0, and the risk value reaches the minimum value. As P1 increases, the speed at which the risk value decreases also gradually decreases. This means that the difficulty of reducing the risk value will gradually increase, which is more in line with the actual situation.

[0019] S25, let the number of times the target user performs access control on the target computer terminal in an access control cycle be N, and determine the number risk f3 based on N, N 众 is the mode of the number of times the target user performs access control on the target computer terminal in an access control cycle in the historical data, P2 is the probability that the number of times the target user performs access control on the target computer terminal reaches N in an access control cycle, let NUM represent the random variable of the number of access control times, sn1 is the number of historical data in which the target user has less access control times than N in an access control cycle;

[0020] S26, determining a first risk value F of the target user, F=f(1+f1+f2+f3).

[0021] In step S13, determining the second risk value of the target user according to the access control records of all users on each target computer terminal further includes the following steps:

[0022] Let G represent the second risk value of the target user, Gi represents the risk value of the i-th target computer terminal, represents the risk value brought by the jth access control behavior of the target user on the i-th target computer terminal, b is the number of access control behaviors of the target user on the i-th target computer terminal within a cycle; according to the identities of other users who have performed access control on the i-th target computer terminal before the j-th access control behavior of the target user on the i-th target computer terminal, the risk value is determined. When the user is hour, V i represents the number of historical data of access control operations performed by the target user on the i-th target computer terminal, V i (u) indicates that the user After that, the target user's historical data of access control operations on the i-th target computer terminal is used to assign an additional value to u to indicate that no other user has performed access control on the target user before; k is a positive number used to reduce the risk value brought by a single access control behavior.

[0023] Normally, the value will not be 0, so as to prevent the value from being 0 multiple times without increasing the risk value. At the same time, in order to reduce the risk value under normal circumstances, a positive number k is set for scaling processing, for the case of multiple access control behaviors.

[0024] In addition to the user's own access control order, there are also access control records including users on the computer terminal. According to the target user's permissions, the target user may need to complete his duties based on other users, and access control of the computer terminal will need to be performed after other users have completed their duties. The access control records of different users on the computer terminal are used to determine the second risk value of the target user.

[0025] Specifically, k is determined by the following steps:

[0026] From the access control records of all users to computer terminals, obtain the number of times the computer terminal is accessed in the abnormal access control records, and calculate the average number of times the computer terminal is accessed in all abnormal access control records ave; let V i max and V i min means V i The maximum and minimum values ​​of (u),

[0027] The average value ave is determined based on all user identities. In order to identify abnormal access control behavior in a timely manner, it is necessary to reduce it based on ave. In extreme cases, G ji ave is reduced by the ratio of the minimum and maximum values ​​of .

[0028] In step S14, judging whether the target user has an abnormality based on the first risk value and the second risk value of the target user further includes the following steps:

[0029] Obtain the access control records of all users to the computer terminal, obtain the first risk value and the second risk value data of all users, and divide the data into a training set and a test set; let the normal data be a positive example and the abnormal data be a negative example, use the training set data to train the binary classification model to distinguish positive examples from negative examples, and verify the binary classification model with the test set data; after verification, input the first risk value and the second risk value of the target user into the second classification model, and judge according to the classification result. If the output is a positive example, the target user is not abnormal, otherwise the target user is abnormal. The data of each user in a cycle can be used as data, and the normal data and abnormal data are labeled 1 and 0 respectively. The first risk value and the second risk value data are used as input, and the label is used as input to train the support vector machine, artificial neural network, convolutional neural network and other classification models, which can realize the abnormal judgment of the target user.

[0030] In another aspect of the present invention, a distributed KVM system based on national secret SVAC video coding is provided, including: a rights management module, a record storage module, a data analysis module and a KVM module, wherein the output end of the rights management module is connected to the input end of the KVM module for performing access control on the user's rights; the output end of the data analysis module is connected to the input end of the rights management model, and judges whether the target user has an abnormality based on the target user's access control record to the computer terminal. If an abnormality exists, an instruction to close the access control authority of the target user is sent to the rights management module; if no abnormality exists, the access control authority of the target user is not restricted; the output end of the KVM module is connected to the input end of the record storage module for implementing user access control on computer terminal signals, and sending each user's access control record to the computer terminal within the authority and the access control record of all users on each computer terminal to the record storage module; the output end of the record storage module is connected to the input end of the data analysis module for storing the access control records of all users and providing the data analysis module with the data required for abnormality analysis.

[0031] The KVM module also includes a network switch, a KVM seat input unit, a KVM management center system, a spliced ​​display wall and a computer terminal. The KVM seat input unit is optically or electrically connected to the corresponding computer terminal. The KVM seat input units are optically or electrically connected to the network switch. The network switch is electrically connected to the KVM management center system. The KVM management center system consists of a KVM seat output unit, a display, a keyboard and a mouse. The KVM seat output units are electrically connected to the network switch, the KVM seat output units are electrically connected to the display, the KVM seat output units are electrically connected to the keyboard and mouse, and the KVM seat output units are electrically connected to the spliced ​​display wall.

[0032] The KVM seat input unit encrypts the audio, video and access control data through the SVAC2 national secret coding protocol and transmits them to the network switch. The KVM seat output unit decrypts, decodes and displays the audio, video and access control data signals sent by the network switch. The network switch is internally provided with an ASCI processing chip, which encodes and packages the collected audio and video data signals and sends them to the KVM seat output unit. The keyboard and mouse are used for access control signal display and switching of the KVM seat input unit, and the mouse is also used for roaming hotkey switching between KVM seat input units.

[0033] The data analysis module also includes a user risk value determination unit, a computer terminal risk value determination unit and an abnormality analysis unit. The user risk value determination unit determines a first risk value of the target user according to the target user's access control order, access control time and access control times to the computer terminal. The computer terminal risk value determination unit determines a second risk value of the target user according to the access control record data of all users including the target user on the computer terminal. The abnormality analysis unit determines abnormal situations based on the first risk value and the second risk value of the target user and generates instructions.

[0034] The user risk value determination unit determines the order risk based on the absolute error between the access control sequence of the target user to the target computer terminal and the benchmark access control sequence, determines the over-limit risk based on whether the user has exceeded the authority, determines the time risk based on the time of the access control cycle of the target user's access control to the target computer terminal, determines the number risk based on the number of times the target user accesses the target computer terminal within an access control cycle, and determines the first risk value of the target user based on the order risk, over-limit risk, time risk and number risk.

[0035] Compared with the prior art, the beneficial effects achieved by the present invention are: preventing unauthorized access and illegal monitoring of KVM data streams through the national secret video encoding SVAC2 method, transmitting the data to the KVM management center system through the network switch network, and performing video pre-monitoring and visual access control switching management on all nodes in the network through the KVM seat output node of the KVM management center system. Access control management can be performed on the signals of all nodes by using a set of mouse and keyboard through hot key switching, and point-to-multiple visual switching access control is realized through distributed networking. Remote access control can be realized by using the KVM access control Web client anywhere in the network, and transmission access control of KVM encrypted data streams is realized, reducing the risk of KVM data during transmission; the first risk value and the second risk value are determined through the user's access control behavior, and abnormal analysis is performed on the user to reduce the security risks brought to KVM data by the user. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0037] Figure 1 It is a schematic diagram of the structure of a distributed KVM system based on national secret SVAC video coding according to an embodiment of the present invention;

[0038] Figure 2 It is a specific structural diagram of the KVM module of an embodiment of the present invention. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] In the embodiments of the present invention, please refer to Figure 1 , providing a distributed KVM system based on the national secret SVAC video encoding, including:

[0041] A rights management module, a record storage module, a data analysis module and a KVM module, wherein the output end of the rights management module is connected to the input end of the KVM module for performing access control on user rights; the output end of the data analysis module is connected to the input end of the rights management model, and judges whether the target user has an abnormality based on the target user's access control record to the computer terminal. If an abnormality exists, an instruction to close the target user's access control authority is sent to the rights management module; if no abnormality exists, the target user's access control authority is not restricted; the output end of the KVM module is connected to the input end of the record storage module for implementing user access control on computer terminal signals, and sending each user's access control record to the computer terminal within the authority and the access control record of all users on each computer terminal to the record storage module; the output end of the record storage module is connected to the input end of the data analysis module for storing the access control records of all users and providing the data required for abnormality analysis to the data analysis module.

[0042] The KVM module also includes a network switch, a KVM seat input unit, a KVM management center system, a spliced ​​display wall and a computer terminal. The KVM seat input unit is optically or electrically connected to the corresponding computer terminal. The KVM seat input units are optically or electrically connected to the network switch. The network switch is electrically connected to the KVM management center system. The KVM management center system consists of a KVM seat output unit, a display, a keyboard and a mouse. The KVM seat output units are electrically connected to the network switch, the KVM seat output units are electrically connected to the display, the KVM seat output units are electrically connected to the keyboard and mouse, and the KVM seat output units are electrically connected to the spliced ​​display wall.

[0043] The KVM seat input unit encrypts the audio, video and access control data through the SVAC2 national secret coding protocol and transmits them to the network switch. The KVM seat output unit decrypts, decodes and displays the audio, video and access control data signals sent by the network switch. The network switch is internally provided with an ASCI processing chip, which encodes and packages the collected audio and video data signals and sends them to the KVM seat output unit. The keyboard and mouse are used for access control signal display and switching of the KVM seat input unit, and the mouse is also used for roaming hotkey switching between KVM seat input units.

[0044] The data analysis module also includes a user risk value determination unit, a computer terminal risk value determination unit and an abnormality analysis unit. The user risk value determination unit determines a first risk value of the target user according to the target user's access control order, access control time and access control times to the computer terminal. The computer terminal risk value determination unit determines a second risk value of the target user according to the access control record data of all users including the target user on the computer terminal. The abnormality analysis unit determines abnormal situations based on the first risk value and the second risk value of the target user and generates instructions.

[0045] The user risk value determination unit determines the order risk based on the absolute error between the access control sequence of the target user to the target computer terminal and the benchmark access control sequence, determines the over-limit risk based on whether the user has exceeded the authority, determines the time risk based on the time of the access control cycle of the target user's access control to the target computer terminal, determines the number risk based on the number of times the target user accesses the target computer terminal within an access control cycle, and determines the first risk value of the target user based on the order risk, over-limit risk, time risk and number risk.

[0046] In an embodiment of the present invention, a distributed KVM method based on national secret SVAC video coding is provided, including:

[0047] S11, obtaining the target user's access control record to the computer terminal;

[0048] S12, according to the target user's access control record to the target computer terminal, the target computer terminal is a computer terminal for which the target user holds access control authority, determining a first risk value of the target user, including steps S21 to S26:

[0049] S21, within an access control cycle, obtaining the target user's access control sequence to the target computer terminal; starting from the first computer terminal accessed by the target user, ignoring the computer terminals that are repeatedly accessed, and when the target user has access control actions on all target computer terminals, obtaining the target user's access control sequence to the target computer terminal in chronological order;

[0050] S22, the target user's access control sequence to the target computer terminal is represented by the index number of the target computer terminal. In the historical data of the target user, the number of occurrences of different access control sequences of the target user to the target computer terminal is determined, and the mode of the number of occurrences is found. The access control sequence corresponding to the mode is the benchmark access control sequence. The absolute error and SE between the target user's access control sequence to the target computer terminal and the benchmark access control sequence are calculated. d1 iis the sequence position of the i-th target computer terminal in the target user's access control sequence to the target computer terminal, d2 i The position of the i-th target computer terminal in the benchmark access control sequence, m is the number of target computer terminals; the order risk f is determined based on the absolute error and SE, SE min is the minimum value of the absolute error sum between the historical access control sequence and the benchmark access control sequence, SE max is the maximum value of the sum of absolute errors between the historical access control sequence and the benchmark access control sequence;

[0051] For the five computer terminals numbered 1, 2, 3, 4, and 5, if the access control sequence corresponding to the mode of access control times in the target user's historical data is 12345, and the access control sequence of the current target user is 13245, the absolute error and SE are: 0+1+1+0+0=2; the access control sequence corresponding to the mode is the benchmark access control sequence, so SE min In most cases, it is 0, and the order risk f is:

[0052] S23, the target computer terminal determines whether the user has exceeded the authority. If so, the over-limit risk f1 is 1, otherwise f1 is 0;

[0053] S24, determine the time of the access control cycle of the target user's access control on the target computer terminal, calculate the time risk f2, let T1 and T2 represent the start and end time of the access control cycle of the target user's access control on the target computer terminal, and based on the historical data of the target user, determine the probability P1 of the target user performing access control within the time [T1, T2], let T represent the time random variable, n is the number of historical data of the target user, n1 is the number of historical data of the target user that is access controlled before time T1, n2 is the number of historical data of the target user that is access controlled after time T2, and the time risk f2 is determined based on P1, f2=P1 2 -2×P1+1;

[0054] S25, let the number of times the target user performs access control on the target computer terminal in an access control cycle be N, and determine the number risk f3 based on N, N 众 is the mode of the number of times the target user performs access control on the target computer terminal in an access control cycle in the historical data, P2 is the probability that the number of times the target user performs access control on the target computer terminal reaches N in an access control cycle, let NUM represent the random variable of the number of access control times, sn1 is the number of historical data in which the target user has less access control times than N in an access control cycle;

[0055] S26, determining a first risk value F of the target user, F=f(1+f1+f2+f3).

[0056] S13, determining the second risk value of the target user based on the access control records of all users on each target computer terminal:

[0057] Let G represent the second risk value of the target user, G i represents the risk value of the i-th target computer terminal, represents the risk value brought by the jth access control behavior of the target user on the i-th target computer terminal, b is the number of access control behaviors of the target user on the i-th target computer terminal within a cycle; according to the identities of other users who have performed access control on the i-th target computer terminal before the j-th access control behavior of the target user on the i-th target computer terminal, the risk value is determined. When the user is hour, V i represents the number of historical data of access control operations performed by the target user on the i-th target computer terminal, V i (u) indicates that the user After that, the target user's historical data of access control operations on the i-th target computer terminal is used to assign an additional value to u to indicate that no other user has performed access control on the target user before; k is a positive number used to reduce the risk value brought by a single access control behavior.

[0058] k is determined by the following steps:

[0059] From the access control records of all users to computer terminals, obtain the number of times the computer terminal is accessed in the abnormal access control records, and calculate the average number of times the computer terminal is accessed in all abnormal access control records ave; let V i max and V i min means V i The maximum and minimum values ​​of (u),

[0060] S14, judging whether the target user has an abnormality based on the first risk value and the second risk value of the target user:

[0061] Obtain access control records of all users to computer terminals, obtain the first risk value and second risk value data of all users, and divide the data into a training set and a test set; let normal data be positive examples and abnormal data be negative examples, use the training set data to train a binary classification model to distinguish positive examples from negative examples, and use the test set data to verify the binary classification model; after verification, input the first risk value and the second risk value of the target user into the binary classification model, and make a judgment based on the classification result. If the output is a positive example, the target user is not abnormal, otherwise the target user is abnormal;

[0062] If there is an abnormality, the target user's access control authority to the target computer terminal is closed, and the target user's identity is authenticated. If the target user passes the identity authentication, the authority is opened again, and the first risk value and the second risk value at this time are marked as normal data. If the identity authentication is not passed, the first risk value and the second risk value at this time are marked as abnormal data;

[0063] If there is no abnormality, the target user's access control authority to the target computer terminal will not be restricted.

[0064] S15, the target user controls the access to the target computer terminal through his own authority, and performs SVAC2 encryption encoding on the audio and video data of the computer terminal. Based on the received audio and video data, the target user performs access control management on the signals of all computer terminals through a set of keyboard and mouse hotkey switches.

[0065] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants 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 other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0066] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A distributed KVM method based on national secret SVAC video coding, characterized in that: The following steps are involved: S11, obtaining the target user's access control record to the computer terminal; S12, determining a first risk value of the target user according to the target user's access control record to the target computer terminal; the target computer terminal is a computer terminal to which the target user holds access control authority; including steps S21 to S26: S21, within an access control cycle, obtaining the target user's access control sequence to the target computer terminal; starting from the first computer terminal accessed by the target user, ignoring the computer terminals that are repeatedly accessed, and when the target user has access control actions on all target computer terminals, obtaining the target user's access control sequence to the target computer terminal in chronological order; S22, the target user's access control sequence to the target computer terminal is represented by the index number of the target computer terminal. In the historical data of the target user, the number of occurrences of different access control sequences of the target user to the target computer terminal is determined, and the mode of the number of occurrences is found. The access control sequence corresponding to the mode is the benchmark access control sequence. The absolute error and SE between the target user's access control sequence to the target computer terminal and the benchmark access control sequence are calculated. d1 i is the sequence position of the i-th target computer terminal in the target user's access control sequence to the target computer terminal, d2 i The position of the i-th target computer terminal in the benchmark access control sequence, m is the number of target computer terminals; the order risk f is determined based on the absolute error and SE, SE min is the minimum value of the absolute error sum between the historical access control sequence and the benchmark access control sequence, SE max is the maximum value of the sum of absolute errors between the historical access control sequence and the benchmark access control sequence; S23, the target computer terminal determines whether the user has exceeded the authority. If so, the over-limit risk f1 is 1, otherwise f1 is 0; S24, determine the time of the target user's access control cycle on the target computer terminal, calculate the time risk f2, let T1 and T2 represent the start and end time of the access control cycle of the target user's access control on the target computer terminal, and based on the historical data of the target user, determine the probability P1 of the target user performing access control within the time [T1, T2], let T represent the time random variable, n is the number of historical data of the target user, n1 is the number of historical data of the target user that is access controlled before time T1, n2 is the number of historical data of the target user that is access controlled after time T2, and the time risk f2 is determined based on P1, f2=P1 2 -2×P1+1; S25, let the number of times the target user performs access control on the target computer terminal in an access control cycle be N, and determine the number risk f3 based on N, N 众 is the mode of the number of times the target user performs access control on the target computer terminal in an access control cycle in the historical data, P2 is the probability that the number of times the target user performs access control on the target computer terminal reaches N in an access control cycle, let NUM represent the random variable of the number of access control times, sn1 is the number of historical data in which the target user has less access control times than N in an access control cycle; S26, determining a first risk value F of the target user, F=f(1+f1+f2+f3); S13, determining a second risk value of the target user according to the access control records of all users on each target computer terminal; S14, judging whether the target user has abnormality based on the first risk value and the second risk value of the target user, If there is an abnormality, the target user's access control authority to the target computer terminal is closed, and the target user's identity is authenticated. If the target user passes the identity authentication, the authority is opened again, and the first risk value and the second risk value at this time are marked as normal data. If the identity authentication is not passed, the first risk value and the second risk value at this time are marked as abnormal data; If there is no abnormality, the target user's access control authority to the target computer terminal will not be restricted; S15, the target user controls the access to the target computer terminal through his own authority, and performs SVAC encryption encoding on the audio and video data of the computer terminal. The target user performs access control management on the signals of all computer terminals through a set of keyboard and mouse hotkey switches based on the received audio and video data.

2. The distributed KVM method based on national secret SVAC video coding according to claim 1 is characterized in that: In step S13, determining the second risk value of the target user according to the access control records of all users on each target computer terminal further includes the following steps: Let G represent the second risk value of the target user, G i represents the risk value of the i-th target computer terminal, represents the risk value brought by the jth access control behavior of the target user on the i-th target computer terminal, b is the number of access control behaviors of the target user on the i-th target computer terminal within a cycle; according to the identities of other users who have performed access control on the i-th target computer terminal before the j-th access control behavior of the target user on the i-th target computer terminal, the risk value is determined. When the user is hour, V i represents the number of historical data of access control operations performed by the target user on the i-th target computer terminal, V i (u) indicates that the user After that, the target user's historical data of access control operations on the i-th target computer terminal is used to assign an additional value to u to indicate that no other user has performed access control on the target user before; k is a positive number used to reduce the risk value brought by a single access control behavior.

3. The distributed KVM method based on national secret SVAC video coding according to claim 2 is characterized in that: The positive number k is determined by the following steps: From the access control records of all users to computer terminals, obtain the number of times the computer terminal is accessed in the abnormal access control records, and calculate the average number of times the computer terminal is accessed in all abnormal access control records ave; let V i max and V i min means V i The maximum and minimum values ​​of (u), 4. The distributed KVM method based on national secret SVAC video coding according to claim 3 is characterized in that: In step S14, judging whether the target user has an abnormality based on the first risk value and the second risk value of the target user further includes the following steps: Obtain access control records of all users to computer terminals, obtain the first risk value and second risk value data of all users, and divide the data into a training set and a test set; let normal data be positive examples and abnormal data be negative examples, use the training set data to train a binary classification model to distinguish positive examples from negative examples, and verify the binary classification model with the test set data; after verification, input the first risk value and the second risk value of the target user into the binary classification model, and make a judgment based on the classification result. If the output is a positive example, the target user does not have an abnormality, otherwise the target user does have an abnormality.

5. A distributed KVM system based on national secret SVAC video coding, using a distributed KVM method based on national secret SVAC video coding as described in any one of claims 1 to 4, characterized in that: include: A rights management module, a record storage module, a data analysis module and a KVM module, wherein the output end of the rights management module is connected to the input end of the KVM module for performing access control on user rights; the output end of the data analysis module is connected to the input end of the rights management model, and judges whether the target user has an abnormality based on the target user's access control record to the computer terminal. If an abnormality exists, an instruction to close the target user's access control authority is sent to the rights management module; if no abnormality exists, the target user's access control authority is not restricted; the output end of the KVM module is connected to the input end of the record storage module for implementing user access control on computer terminal signals, and sending each user's access control record to the computer terminal within the authority and the access control record of all users on each computer terminal to the record storage module; the output end of the record storage module is connected to the input end of the data analysis module for storing the access control records of all users and providing the data required for abnormality analysis to the data analysis module.

6. The distributed KVM system based on national secret SVAC video coding according to claim 5 is characterized in that: The KVM module also includes a network switch, a KVM seat input unit, a KVM management center system, a spliced ​​display wall and a computer terminal. The KVM seat input unit is optically or electrically connected to the corresponding computer terminal. The KVM seat input units are optically or electrically connected to the network switch. The network switch is electrically connected to the KVM management center system. The KVM management center system consists of a KVM seat output unit, a display, a keyboard and a mouse. The KVM seat output units are electrically connected to the network switch, the KVM seat output units are electrically connected to the display, the KVM seat output units are electrically connected to the keyboard and mouse, and the KVM seat output units are electrically connected to the spliced ​​display wall.

7. The distributed KVM system based on national secret SVAC video coding according to claim 6 is characterized in that: The KVM seat input unit encrypts the audio, video and access control data through the SVAC national secret coding protocol and transmits them to the network switch. The KVM seat output unit decrypts, decodes and displays the audio, video and access control data signals sent by the network switch. The network switch is equipped with an ASCI processing chip to encode and package the collected audio and video data signals and send them to the KVM seat output unit. The keyboard and mouse are used for access control signal display and switching of the KVM seat input unit, and the mouse is also used for roaming hotkey switching between KVM seat input units.

8. The distributed KVM system based on national secret SVAC video coding according to claim 5 is characterized in that: The data analysis module further includes a user risk value determination unit, a computer terminal risk value determination unit and an abnormality analysis unit. The user risk value determination unit determines a first risk value of the target user according to the target user's access control order, access control time and access control times to the computer terminal. The computer terminal risk value determination unit determines a second risk value of the target user according to access control record data of all users including the target user on the computer terminal. The abnormality analysis unit determines an abnormal situation based on a first risk value and a second risk value of the target user, and generates an instruction.

9. The distributed KVM system based on national secret SVAC video coding according to claim 8 is characterized in that: The user risk value determination unit determines the order risk based on the absolute error between the access control sequence of the target user to the target computer terminal and the benchmark access control sequence, determines the over-limit risk based on whether the user has exceeded the authority, determines the time risk based on the time of the access control cycle of the target user's access control to the target computer terminal, determines the number risk based on the number of times the target user accesses the target computer terminal within an access control cycle, and determines the first risk value of the target user based on the order risk, over-limit risk, time risk and number risk.

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