阅读说明：本技术 一种非易失性存储器及其数据处理方法 (Nonvolatile memory and data processing method thereof ) 是由 侯正义 王昭昊 王朝 王旻 赵巍胜 于 2021-09-08 设计创作，主要内容包括：本发明提供一种非易失性存储器及其数据处理方法,所述非易失性存储器包括控制器、译码器和存储器阵列,其中：控制器分别与所述译码器和所述存储器阵列相连；存储器阵列包括真随机数发生单元和物理不可克隆函数单元,真随机数发生单元用于产生随机数序列,控制器根据所述随机数序列和预设算法生成随机字符串,并将生成的随机字符串存储到物理不可克隆函数单元形成物理不可克隆函数。所述数据处理方法应用于上述非易失性存储器。本发明实施例提供的非易失性存储器及其数据处理方法,利用存储器阵列实现随机字符串的生成和存储,从而实现PUF与存储器的复用以及PUF的刷新,无需使用外部独立的TRNG,减少了硬件安全电路的体积。(The invention provides a nonvolatile memory and a data processing method thereof, wherein the nonvolatile memory comprises a controller, a decoder and a memory array, wherein: the controller is respectively connected with the decoder and the memory array; the memory array comprises a true random number generating unit and a physical unclonable function unit, wherein the true random number generating unit is used for generating a random number sequence, the controller generates a random character string according to the random number sequence and a preset algorithm, and the generated random character string is stored in the physical unclonable function unit to form a physical unclonable function. The data processing method is applied to the nonvolatile memory. According to the nonvolatile memory and the data processing method thereof provided by the embodiment of the invention, the random character string is generated and stored by using the memory array, so that the multiplexing of the PUF and the memory and the refreshing of the PUF are realized, an external independent TRNG is not required, and the volume of a hardware security circuit is reduced.)

1. A non-volatile memory comprising a controller, a decoder, and a memory array, wherein:

the controller is respectively connected with the decoder and the memory array;

the memory array comprises a true random number generation unit and a physical unclonable function unit, the true random number generation unit is used for generating a random number sequence, the controller generates a random character string according to the random number sequence and a preset algorithm, and the generated random character string is stored in the physical unclonable function unit to form a physical unclonable function.

2. The non-volatile memory of claim 1, wherein the true random number generating unit and the physical unclonable function unit are disposed on a same memory block of the memory array.

3. The non-volatile memory of claim 1, wherein the true random number generating unit and the physical unclonable function unit are disposed on different memory blocks of the memory array.

4. A data processing method using the nonvolatile memory according to any one of claims 1 to 3, comprising:

the controller reads the random number sequence from the true random number generating unit; wherein the random number sequence is pre-generated;

the controller encrypts each segment of random number in the random number sequence based on a preset algorithm to obtain a random character string corresponding to each segment of random number;

and the controller stores the random character string corresponding to each random number segment to the physical unclonable unit to form a physical unclonable function.

5. The method of claim 4, wherein the step of generating the sequence of random numbers comprises:

the controller generates a random number sequence through the true random number generating unit;

the controller stores the sequence of random numbers to the true random number generating unit.

6. The method of claim 4, further comprising:

and the controller receives a reset instruction and clears the random character string stored in the physical unclonable function unit.

7. The method of claim 6, further comprising:

the controller receives a reconfiguration instruction and reads a random number sequence from the true random number generation unit;

the controller encrypts each segment of random number in the random number sequence based on the preset algorithm to obtain a random character string corresponding to each segment of random number;

and the controller stores the random character string corresponding to each random number segment to the physical unclonable unit to form a physical unclonable function.

8. The method of any of claims 4 to 7, further comprising:

and the controller receives a refreshing instruction to refresh the random number sequence stored in the true random number generating unit, so that the refreshing of the physical unclonable function is realized.

9. A hardware cryptographic chip comprising a non-volatile memory according to any of claims 1 to 3.

10. A computer device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor comprises the hardware cryptographic chip of claim 9.

Technical Field

The invention relates to the technical field of semiconductor devices, in particular to a nonvolatile memory and a data processing method thereof.

Background

A Physical Unclonable Function (PUF) is a hardware security technique that exploits inherent device differences to produce an Unclonable unique device response to a given input.

In the prior art, a method for implementing a physical unclonable function inside a Static Random-Access Memory (SRAM for short) has been proposed, and switching between a PUF and an SRAM is implemented by modifying a conventional SRAM cell structure. And the PUF is realized by adopting the SRAM, occupies the whole SRAM storage array, and data are completely lost after the SRAM is powered off. Further, an independent True Random Number Generator (TRNG) module based on a ring oscillator is used to generate a Random Number sequence, and the Random numbers generated by the TRNG are sequentially assigned to a Resistive Random Access Memory (RRAM) array to form a PUF array, but an external independent TRNG is required to generate the Random Number sequence, which increases the chip area, and the PUF always occupies RRAM cells, thereby increasing the area overhead and power consumption of the chip.

Disclosure of Invention

In view of the problems in the prior art, embodiments of the present invention provide a nonvolatile memory and a data processing method thereof, which can at least partially solve the problems in the prior art.

In a first aspect, the present invention provides a non-volatile memory, including a controller, a decoder, and a memory array, wherein:

the controller is respectively connected with the decoder and the memory array;

the memory array comprises a true random number generation unit and a physical unclonable function unit, the true random number generation unit is used for generating a random number sequence, the controller generates a random character string according to the random number sequence and a preset algorithm, and the generated random character string is stored in the physical unclonable function unit to form a physical unclonable function.

Further, the true random number generating unit and the physical unclonable function unit are disposed on a same memory block of the memory array.

Further, the true random number generating unit and the physical unclonable function unit are disposed on different memory blocks of the memory array.

In a second aspect, the present invention provides a data processing method using the nonvolatile memory according to any of the above embodiments, including:

the controller reads the random number sequence from the true random number generating unit; wherein the random number sequence is pre-generated;

the controller encrypts each segment of random number in the random number sequence based on a preset algorithm to obtain a random character string corresponding to each segment of random number;

and the controller stores the random character string corresponding to each random number segment to the physical unclonable unit to form a physical unclonable function.

Further, the step of generating the random number sequence comprises:

the controller generates a random number sequence through the true random number generating unit;

the controller stores the sequence of random numbers to the true random number generating unit.

Further, the data processing method of the nonvolatile memory further includes:

and the controller receives a reset instruction and clears the random character string stored in the physical unclonable function unit.

Further, the data processing method of the nonvolatile memory further includes:

the controller receives a reconfiguration instruction and reads a random number sequence from the true random number generation unit;

the controller encrypts each segment of random number in the random number sequence based on the preset algorithm to obtain a random character string corresponding to each segment of random number;

and the controller stores the random character string corresponding to each random number segment to the physical unclonable unit to form a physical unclonable function.

Further, the data processing method of the nonvolatile memory further includes:

and the controller receives a refreshing instruction to refresh the random number sequence stored in the true random number generating unit, so that the refreshing of the physical unclonable function is realized.

In a third aspect, the present invention provides a hardware cryptographic chip, including the nonvolatile memory described in any of the above embodiments.

In a fourth aspect, the present invention provides a computer device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor comprises the hardware cryptographic chip of the above embodiments.

The nonvolatile memory and the data processing method thereof provided by the embodiment of the invention comprise a controller, a decoder and a memory array, wherein the controller is respectively connected with the decoder and the memory array, the memory array comprises a true random number generating unit and a physical unclonable function unit, the true random number generating unit is used for generating a random number sequence, the controller generates a random character string according to the random number sequence and a preset algorithm, the generated random character string is stored in the physical unclonable function unit to form a physical unclonable function, and the memory array is used for realizing the generation and the storage of the random character string, so that the multiplexing of the PUF and the memory and the refreshing of the PUF are realized, an external independent TRNG is not required to be used, and the volume of a hardware security circuit is reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts. In the drawings:

fig. 1 is a schematic structural diagram of a nonvolatile memory according to an embodiment of the present invention.

Fig. 2 is a flowchart illustrating a data processing method of a nonvolatile memory according to an embodiment of the present invention.

Fig. 3 is a flowchart illustrating a data processing method of a non-volatile memory according to another embodiment of the present invention.

Fig. 4 is a flowchart illustrating a data processing method of a nonvolatile memory according to another embodiment of the present invention.

FIG. 5 is a flowchart illustrating a data processing method of a nonvolatile memory according to still another embodiment of the present invention.

Fig. 6 is a schematic physical structure diagram of a computer device according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the embodiments of the present invention are further described in detail below with reference to the accompanying drawings. The exemplary embodiments and descriptions of the present invention are provided to explain the present invention, but not to limit the present invention. It should be noted that the embodiments and features of the embodiments in the present application may be arbitrarily combined with each other without conflict.

In order to facilitate understanding of the technical solutions provided in the present application, the following first describes relevant contents of the technical solutions in the present application.

Physical unclonable function: a PUF is a low-cost hardware security primitive that utilizes chip internal features to implement high-security hardware protection functions. Certain excitation is input to the PUF circuit, unique corresponding random output response can be obtained, and different excitation can obtain different output responses; in addition, due to the existence of physical deviation among chips, different PUF circuits of the same circuit structure will also obtain different output responses for the same input stimuli. The PUF may be used to generate a key or an identification ID of the chip.

Fig. 1 is a schematic structural diagram of a nonvolatile memory according to an embodiment of the present invention, and as shown in fig. 1, the nonvolatile memory according to the embodiment of the present invention includes a controller 1, a decoder 2, and a memory array 3, where:

the controller 1 is respectively connected with the decoder 2 and the memory array 3;

the memory array 3 comprises a true random number generating unit 31 and a physical unclonable function unit 32, wherein the true random number generating unit 31 is used for generating a random number sequence, the controller 1 generates a random character string according to the random number sequence and a preset algorithm, and stores the generated random character string in the physical unclonable function unit 32 to form a physical unclonable function.

Specifically, the memory array 3 may be divided into a plurality of memory blocks, one or more of which may be used as the true random number generation unit 31, and one or more of which may be used as the physical unclonable function unit 32. The true random number generation unit 31 can generate a random number sequence and store the random number sequence in the true random number generation unit 31, the controller 1 can obtain the random number sequence from the true random number generation unit 31, then generate a random character string according to the random number sequence and a preset algorithm, store the random character string in the physical unclonable function unit 32 to form a PUF, and when the PUF is required to be used for security application (key generation, chip identification, or the like), the controller 1 can obtain the random character string stored in the physical unclonable function unit 32. The controller 1 needs to access the data stored in the memory array 3 through the decoder 2. When not used for a PUF, the physical unclonable function unit 32 may store data such that the memory block in which the physical unclonable function unit 32 is located serves as a multiplexing area for the PUF and the stored data, but the random number sequence stored by the true random number generating unit 31 remains unchanged. The non-volatile Memory includes, but is not limited to, RRAM, Ferroelectric Random Access Memory (FeRAM), and Magnetic Random Access Memory (MRAM). The number of the memory blocks divided by the memory array 3 is set according to actual needs, and the embodiment of the present invention is not limited.

The nonvolatile memory provided by the embodiment of the invention comprises a controller, a decoder and a memory array, wherein the controller is respectively connected with the decoder and the memory array, the memory array comprises a true random number generating unit and a physical unclonable function unit, the true random number generating unit is used for generating a random number sequence, the controller generates a random character string according to the random number sequence and a preset algorithm, the generated random character string is stored in the physical unclonable function unit to form a physical unclonable function, and the random character string is generated and stored by using the memory array, so that the multiplexing of the PUF and the memory is realized, an external independent TRNG is not needed, and the volume of a hardware security circuit is reduced. In addition, the proportion of the occupied area of the hardware safety circuit in the chip can be reduced, and the interaction speed of the chip can be improved.

On the basis of the above embodiments, further, the true random number generating unit 31 and the physical unclonable function unit 32 are disposed on the same memory block of the memory array 3.

For example, the memory cells of a set number of rows in one memory block a in the memory array 3 may be used as the true random number generation unit 31, and the remaining memory cells in the memory block a may be used as the physical unclonable function unit 32.

On the basis of the above embodiments, further, the true random number generating unit 31 and the physical unclonable function unit 32 are disposed on different memory blocks of the memory array 3.

For example, the memory block 1 is used as the true random number generation unit 31, and the memory blocks 2 to 9 are used as the physical unclonable function unit 32 in total.

Fig. 2 is a schematic flow chart of a data processing method of a nonvolatile memory according to an embodiment of the present invention, and as shown in fig. 2, on the basis of the foregoing embodiments, further, a data processing method applied to the nonvolatile memory according to any of the foregoing embodiments according to an embodiment of the present invention includes:

s201, a controller reads a random number sequence from a true random number generating unit; wherein the random number sequence is pre-generated;

in particular, the pre-generated random number sequence is stored in a true random number generating unit from which the controller can read the random number sequence.

S202, the controller encrypts each segment of random number in the random number sequence based on a preset algorithm to obtain a random character string corresponding to each segment of random number;

specifically, the controller encrypts each segment of random number in the random number sequence according to the preset algorithm to obtain a random character string corresponding to each segment of random number. The preset algorithm is set according to actual needs, and the embodiment of the invention is not limited.

For example, the preset Algorithm employs a Secure Hash Algorithm (SHA), which is a Secure encryption Algorithm proposed by the united states security bureau and can encrypt data of any length into a code word with a length equal to 512 bits.

For example, the true random number generation unit stores a random number sequence, the random number sequence includes multiple segments of 32-bit binary numbers, and the controller encrypts each segment of 32-bit binary numbers according to the secure hash algorithm SHA-512 to obtain 512-bit code words corresponding to each segment of 32-bit binary numbers.

S203, the controller stores the random character string corresponding to each random number segment in a physical unclonable unit.

Specifically, the controller stores a random string corresponding to each random number segment in a physically unclonable unit for use in security applications (key generation, chip identification, etc.) using the PUF.

According to the data processing method of the nonvolatile memory, provided by the embodiment of the invention, the controller reads the random number sequence from the true random number generation unit, encrypts each segment of random number in the random number sequence based on a preset algorithm to obtain the random character string corresponding to each segment of random number, and stores the random character string corresponding to each segment of random number in the physical unclonable unit to form a physical unclonable function, so that an external independent TRNG is not required to be used, a PUF is realized, and the volume of a hardware security circuit is reduced. Multiplexing of the physically unclonable function unit PUF and storage is also achieved.

Fig. 3 is a schematic flow chart of a data processing method of a non-volatile memory according to another embodiment of the present invention, and as shown in fig. 3, on the basis of the foregoing embodiments, the step of generating the random number sequence further includes:

s301, the controller generates a random number sequence through the true random number generating unit;

specifically, the controller may act on the true random number generating unit through a current or a magnetic field, so that the true random number generating unit generates a random number sequence, and then obtains the random number sequence.

For example, the nonvolatile memory is an SOT-MRAM, and by using the random switching characteristic of the SOT-MTJ, the controller may apply a write current or an external magnetic field to each SOT device unit in the true random number generating unit to change the magnetization state of the free layer of the MTJ from the vertical magnetization direction to the horizontal magnetization direction, and then remove the current or the magnetic field, at this time, the magnetization direction of the free layer may be randomly switched to a certain final state, and the controller applies a read current to the true random number generating unit to read the resistance of the true random number generating unit at this time, so as to obtain the random number sequence.

S302, the controller stores the random number sequence to the true random number generating unit.

In particular, the controller may store the random number sequence to the true random number generation unit after obtaining the random number sequence.

On the basis of the foregoing embodiments, further, the data processing method of the nonvolatile memory according to the embodiment of the present invention further includes:

and the controller receives a reset instruction and clears the random character string stored in the physical unclonable function unit.

Specifically, when the physical unclonable function unit needs to be used as a normal memory, a reset instruction may be issued to the controller, and after the controller receives the reset instruction, the random character string stored in the physical unclonable function unit may be cleared, so as to improve security. It should be noted that, at this time, the random number sequence stored by the true random number generating unit remains unchanged.

Fig. 4 is a schematic flow chart of a data processing method of a nonvolatile memory according to yet another embodiment of the present invention, and as shown in fig. 4, on the basis of the foregoing embodiments, further, the data processing method of the nonvolatile memory according to the embodiment of the present invention further includes:

s401, the controller receives a reconstruction instruction and reads a random number sequence from the true random number generating unit;

specifically, after the physical unclonable function unit is used as a normal memory, if the physical unclonable function unit is used as a PUF for security application (key generation, chip identification, or the like), a reconfiguration instruction may be issued to the controller, and after the reconfiguration instruction is received by the controller, the random number sequence is read from the true random number generation unit.

S402, the controller encrypts each segment of random number in the random number sequence based on the preset algorithm to obtain a random character string corresponding to each segment of random number;

specifically, the controller encrypts each segment of random number in the random number sequence according to the preset algorithm to obtain a random character string corresponding to each segment of random number.

And S403, the controller stores the random character string corresponding to each random number segment in a physical unclonable unit to form a physical unclonable function.

Specifically, the controller stores a random string corresponding to each random number segment in a physically unclonable unit for use in security applications (key generation, chip identification, etc.) using the PUF.

On the basis of the foregoing embodiments, further, the data processing method of the nonvolatile memory according to the embodiment of the present invention further includes:

and the controller refreshes the random number sequence stored in the true random number generating unit according to the refreshing instruction, so that the refreshing of the physical unclonable function is realized.

Specifically, a refresh command may be issued to the controller, and after receiving the refresh command, the controller may refresh the random number sequence stored in the true random number generation unit, and generate a new PUF by updating the random number sequence, so as to implement the refresh of the PUF, thereby improving the security. The process of refreshing the random number sequence is similar to the process of generating the random number sequence in steps S301 and S302, and is not described herein again.

Fig. 5 is a flowchart illustrating a data processing method of a nonvolatile memory according to still another embodiment of the present invention, and as shown in fig. 5, the data processing process of the SOT-MRAM is specifically described by taking the SOT-MRAM as the nonvolatile memory as an example. It can be understood that the data processing method of the nonvolatile memory provided by the embodiment of the present invention can be applied to the nonvolatile memory capable of forming the true random number generating unit by using the memory array.

First, a random number sequence is generated. The SOT-MRAM is partitioned, and a plurality of rows of memory cells in a certain memory block are selected as true random number generating cells. And introducing SOT current to the true random number generating unit, pulling the SOT-MTJ from the perpendicular magnetization direction to the in-plane magnetization direction, and then removing the current to randomly turn to a certain final state under the interference of thermal disturbance. At this time, the resistance value corresponding to each unit in the true random number generating unit corresponds to the generated random number sequence, and the controller reads each resistance value and stores the obtained random number sequence into the true random number generating unit.

And secondly, generating a random character string. And introducing a reading current between the upper electrode and any bottom electrode of the SOT-MTJ, sequentially reading the data corresponding to the resistance value of the true random number generating unit, and acquiring a random number sequence from the true random number generating unit by the controller. The controller divides the random number sequence into N sections of random data, and encrypts each section of random data respectively based on a secure hash algorithm SHA-512 to obtain 512-bit code words corresponding to each section of random number.

And thirdly, storing the random character string. The controller stores each 512-bit code word into a PUF cell.

And fourthly, performing security verification. The controller analyzes the input excitation through the decoder, carries out addressing according to the input excitation, finds the data stored in the corresponding physical unclonable function unit, and forms a excitation-response pair (CRP) as an output response of the input excitation, wherein the CRP can be used for PUF security authentication. The input stimulus may be a string of characters, which is set according to actual needs, and the embodiment of the present invention is not limited.

And step five, switching to a memory. When the SOT-MRAM needs to be used as a memory, a reset instruction is issued to the controller, and the PUF unit can be reset by the controller after the controller receives the reset instruction and is used for storing data. At the moment, the true random number generating unit keeps the current state unchanged, namely the stored random number sequence is unchanged; when the SOT-MRAM is required to be used as the PUF, the second step and the third step are repeated, so that each 512-bit code word is stored in the PUF unit.

And sixthly, refreshing the PUF unit. Because the area and the data space occupied by the true random number generating unit and the PUF unit are fixed, the number of users capable of registering and authenticating is limited, when the PUF needs to be refreshed by the user or the current PUF is no longer safe, a refreshing instruction can be sent to the controller to refresh the random number sequence stored in the true random number generating unit, a new random number sequence is generated, and a new PUF is formed through the second step and the third step. The refreshing of the random number sequence stored in the PUF unit can improve the safety and the practicability.

It can be understood that, when the memory block in which the PUF cell is located is used as a memory, the true random number generation unit keeps the current random data sequence unchanged, and the remaining cells in the memory block are initialized to store data, so that data can be read and written like a normal memory. When the PUF unit needs to be used as the PUF, the controller reads out the random number sequence stored by the true random number generation unit, encrypts the random number sequence through a secure hash algorithm, and stores the obtained random character string in the PUF unit. Therefore, the PUF unit is used as the multiplexing of the PUF and the memory.

It should be noted that there is no precedence relationship between the switching of the fifth step to the memory and the refreshing of the PUF cell in the sixth step.

The nonvolatile memory and the data processing method thereof provided by the embodiment of the invention have the following beneficial effects:

(1) the PUF is realized in the nonvolatile memory, so that a single PUF module is prevented from being combined into the memory, and the area occupation ratio of a hardware security circuit in a chip is reduced.

(2) The nonvolatile memory is partitioned and only part of the memory blocks are used as PUF and TRNG, so that the memory function is reserved while the hardware security function is realized.

(3) The TRNG is realized by using a unit in the nonvolatile memory, so that a separate external TRNG is avoided, and the occupied area of the device is reduced.

(4) And the assignment from TRNG to the PUF is realized by using a preset algorithm, and the multiplexing of a memory and a PUF unit is realized.

(5) And a new random number is generated by using TRNG, so that refreshing of the PUF is realized, and the safety is improved.

An embodiment of the present invention provides a hardware encryption chip, including the nonvolatile memory described in any of the above embodiments.

An embodiment of the present invention provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, where the processor includes the hardware encryption chip described in the foregoing embodiment.

The computer device may be, for example, a personal computer, a laptop computer, a cellular telephone, a camera phone, a smartphone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or a combination of any of these devices.

Referring now to FIG. 6, shown is a schematic diagram of a computer device 600 suitable for use in implementing embodiments of the present application.

As shown in fig. 6, the computer apparatus 600 includes a Central Processing Unit (CPU)601 which can perform various appropriate works and processes according to a program stored in a Read Only Memory (ROM)602 or a program loaded from a storage section 608 into a Random Access Memory (RAM) 603. In the RAM603, various programs and data necessary for the operation of the system 600 are also stored. The CPU601, ROM602, and RAM603 are connected to each other via a bus 604. An input/output (I/O) interface 605 is also connected to bus 604.

The following components are connected to the I/O interface 605: an input portion 606 including a keyboard, a mouse, and the like; an output section 607 including a Cathode Ray Tube (CRT), a liquid crystal feedback (LCD), and the like, and a speaker and the like; a storage section 608 including a hard disk and the like; and a communication section 609 including a network interface card such as a LAN card, a modem, or the like. The communication section 609 performs communication processing via a network such as the internet. The driver 610 is also connected to the I/O interface 605 as needed. A removable medium 611 such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, or the like is mounted on the drive 610 as necessary, so that a computer program read out therefrom is mounted as necessary on the storage section 608.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The application may be described in the general context of computer-executable instructions, such as program modules, being executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. The application may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote computer storage media including memory storage devices.

The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the system embodiment, since it is substantially similar to the method embodiment, the description is simple, and for the relevant points, reference may be made to the partial description of the method embodiment.

The above description is only an example of the present application and is not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.