阅读说明：本技术 一种用于椭圆曲线密码的倍点运算方法及系统 (Doubling point operation method and system for elliptic curve password ) 是由 彭金辉 张朝阳 雷宗华 廖正赟 刘武忠 卫志刚 于 2020-03-26 设计创作，主要内容包括：本发明提出一种用于椭圆曲线密码的倍点运算方法,包括：根据椭圆曲线阶的位数N比特计算椭圆曲线上点(x,y)占用空间；将椭圆曲线阶的位数N依据V比特划分为(N+V-1)/V份单元,计算椭圆曲线上点(x,y)的数量和查找表的大小；根据查找表的大小和设备内存大小计算V的最大值；计算<Image he="133" wi="93" file="DDA0002427560710000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>并依次计算k*2<Sup>iV</Sup>G,其中,<Image he="111" wi="363" file="DDA0002427560710000012.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>k∈[1,2<Sup>v</Sup>-1],并根据计算的结果生成划分的各个单元的查找表；计算N％V,并计算<Image he="95" wi="305" file="DDA0002427560710000013.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>其中,k∈[1,2<Sup>N％V</Sup>-1]；依据K的取值不同依次从划分的各个单元的查找表中获取相应计算结果并进行点加运算获得椭圆曲线基点G的K倍点[K]G的点乘结果；本发明根据设备资源可动态构造查找表、提高倍点运算速度。(The invention provides a point doubling operation method for elliptic curve cryptography, which comprises the following steps: calculating the occupied space of points (x, y) on the elliptic curve according to the digit N bits of the elliptic curve order; dividing the digit N of the elliptic curve order into (N + V-1)/V units according to V bits, and calculating the number of points (x, y) on the elliptic curve and the size of a lookup table; calculating the maximum value of V according to the size of the lookup table and the size of the equipment memory; computing And sequentially calculating k 2 iV G, wherein, k∈[1，2 v ‑1]generating a lookup table of each divided unit according to the calculation result; calculate N% V, and calculate Wherein, k ∈ [1,2 ] N％V ‑1](ii) a According to different values of K, obtaining corresponding calculation results from the lookup tables of the divided units in sequence and carrying out point addition operation to obtain K times of points [ K ] of the elliptic curve base point G]The dot product result of G; the invention can dynamically construct a lookup table according to equipment resources and improve the speed of point doubling operation.)

1. A method for point doubling operation of elliptic curve cryptography, the method comprising: a parameter determining process, a lookup table generating process and a point doubling operation process;

the parameter determination process comprises the following steps:

calculating the occupied space of a point (x, y) on the elliptic curve according to the digit N bits of the elliptic curve order;

setting V bits, dividing the digit N of the elliptic curve order into (N + V-1)/V units according to the V bits, and calculating the number of points (x, y) on the elliptic curve;

calculating the size of a lookup table according to the number of points (x, y) on the elliptic curve;

calculating the maximum value of V according to the size of the lookup table and the size of the equipment memory;

and a lookup table generation process:

computingFor each k ∈ [1,2 ]^V-1]Sequentially calculating k x 2^iVG, wherein,g is a base point; generating a lookup table of each divided unit according to a calculation result, and storing the lookup table in the equipment memory;

calculate N% V, and calculateWherein, k ∈ [1,2 ]^N％V-1]；

And (3) a point doubling operation process:

and sequentially obtaining corresponding calculation results from the lookup tables of the divided units according to different values of K, and performing point addition operation to obtain a point multiplication result of a K times point [ K ] G of the elliptic curve base point G.

2. The point doubling operation method according to claim 1, wherein the number of points (x, y) on the elliptic curve is calculated by:

calculating the size of the lookup table according to the number of the points (x, y) on the elliptic curve specifically comprises:

calculating the maximum value of V according to the size of the lookup table and the size of the equipment memory specifically comprises the following steps: order to Calculating the maximum value of V; wherein S is a device memory and has a unit of bytes.

3. The method of claim 1 or 2, wherein the space occupied by the points (x, y) on the elliptic curve is N/4 bytes.

4. The point arithmetic method according to claim 1, characterized in that the point arithmetic method further comprises a flag setting process of:

setting a preset threshold value of V as a mark for judging whether to use a lookup table to carry out point doubling operation, and if the V is not less than the preset threshold value, using the lookup table to carry out the point doubling operation; otherwise, using a non-lookup table method to perform the multiple point operation.

5. The doubling point operation method according to claim 4, wherein in the flag setting process, the threshold value of V is set in advance by comparing the operation amounts of the doubling point operation using the lookup table and the doubling point operation using the non-lookup table method.

6. A system for point doubling operations for elliptic curve cryptography, said system comprising: the device comprises a parameter determining unit, a lookup table generating unit and a point doubling operation unit;

the parameter determining unit comprises a first calculating module and a dividing module;

the dividing module is used for dividing the digit N of the elliptic curve order into (N + V-1)/V units according to V bits;

the calculation module is used for calculating the occupied space of points (x, y) on the elliptic curve according to the digit N bits of the elliptic curve order; and also for calculating the number of points (x, y) on the elliptic curve; and the device is used for calculating the size of a lookup table according to the number of points (x, y) on the elliptic curve and calculating the maximum value of V according to the size of the lookup table and the size of a device memory;

the lookup table generating unit comprises a second calculating module and a constructing module;

the second calculation module is used for calculatingFor each k ∈ [1,2 ]^V-1]Sequentially calculating k x 2^iVG, wherein,g is a base point; generating a lookup table of each divided unit according to a calculation result, and storing the lookup table in the equipment memory; calculate N% V, and calculateWherein, k ∈ [1,2 ]^N％V-1]；

The construction module is used for constructing and generating a lookup table of each divided unit according to a calculation result and storing the lookup table in the equipment memory;

the point doubling operation unit comprises a result acquisition module and a point addition module;

the result acquisition module is used for sequentially acquiring corresponding calculation results from the lookup tables of the divided units according to different values of K;

and the point addition module is used for performing point addition operation on each obtained calculation result to obtain a point multiplication result of a K-time point [ K ] G of the elliptic curve base point G.

7. The point doubling operation system according to claim 6, wherein the calculating module calculates the number of points (x, y) on the elliptic curve by:

the calculation module calculates the size of the lookup table according to the number of the points (x, y) on the elliptic curve, specifically:

the calculation module calculates the maximum value of V according to the size of the lookup table and the size of the device memory, specifically: order toCalculating the maximum value of V; wherein S is a device memory and has a unit of bytes.

8. The point doubling system according to claim 6 or 7, wherein the occupation space of the points (x, y) on the elliptic curve is N/4 bytes.

9. The point doubling operation system according to claim 6, further comprising a marking unit, the marking unit including a setting module and a judging module;

the setting module is used for setting the threshold value of the preset V as a mark for judging whether to use the lookup table to carry out point doubling operation;

the judging module is used for judging according to the set threshold value of the V of the point doubling operation, and if the V is not less than the preset threshold value, the point doubling operation is carried out by using a lookup table; otherwise, using a non-lookup table method to perform the multiple point operation.

10. The doubling operation system according to claim 9, wherein the marking unit further comprises a comparison module for setting a threshold value of V in advance by comparing operation amounts of the doubling operation using the lookup table and the doubling operation using the non-lookup table method.

Technical Field

The invention relates to the technical field of passwords, in particular to a point doubling operation method and system for elliptic curve passwords.

Background

An Elliptic Curve Cryptogram (ECC) belongs to an asymmetric cryptosystem, and has the characteristics of short key length, high encryption and decryption speed, low requirement on a computing environment, low requirement on bandwidth when communication is needed and the like, so that the ECC is widely applied to the field of commercial cryptograms in recent years. The SM2 cipher is also an asymmetric cryptosystem, which is an ECC-based asymmetric cryptosystem.

The SM2 elliptic curve algorithm comprises an SM2 encryption/decryption cryptographic algorithm and an SM2 signature/signature cryptographic algorithm, and in the SM2 signature, signature and encryption algorithm process, a multiple point of a fixed point G on an ECC elliptic curve needs to be calculated, namely [ k ] G is calculated, wherein k is a random number, and multiple point operation is a key step and is a step which consumes the longest time. At present, the arithmetic of the multiple point operation mainly adopts a binary expansion method, an addition and subtraction method, a sliding window method, a table look-up method and the like, wherein the calculation speed is fastest by the table look-up method, but the table look-up method has the defect of large occupied resources (such as a memory, a flash memory and the like), the realization can not dynamically adapt to various equipment resources, the same arithmetic can normally and effectively work on a PC, but can not normally work in the equipment with limited resources.

Therefore, how to dynamically construct a lookup table according to device resources and improve the speed of the point doubling operation is a problem which needs to be solved urgently at present.

Disclosure of Invention

In view of the above problems, it is desirable to provide a method and system for performing a multiple point operation for elliptic curve cryptography, which can dynamically construct a lookup table according to device resources and increase the speed of the multiple point operation.

The invention provides a point doubling operation method for elliptic curve cryptography, which comprises the following steps: a parameter determining process, a lookup table generating process and a point doubling operation process;

the parameter determination process comprises the following steps:

calculating the occupied space of a point (x, y) on the elliptic curve according to the digit N bits of the elliptic curve order;

setting V bits, dividing the digit N of the elliptic curve order into (N + V-1)/V units according to the V bits, and calculating the number of points (x, y) on the elliptic curve;

calculating the size of a lookup table according to the number of points (x, y) on the elliptic curve;

calculating the maximum value of V according to the size of the lookup table and the size of the equipment memory;

and a lookup table generation process:

computingFor each k ∈ [1,2 ]^V-1]Sequentially calculating k x 2^iVG, wherein, g is a base point; generating a lookup table of each divided unit according to a calculation result, and storing the lookup table in the equipment memory;

calculate N% V, and calculateWherein, k ∈ [1,2 ]^N％V-1](ii) a And (3) a point doubling operation process:

and sequentially obtaining corresponding calculation results from the lookup tables of the divided units according to different values of K, and performing point addition operation to obtain a point multiplication result of a K times point [ K ] G of the elliptic curve base point G.

Further, the number of points (x, y) on the elliptic curve is specifically calculated as follows:

calculating the size of the lookup table according to the number of the points (x, y) on the elliptic curve specifically comprises:

calculating the maximum value of V according to the size of the lookup table and the size of the equipment memory specifically comprises the following steps: order toCalculating the maximum value of V; wherein S is a device memory and has a unit of bytes.

Further, the occupied space of the point (x, y) on the elliptic curve is N/4 bytes.

Further, the point doubling operation method further comprises a mark setting process:

setting a preset threshold value of V as a mark for judging whether to use a lookup table to carry out point doubling operation, and if the V is not less than the preset threshold value, using the lookup table to carry out the point doubling operation; otherwise, using a non-lookup table method to perform the multiple point operation.

Further, in the flag setting process, the threshold value of V is set in advance by comparing the operation amounts of the double-point operation using the lookup table and the double-point operation using the non-lookup table method.

The second aspect of the present invention further provides a point doubling operation system for elliptic curve cryptography, comprising: the device comprises a parameter determining unit, a lookup table generating unit and a point doubling operation unit;

the parameter determining unit comprises a first calculating module and a dividing module;

the dividing module is used for dividing the digit N of the elliptic curve order into (N + V-1)/V units according to V bits;

the calculation module is used for calculating the occupied space of points (x, y) on the elliptic curve to be N/4 bytes according to the digit N bits of the elliptic curve order; and also for calculating the number of points (x, y) on the elliptic curve; and the device is used for calculating the size of a lookup table according to the number of points (x, y) on the elliptic curve and calculating the maximum value of V according to the size of the lookup table and the size of a device memory;

the lookup table generating unit comprises a second calculating module and a constructing module;

the second calculation module is used for calculatingFor each k ∈ [1,2 ]^V-1]Sequentially calculating k x 2^iVG, wherein,g is a base point; generating a lookup table of each divided unit according to a calculation result, and storing the lookup table in the equipment memory; calculate N% V, and calculateWherein, k ∈ [1,2 ]^N％V-1]；

The construction module is used for constructing and generating a lookup table of each divided unit according to a calculation result and storing the lookup table in the equipment memory;

the point doubling operation unit comprises a result acquisition module and a point addition module;

the result acquisition module is used for sequentially acquiring corresponding calculation results from the lookup tables of the divided units according to different values of K;

and the point addition module is used for performing point addition operation on each obtained calculation result to obtain a point multiplication result of a K-time point [ K ] G of the elliptic curve base point G.

Further, the calculating module calculates the number of the points (x, y) on the elliptic curve specifically as follows:

the calculation module calculates the size of the lookup table according to the number of the points (x, y) on the elliptic curve, specifically:

the calculation module calculates the maximum value of V according to the size of the lookup table and the size of the device memory, specifically: order toCalculating the maximum value of V; wherein S is a device memory and has a unit of bytes.

Further, the occupied space of the point (x, y) on the elliptic curve is N/4 bytes.

Furthermore, the point doubling operation system also comprises a marking unit, wherein the marking unit comprises a setting module and a judging module;

the setting module is used for setting the threshold value of the preset V as a mark for judging whether to use the lookup table to carry out point doubling operation;

the judging module is used for judging according to the set threshold value of the V of the point doubling operation, and if the V is not less than the preset threshold value, the point doubling operation is carried out by using a lookup table; otherwise, using a non-lookup table method to perform the multiple point operation.

Further, the marking unit further includes a comparison module for setting the threshold value of V in advance by comparing the operation amounts of the double-point operation using the lookup table and the double-point operation using the non-lookup table method.

The invention has prominent substantive characteristics and remarkable progress, in particular to the following steps:

(1) calculating the maximum value of V bits according to the number N of digits of the elliptic curve steps, the number of the points (x, y) on the elliptic curve, the size parameters of the lookup table and the size of the equipment memory; then, the calculation of the lookup table of each unit is carried out through the calculated size of the lookup table, the equipment resources and the calculated size of the V bit, so that the lookup table corresponding to the equipment resources is constructed and generated, different equipment resources can be dynamically adapted, and the method has the characteristic of strong adaptability;

(2) in the process of carrying out the point doubling operation, according to the K value, a corresponding calculation result can be quickly obtained through constructing a generated lookup table to carry out the point addition operation, so that the calculation speed of the point doubling operation is improved, and the point doubling operation can be carried out by using a lookup table method under the condition of less equipment resources without being limited by the equipment resources;

(3) whether the multiple point operation is carried out by using the lookup table is judged by setting the multiple point operation mark, so that the flexible application of the system is ensured, and the operation speed is improved.

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

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a flow chart of a method for performing a multiple operation on elliptic curve cryptography according to the present invention;

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

As shown in fig. 1, a first aspect of the present invention provides a method for performing a double operation on an elliptic curve cipher, the method comprising: a parameter determining process, a lookup table generating process and a point doubling operation process;

the parameter determination process comprises the following steps:

calculating the occupied space of a point (x, y) on the elliptic curve according to the digit N bits of the elliptic curve order;

setting V bits, dividing the digit N of the elliptic curve order into (N + V-1)/V units according to the V bits, and calculating the number of points (x, y) on the elliptic curve;

calculating the size of a lookup table according to the number of points (x, y) on the elliptic curve;

calculating the maximum value of V according to the size of the lookup table and the size of the equipment memory;

and a lookup table generation process:

computingFor each k ∈ [1,2 ]^V-1]Sequentially calculating k x 2^iVG, wherein, g is a base point; generating a lookup table of each divided unit according to a calculation result, and storing the lookup table in the equipment memory;

calculate N% V, and calculateWherein, k ∈ [1,2 ]^N％V-1]；

And (3) a point doubling operation process:

and sequentially obtaining corresponding calculation results from the lookup tables of the divided units according to different values of K, and performing point addition operation to obtain a point multiplication result of a K times point [ K ] G of the elliptic curve base point G.

In particular, the elliptic curveThe number of points (x, y) on the line is specifically calculated as:

calculating the size of the lookup table according to the number of the points (x, y) on the elliptic curve specifically comprises:

calculating the maximum value of V according to the size of the lookup table and the size of the equipment memory specifically comprises the following steps: order toCalculating the maximum value of V; wherein S is a device memory and has a unit of bytes.

Specifically, if the value of N% V is 0; in the parameter determining process, dividing the digit N of the elliptic curve order into N/V units according to V bits, wherein the number of points (x, y) on the elliptic curve is specifically calculated as follows:

calculating the size of the lookup table according to the number of the points (x, y) on the elliptic curve specifically comprises:

calculating the maximum value of V according to the size of the lookup table and the size of the equipment memory specifically comprises the following steps: order toCalculating the maximum value of V; wherein S is a device memory and has a unit of bytes.

It should be noted that, in the following description,the results represented are integers, specifically rounded down, e.g.,then 36.

In a specific embodiment, if the number N of elliptic curve steps is 256 bits (N is set to be an integer multiple of 8), and the device memory is 512 bytes, the occupied space of the point (x, y) on the elliptic curve is 256/4-64 bytes;

first, the number of points (x, y) on the elliptic curve is calculated as:

secondly, the size of the calculation lookup table is specifically as follows:

order toObtaining the maximum value of V as 8 bits;

dividing the elliptic curve step with the number of bits N of 256 into 32 units according to 8 bits, which is equivalent to constructing a lookup table for generating 32 units and occupies 512KB in total;

calculate in turn

KG＝k*2^iVG＝k1*2⁰G+k2*2⁸G+k3*2¹⁶G+k4*2²⁴G+......+k32*2²⁴⁸And G, equivalently, 32 point addition operations are required, and the calculation results of 32 points are already in 32 lookup tables generated by construction, and only the specific value of K in each lookup table needs to be known, so that the corresponding calculation result can be quickly searched according to the value of K, and the calculation speed is greatly improved.

In a specific embodiment, if the value of N% V is not 0, for example, the number N of bits of the elliptic curve step is 256, and the method is divided into 37 units according to 7 bits, which corresponds to constructing a lookup table for generating 37 units, where the first 36 units are divided according to 7 bits, and the highest bit, that is, the 37 th unit, includes 4 bits:

calculate in turn

KG＝k*2^ivG＝k1*2⁰G+k2*2⁸G+k3*2¹⁶G+k4*2²⁴G+......+k36*²⁴⁵G+k37*²⁵²G, which is equivalent to performing 37 dot addition operations, wherein the value range of k1 to k36 is [1,2 ]⁷-1]K37 is in the range of [1,2 ]⁴-1]。

The lookup table generated by the construction may be constructed in advance and preset in the device, or may be dynamically constructed when the device is initialized.

In practical application, an equipment end firstly calls an initialization interface and transmits parameters such as ECC elliptic curve parameters and equipment resources; the initialization function is responsible for calculating according to the parameters and constructing a point-doubling operation lookup table of the fixed point G; and then, when the multiple point operation interface is called, the lookup table is used for accelerating the multiple point operation.

It can be understood that if the number N of the elliptic curve steps is exactly divided into an integer number of units according to V bits, and each unit has V bits, the value of N% V is 0; if the number of bits N of the elliptic curve order cannot be completely divided when divided according to V bits, the number of the highest bit positions is less than V bits, the value of N% V is not 0, and an integer part and a remainder part exist. (2) is involved in the calculation^V-1) is that no look-up table is needed considering the lowest order bits, although a design method without subtracting 1 may be used in the actual design process.

Specifically, the multiple point operation method further includes a mark setting process:

setting a preset threshold value of V as a mark for judging whether to use a lookup table to carry out point doubling operation, and if the V is not less than the preset threshold value, using the lookup table to carry out the point doubling operation; otherwise, using a non-lookup table method to perform the multiple point operation.

Specifically, in the flag setting process, the threshold value of V is set in advance by comparing the operation amounts of the double point operation using the lookup table and the double point operation using the non-lookup table method.

The second aspect of the present invention further provides a point doubling operation system for elliptic curve cryptography, comprising: the device comprises a parameter determining unit, a lookup table generating unit and a point doubling operation unit;

the parameter determining unit comprises a first calculating module and a dividing module;

the dividing module is used for dividing the digit N of the elliptic curve order into (N + V-1)/V units according to V bits;

the calculation module is used for calculating the occupied space of the points (x, y) on the elliptic curve according to the digit N bits of the elliptic curve order, and preferably, the occupied space of the points (x, y) on the elliptic curve is N/4 bytes; and also for calculating the number of points (x, y) on the elliptic curve; and the device is used for calculating the size of a lookup table according to the number of points (x, y) on the elliptic curve and calculating the maximum value of V according to the size of the lookup table and the size of a device memory;

the lookup table generating unit comprises a second calculating module and a constructing module;

the second calculation module is used for calculatingFor each k ∈ [1,2 ]^V-1]Sequentially calculating k x 2^iVG, wherein,g is a base point; generating a lookup table of each divided unit according to a calculation result, and storing the lookup table in the equipment memory;

calculate N% V, and calculateWherein, k ∈ [1,2 ]^N％V-1]；

The construction module is used for constructing and generating a lookup table of each divided unit according to a calculation result and storing the lookup table in the equipment memory;

the point doubling operation unit comprises a result acquisition module and a point addition module;

the result acquisition module is used for sequentially acquiring corresponding calculation results from the lookup tables of the divided units according to different values of K;

and the point addition module is used for performing point addition operation on each obtained calculation result to obtain a point multiplication result of a K-time point [ K ] G of the elliptic curve base point G.

Specifically, the calculating module calculates the number of the points (x, y) on the elliptic curve specifically as follows:

the calculation module calculates the size of the lookup table according to the number of the points (x, y) on the elliptic curve, specifically:

the calculation module calculates the maximum value of V according to the size of the lookup table and the size of the device memory, specifically: order toCalculating the maximum value of V; wherein S is a device memory and has a unit of bytes.

Specifically, if the value of N% V is 0, the dividing module divides the number N of bits of the elliptic curve order into N/V units according to V bits, and the calculating module calculates the number of points (x, y) on the elliptic curve specifically as follows:

the calculation module calculates the size of the lookup table according to the number of the points (x, y) on the elliptic curve, specifically:

the computing moduleCalculating the maximum value of V according to the size of the lookup table and the size of the equipment memory specifically comprises the following steps: order toCalculating the maximum value of V; wherein S is a device memory and has a unit of bytes.

Specifically, the multiple point operation system further comprises a marking unit, wherein the marking unit comprises a setting module and a judging module;

the setting module is used for setting the threshold value of the preset V as a mark for judging whether to use the lookup table to carry out point doubling operation;

the judging module is used for judging according to the set threshold value of the V of the point doubling operation, and if the V is not less than the preset threshold value, the point doubling operation is carried out by using a lookup table; otherwise, using a non-lookup table method to perform the multiple point operation.

Specifically, the marking unit further includes a comparison module for setting the threshold value of V in advance by comparing the operation amounts of the doubling operation using the lookup table and the doubling operation using the non-lookup table method.

The maximum value of V bit is calculated through the digit N of the elliptic curve order, the number of the calculated points (x, y) on the elliptic curve, the size parameter of the lookup table and the size of the equipment memory; then, the calculation of the lookup table of each unit is carried out through the calculated size of the lookup table, the equipment resources and the calculated size of the V bit, so that the lookup table corresponding to the equipment resources is constructed and generated, different equipment resources can be dynamically adapted, and the method has the characteristic of strong adaptability;

in the process of carrying out the point doubling operation, according to the K value, a corresponding calculation result can be quickly obtained through constructing a generated lookup table to carry out the point addition operation, so that the calculation speed of the point doubling operation is improved, and the point doubling operation can be carried out by using a lookup table method under the condition of less equipment resources without being limited by the equipment resources;

whether the multiple point operation is carried out by using the lookup table is judged by setting the multiple point operation mark, so that the flexible application of the system is ensured, and the operation speed is improved.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.