KR20220064653A - Cloud-based IoT device control method and system - Google Patents

Abstract

Disclosed is a cloud-based IoT device control method in which a cloud service for controlling a plurality of IoT devices is provided through a plurality of physical servers, wherein each of the physical servers includes a processor and a memory. The cloud-based IoT device control method of the present invention comprises the steps of: receiving, by a processor, profile information from a plurality of IoT devices; generating, by the processor, a plurality of virtual devices corresponding to each of the IoT devices using the received profile information; connecting, by the processor, a plurality of clients and the virtual devices in accordance with setting signals of the clients; applying, by the processor, different security levels to each of the virtual devices in accordance with the importance of the virtual devices; and encrypting, by the processor, each of the virtual devices by generating different encryption keys in accordance with the applied security levels. Therefore, a cloud-based IoT device can be safely controlled.

Description

Cloud-based IoT device control method and system {Cloud-based IoT device control method and system}

The present invention relates to a cloud-based IoT device control method and system, and more particularly, to a cloud-based IoT device control method and system excellent in security.

An Internet of Things (IoT) device refers to a physical device to which a sensor, software, and network technology are grafted. IoT devices are used in various industries, such as homes, transportation, medical care, or factories. In the home, IoT devices such as IP cameras, light bulbs, air conditioners, or vacuum cleaners may be utilized. In transportation, IoT devices such as smart traffic controllers, smart parking, or vehicle-to-vehicle communication systems may be utilized.

In general, a function of an IoT device (eg, movement of an IP camera in the case of an IP camera) may be operated through software stored in an internal memory. In order to add new functions to the IoT device or to link with other IoT devices, it is necessary to update the software stored in the internal memory of the IoT device. In particular, software updates are sometimes required due to security flaws in existing software. However, there is a possibility that an error may occur due to reasons such as power supply interruption during software update of the IoT device.

In order to solve the above problems, it is possible to control the IoT device based on the cloud. However, when controlling IoT devices based on the cloud, security issues arise. In particular, when an external intruder illegally accesses the cloud and controls the IoT device in national infrastructure such as transportation or power plants that require security, the illegal control of the IoT device may lead to a serious accident. Therefore, when the IoT device is controlled based on the cloud, a method for safely controlling the IoT device is required.

Korean Registration Publication No. 10-2015-0123374 (2015.11.04.)

A technical problem to be achieved by the present invention is to provide a method and system for controlling a cloud-based IoT device excellent in security.

A cloud service for controlling a plurality of IoT devices according to an embodiment of the present invention is provided through a plurality of physical servers, and each of the plurality of physical servers includes a processor and a memory. The cloud-based IoT device control method includes the processor receiving respective profile information from each of a plurality of IoT devices, the processor generating a plurality of virtual devices corresponding to each of the plurality of IoT devices by using the received respective profile information; the processor connecting the plurality of clients and the plurality of virtual devices to each other according to setting signals of the plurality of clients; applying a different security level, and the processor encrypts each of the plurality of virtual devices by generating different encryption keys according to the applied security level.

As the number of the applied security level is smaller, the security of the plurality of virtual devices is further strengthened, and different encryption keys of the plurality of virtual devices are sequentially generated starting from the number of the applied security level is small.

When the security level applied to any one of the plurality of virtual devices is level 1, the processor determines the highest secret key shared only by clients that can access the level 1 virtual device with respect to the virtual device to which the level 1 is applied. A first-class encryption key is generated using the hash function result value and the hash function result value of the ID of the virtual device to which the first-class is applied, and when the security level applied to the other one of the plurality of virtual devices is n-class, The processor determines the hash function result value of the encryption key of the (n-1) grade for the virtual device to which the n grade (n is a natural number greater than or equal to 2) is applied, and the hash function result value of the ID of the virtual device to which the n grade is applied. to generate an n-grade encryption key.

The processor grants different access rights to a plurality of clients, and all the authorized clients receive the first-class encryption key generated by the processor.

A cloud-based IoT device control system according to an embodiment of the present invention includes a processor that executes instructions, and a memory that stores the instructions. The commands receive respective profile information from each of the plurality of IoT devices, and generate a plurality of virtual devices corresponding to each of the plurality of IoT devices by using the received respective profile information, and Connecting the plurality of clients and the plurality of virtual devices to each other according to setting signals, applying different security levels to each of the plurality of virtual devices according to the importance of the plurality of virtual devices, and applying the applied security It is implemented to encrypt each of the plurality of virtual devices by generating different encryption keys according to the grade. The processor and the memory are implemented in a physical server, and a cloud service is provided through the physical server.

A cloud-based IoT device control method and system according to an embodiment of the present invention By applying different security levels according to the importance of virtual devices, it is possible to safely control cloud-based IoT devices.

In order to more fully understand the drawings recited in the Detailed Description, a detailed description of each drawing is provided.
1 is a block diagram of a cloud-based IoT device control system according to an embodiment of the present invention.
2 and 3 are flowcharts illustrating a cloud-based IoT device control method according to an embodiment of the present invention.
4 is a block diagram illustrating an operation of a client capable of accessing a virtual device according to an embodiment of the present invention.
5 is a block diagram illustrating an operation of creating a virtual device and setting a security level according to an embodiment of the present invention.

Specific structural or functional descriptions of the embodiments according to the concept of the present invention disclosed in this specification are only exemplified for the purpose of explaining the embodiments according to the concept of the present invention, and the embodiments according to the concept of the present invention are It may be implemented in various forms and is not limited to the embodiments described herein.

Since the embodiments according to the concept of the present invention may have various changes and may have various forms, the embodiments will be illustrated in the drawings and described in detail herein. However, this is not intended to limit the embodiments according to the concept of the present invention to specific disclosed forms, and includes all modifications, equivalents, or substitutes included in the spirit and scope of the present invention.

Terms such as first or second may be used to describe various elements, but the elements should not be limited by the terms.

The terms used herein are used only to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present specification, terms such as "comprise" or "have" are intended to designate that the described feature, number, step, operation, component, part, or a combination thereof exists, but one or more other features or numbers , it is to be understood that it does not preclude the possibility of the existence or addition of steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present specification. does not

Hereinafter, the present invention will be described in detail by describing preferred embodiments of the present invention with reference to the accompanying drawings.

1 is a block diagram of a cloud-based IoT device control system according to an embodiment of the present invention.

Referring to FIG. 1 , the cloud-based IoT device control system 100 refers to a system for controlling a plurality of IoT devices 10-1 to 10-K; K is a natural number through the cloud service 30 . The cloud-based IoT device control system 100 may be used in a home for building a smart home, a factory for building a smart factory, a hospital, a national infrastructure traffic control system, or a nuclear power plant. can Controlling the IoT devices 10-1 to 10-K means driving the IoT devices 10-1 to 10-K, interworking with other IoT devices, or the IoT devices 10-1 to 10-K ) means an operation such as an update of a new function. Security is important for controlling the IoT devices 10-1 to 10-K. It is assumed that the cloud-based IoT device control system 100 is utilized at home. If a person without authority controls a plurality of IoT devices through the cloud service 30 , the person without authority may illegally leak data including personal information to the outside. This can lead to privacy issues. Also, it is assumed that the cloud-based IoT device control system 100 is utilized in a factory, a hospital, or a nuclear power plant. If a person without authority controls a plurality of IoT devices through the cloud service 30, the person without authority stops or controls the operation of some IoT devices of a factory, hospital, or nuclear power plant to operate incorrectly Doing so can cause a factory, hospital, or nuclear power plant to malfunction. Accordingly, the present invention discloses a security technology capable of safely controlling the IoT devices 10-1 to 10-K.

The cloud-based IoT device control system 100 provides a plurality of IoT devices 10-1 to 10-K, a plurality of clients 20-1 to 20-N; N is a natural number), and a cloud service 30 . include A plurality of IoT devices (10-1 to 10-K; K is a natural number), a plurality of clients (20-1 to 20-N), and the cloud service 30 may transmit and receive data through the network 101 . can

The plurality of IoT devices 10 - 1 to 10 -K refer to devices whose operation can be controlled through the cloud service 30 or whose new function can be updated. When the cloud-based IoT device control system 100 is used at home, each of the plurality of IoT devices 10-1 to 10-K may be an LED light bulb, a vacuum cleaner, a refrigerator, an air conditioner, or a smart speaker. In the home, each member can control the operation by directly manipulating an IoT device (10-1, 10-2, ..., or 10-K), such as an LED light bulb, vacuum cleaner, air conditioner, or smart speaker, but the client (20 -1, 20-2, ..., or 20-N) may access the cloud service 30 to control the IoT device 10-1, 10-2, ..., or 10-K . For example, each member may directly press a switch implemented in the house to turn on the LED bulb, but may use the client 20-1 to turn on the LED bulb. In addition, according to an embodiment, when the cloud-based IoT device control system 100 is used in a hospital, each of the plurality of IoT devices 10-1 to 10-K may be a medical device, an LED light bulb, or an air conditioner. there is.

Each of the plurality of clients 20-1 to 20-N refers to an electronic device capable of accessing the cloud service 30 through the network 101, such as a smart phone, a tablet PC, a notebook computer, or a PC. A user is an administrator for controlling the IoT device (10-1, 10-2, ..., or 10-K) and uses the client (20-1, 20-2, ..., or 20-N) to control the IoT device (10-1, 10-2, ..., or 10-K).

The cloud service 30 controls the IoT device 10-1, 10-2, ..., or 10-K by the user of the client 20-1, 20-2, ..., or 20-N provide services for The cloud service 30 is a virtual server and may be referred to as a cloud server, cloud computing, or a cloud-based service. The cloud service 30 is provided through a plurality of physical servers 40 , 50 , and 60 . The plurality of physical servers 40 , 50 , and 60 may be divided into a plurality of groups. In FIG. 1 , the plurality of physical servers 40 , 50 , and 60 are illustrated as being divided into three groups, but the present invention is not limited thereto. Each of the first plurality of physical servers 40 , the second plurality of physical servers 50 , and the third plurality of physical servers 60 is implemented as a plurality of physical servers. The first plurality of physical servers 40 , the second plurality of physical servers 50 , and the third plurality of physical servers 60 may be managed by different entities. For example, the company that manages the first plurality of physical servers 40, the company that manages the second plurality of physical servers 50, and the company that manages the third plurality of physical servers 60 are different from each other. could be a company. The company that manages the plurality of second physical servers 50 may be a company that has been entrusted with the company that manages the plurality of first physical servers 40 . In addition, the company that manages the third plurality of physical servers 60 receives re-entrustment from the company that manages the second plurality of physical servers 50 , or manages the first plurality of physical servers 40 . It may be a company that has been entrusted with the company. Each of the first plurality of physical servers 40 includes a processor and a memory. In FIG. 1 , a processor 41 and a memory 43 of any one of the first plurality of physical servers 40 are typically shown. Each of the second plurality of physical servers 50 includes a processor and a memory. In FIG. 1 , a processor 51 and a memory 53 of any one of the plurality of second physical servers 50 are typically shown. Each of the third plurality of physical servers 60 includes a processor and a memory. In FIG. 1 , a processor 61 and a memory 63 of any one of the plurality of third physical servers 60 are typically shown. The processor 41, 51, or 61 executes instructions for controlling the cloud-based IoT device 10-1, 10-2, ..., or 10-K. A memory 43, 53, or 63 stores the instructions. However, the cloud service 30 does not require the users of the plurality of clients 20 - 1 to 20 -N to know the specific locations and configurations of the physical servers 40 , 50 , and 60 .

2 and 3 are flowcharts illustrating a cloud-based IoT device control method according to an embodiment of the present invention.

1 and 2 , each of the plurality of IoT devices 10-1 to 10-K transmits respective profile information to the cloud service 30 through the network 101 (S10). ). The profile information includes type information, location information, ID, or operation information of the IoT device 10-1, 10-2, ..., or 10-K. For example, assuming that the IoT device 10-1, 10-2, ..., or 10-K is an IP camera, the profile information is a camera as type information, a room as location information, and a camera as motion information. It may include movement, movement down, movement to the left, movement to the right.

The cloud service 30 receives the respective profile information from each of the plurality of IoT devices 10-1 to 10-K through the network 101 (S20). Since the cloud service 30 is provided through a plurality of physical servers 40 , 50 , and 60 , the operations of the cloud service 30 may be understood as operations of the physical servers 40 , 50 , and 60 . there is. Since each of the physical servers 40 , 50 , and 60 includes a processor 41 , 51 , or 61 and a memory 43 , 53 , or 63 , the operations of the cloud service 30 are performed on the physical servers 40 , 50 , and 60 ) may also be understood as operations of the respective processors 41 , 51 , or 61 . Hereinafter, the operations of the cloud service 30 are the operations of the physical servers 40 , 50 , and 60 , or the operations of the processors 41 , 51 , and 61 of the physical servers 40 , 50 , and 60 . can be understood as Conversely, the operations of the physical servers 40 , 50 , and 60 , or the operations of the processors 41 , 51 , and 61 of the physical servers 40 , 50 , and 60 , are the operations of the cloud service 30 . can be understood as their actions. That is, the processor (eg, 41 ) of any one of the physical servers 40 , 50 , and 60 is each from each of the plurality of IoT devices 10-1, 10-2, ..., and 10-K. Receive profile information of

The processor 41 uses each of the received profile information to generate a plurality of virtual devices 11- corresponding to each of the plurality of IoT devices 10-1, 10-2, ..., and 10-K. 1 to 11-M; M is a natural number) is generated (S30). The plurality of virtual devices 11-1 to 11-M are implemented as software in the cloud service 30 . For example, the virtual device 11-1 corresponding to the first IoT device 10-1 implemented in hardware is implemented as software in the cloud service 30 . For example, when the first IoT device 10-1 is a fan and the second IoT device 10-2 is a thermometer, a first virtual device ( 11-1) and a second virtual device 11-2 corresponding to the second IoT device 10-2 are created. That is, by accessing and controlling the virtual device 11-1, physical control of the virtual device 11-1 and the corresponding IoT device 10-1 is possible. For example, by accessing the virtual device 11-1 and adjusting the speed of the fan, it is possible to control the speed of the fan, which is substantially the physical IoT device 10-1.

Also, according to an embodiment, several virtual devices (eg, 11-1 and 11-2) may be combined to create a new virtual device (eg, 11-3). One new virtual device 11-3 does not correspond to the IoT device 10-1, 10-2, ..., or 10-K implemented in hardware. For example, the first virtual device 11-1, which is a virtual fan, and the second virtual device 11-2, which is a virtual thermometer, combine to create a third virtual device 11-3, which is a virtual smart fan. There may be no IoT devices 10-1, 10-2, ..., 10-K corresponding to the third virtual device 11-3, which is the virtual smart fan.

Profile information (eg, type information, location information, ID, or ID information of an IoT device) of the plurality of virtual devices 11-1 to 11-M displayed on each of the plurality of clients 20-1 to 20-N Setting signals are generated by selecting or inputting . The plurality of clients 20-1 to 20-N transmits the generated setting signals to the processor 41 (S40). The processor 41 receives the generated setting signals from the plurality of clients 20-1 to 20-N (S50). The processor 41 includes the plurality of clients 20-1 to 20-N and the plurality of virtual devices 11-1 to 11- according to the setting signals of the plurality of clients 20-1 to 20-N. M) are connected to each other (S60). The setting signals are the plurality of clients 20-1 to 20-N, respectively, by users of each of the plurality of clients 20-1 to 20-N and the plurality of virtual devices 11-1 to 11- Profile information (eg, type information, location information, or ID information of the IoT device) is selected or entered. The setting signals are generated according to the selection or input, and the setting signals are transmitted from the clients 20 - 1 to 20 -N to the cloud service 30 . The cloud service 30 selects each virtual device corresponding to the received setting signals from among the plurality of virtual devices 11-1 to 11-M, and communicates with the plurality of clients 20-1 to 20-N. A plurality of virtual devices 11-1 to 11-M are connected to each other. For example, the user of the first client 20-1 connects the first client 20-1 with the first virtual device 11-1 corresponding to the first IoT device 10-1. In step 20-1, profile information (eg, type information of an LED bulb and an LED bulb ID) of the first virtual device 11-1 may be selected. A setting signal is generated according to the user's selection of the first client 20 - 1 , and the generated setting signal is transmitted to the cloud service 30 . The processor 41 selects a corresponding virtual device (eg, 11-1) from among the virtual devices 11-1 to 11-M according to the received setting signal, and connects the first client 20-1 with the first client 20-1. One virtual device 11 - 1 can be connected to each other. That is, the first client 20 - 1 is in a ready state to control the first virtual device 11 - 1 .

The processor 41 applies different security levels to each of the plurality of virtual devices 11-1 to 11-M according to the importance of the plurality of virtual devices 11-1 to 11-M (S70) .

The importance is determined according to risk and sensitivity. The risk refers to a degree of physical, physical, or property damage due to a malfunction of the virtual device 11-1, 11-2, ..., or 11-M. For example, when the virtual device 11-1 is a thermometer, the thermometer itself is safe because it cannot physically or physically harm a person. That is, when the virtual device 11 - 1 is a thermometer, the degree of risk is low. On the other hand, when the virtual device 11 - 2 is a heater, there is a risk of causing a fire when overheating for a long time and physically or physically harming people. That is, when the virtual device 11 - 2 is a heater, the risk is high. The risk has a range between 1 and 100. The processor 41 sets the risk level for the plurality of virtual devices 11-1 to 11-M according to whether a motor, a heating component, or a hazardous substance is included. The sensitivity refers to a degree of exposure of an individual's privacy due to a malfunction of the virtual device 11-1, 11-2, ..., or 11-M. For example, when the virtual device 11-3 is an IP camera, there is a possibility that the user's privacy is exposed. The sensitivity ranges from 1 to 100. The processor 41 sets sensitivities for the plurality of virtual devices 11-1 to 11-M according to whether a camera module, a microphone, or a fingerprint sensor is included. The higher the number of the risk and the sensitivity, the higher the security level. That is, the higher the number of the risk and the sensitivity, the higher the security level is required.

According to an embodiment, the importance may be determined in consideration of a user setting. In this case, the user setting means setting directly by the user. The user is a person who uses an IoT device (10-1, 10-2, ..., or 10-K), or a client (20-1, 20-2, ..., or 20-N) means a person who The user setting has a range between 0 and 100. The higher the number, the higher the security level of the IoT device (10-1, 10-2, ..., or 10-K). When the user setting is 100, the user can use the IoT device 10-1, 10-2, ..., or 10 through the virtual device 11-1, 11-2, ..., or 11-M. -K) cannot be controlled, and it may be set to have to control the IoT device 10-1, 10-2, ..., or 10-K by directly pressing a physical button, or the like. The security level of the plurality of virtual devices 11-1 to 11-M is determined according to Equation 1 below.

[Equation 1]

where w(d) is the security level of the virtual device 11-1, 11-2, ..., or 11-M, s is the risk, p is the sensitivity, u is the user setting, The g(s, p) denotes a rating calculation function according to risk and sensitivity.

When the score of the average of risk and sensitivity is equal to or greater than the score of the user setting, the security level of the virtual device 11-1, 11-2, ..., or 11-M is determined according to the rating calculation function. Conversely, when the score of the average of risk and sensitivity is smaller than the score of the user setting, the security level of the virtual device 11-1, 11-2, ..., or 11-M is determined according to the user setting.

The rating calculation function is shown in Table 1 below.

ranking Risk(s) Condition Sensitivity (p) One s>80 OR p>80 2 s>60 OR p>60 3 s>40 OR p>40 4 s>20 OR p>20 5 s>0 AND p>0 6 s=0 AND p=0

For example, when the score of the risk s of the virtual device 11-1 is 65 and the score of the sensitivity p is 20, the security level of the virtual device 11-1 may be determined as Level 2.

The security level according to the user setting is shown in Table 2 below.

ranking User Settings (u) One u>80 2 u>60 3 u>40 4 u>20 5 u>0 6 u=0

For example, when the score of the user setting n of the virtual device 11 - 2 is 50 points, the security level of the virtual device 11 - 2 may be determined to be 3 levels.

As the number of the security level is smaller, the security level of the plurality of virtual devices 11-1 to 11-M is higher. Level 1 is a virtual device (11-1, 11-2, ..., or 11-M) that exposes sensitive personal information or poses a physical risk, environmental destruction, human damage, large-scale catastrophe, or This means that there is a possibility of social chaos. Level 2 means that the control of the virtual device 11-1, 11-2, ..., or 11-M is impossible, and there is a possibility of a fatal defect. A grade of 3 means significant damage to the virtual device (11-1, 11-2, ..., or 11-M), and the normal operation is difficult and there is a possibility of unpredictable behavior. A grade of 4 means that there is some failure in the virtual device 11-1, 11-2, ..., or 11-M, and a failure in which a user can recognize a malfunction occurs. Grade 5 is a case in which a minor malfunction occurs in the virtual device (11-1, 11-2, ..., or 11-M), but an operation suitable for the purpose is possible, and a minor malfunction occurs at a level that is difficult for the user to recognize. it means. A grade of 6 means that the virtual device 11-1, 11-2, ..., or 11-M is not affected at all. According to an embodiment, the importance may be implemented in various ways.

1 to 3 , the processor 41 encrypts each of the plurality of virtual devices 11-1 to 11-M by generating different encryption keys according to the applied security level (S80).

4 is a block diagram illustrating an operation of a client capable of accessing a virtual device according to an embodiment of the present invention.

1 to 4 , when the security level applied to any one (eg, 11-1 or 11-2) of the plurality of virtual devices 11-1 to 11-M is level 1, the processor ( 41) generates a first-class encryption key using Equation 2 below for the IoT virtual device 11-1 or 11-2 to which the first-class is applied.

[Equation 2]

는 XOR 연산을 나타낸다. The K _G ¹ is an encryption key of level 1 when the security level is level 1, the HMAC( ) is an HMAC function, the H( ) is a hash function, and the DUID is the IoT device (10-1, 10- 2, ..., or 10-K), the K _T is the highest secret key, the

represents an XOR operation.

The hash function result value of the highest secret key (K _T ) shared only by clients (eg, 20-1 to 20-3) that can access the first-class virtual device (eg, 11-1 or 11-2) And, a first-class encryption key (K _G ¹ ) is generated using the hash function result value of the IDs of the virtual devices to which the first-class is applied (eg, 11-1 and 11-2).

When the ID of the first IoT device (eg, 10-1) is "DEV_12345", the DUID is "DEV_12345". The processor 41 calculates a result value of the hash function H( ) for the DUID "DEV_12345". The processor 41 calculates a result value of the hash function H( ) for "secret", which is the highest secret key (K _T ). The processor 41 is the result of the hash function (H( )) for the DUID "DEV_12345" and the hash function (H( )) for "secret", which is the highest secret key (K _T ). XOR operation is performed on The processor 41 generates an encryption key (K _G ¹ ) when the security level is 1 by applying the HMAC function (HMAC( )) to the XOR operation result value and the highest secret key (K _T ).

The DUID (Device Unique Identifier) is a unique ID having the attribute of a GUID (Global Unique Identifier) of the IoT device 10-1, 10-2, ..., or 10-K. The DUIDs must not be duplicated. One DUID can be mapped with one IoT (10-1, 10-2, ..., or 10-K) or virtual device (11-1, 11-2, ..., or 11-M). should be able The DUID is publicly available information.

The _KT is the highest secret key, and clients (eg, 20-1, 20-2, and 20-3) are granted access to virtual devices (eg, 11-1 and 11-2) having a security level of 1 ) is a key shared only with each other. That is, only clients (eg, 20-1, 20-2, and 20-3) to which the highest level of security (eg, grade 1) is granted accesses the highest secret key (K _T ) in the cloud service 30 . can do. That is, only clients (eg, 20-1, 20-2, and 20-3) that can access the first-class virtual device (eg, 11-1, or 11-2) are the highest secret key in the cloud service 30 . (K _T ) can be accessed. Unlike DUID, which is publicly available information, the top secret key (K _T ) must maintain confidentiality. The processor 41 grants different access rights to the plurality of clients 20-1 to 20-N. For example, the processor 41 grants first-class access rights to the first to third clients 20-1 to 20-3, and the first-grade access rights to the fourth to seventh clients 20-4 to 20-7. A lower level of 2 access authority is granted, and the 8th to 11th clients (20-8 to 20-11) can be given an access authority of a third level lower than the access authority of the second level.

Granting access rights to the first-level virtual devices (eg, 11-1 and 11-2) means that the first to third clients 20-1 to 20-3 are virtual devices with a first-level security level (eg, virtual devices). , 11-1 and 11-2) means that access and control are possible. In this case, the first to third clients 20-1 to 20-3 granted access to the first-level virtual devices (eg, 11-1 and 11-2) are virtual devices with a first-level security level. (eg, 11-1 and 11-2) as well as virtual devices (eg, 11-3 to 11-M) whose security level is lower than 1 (eg, grades 2 to 6) and control is possible.

The 4th to 7th clients 20-4 to 20-7, to which the 2nd level is assigned, include virtual devices (eg, 11-3 to 11-5) having a security level of 2 and a level lower than the 2nd level ( For example, it is possible to access and control virtual devices (eg, 11-6 to 11-M) of grades 3 to 6). However, it is impossible to access and control virtual devices (eg, 11-1 and 11-2) having a security level of 1 .

That is, clients (eg, 20-4 to 20-7) to which access of a specific grade (eg, grade 2) is granted are clients to which access rights of a lower grade than the specific grade (eg, grade 2) are granted. (eg, 20-8 to 20-12) It is possible to access and control virtual devices (eg, 11-6 to 11-15) that can be accessed and controlled. However, clients (eg, 20-4 to 20-7) granted access of a specific grade (eg, grade 2) have access of a higher grade (eg, grade 1) than the specific grade (eg, grade 2). It is impossible to access and control a virtual device (eg, 11-1 or 11-2) to which authorized clients (eg, 20-1 to 20-3) can access and control.

When the security level applied to any one (eg, 11-3) of the plurality of virtual devices 11-1 to 11-M is level n (n is a natural number greater than or equal to 2), the processor 41 determines that the level n is An n-grade encryption key is generated using Equation 3 below for the applied virtual device (eg, 11-3).

[Equation 3]

는 XOR 연산을 나타낸다. 상기 공유 비밀키는 모든 클라이언트들(20-1~20-N)끼리 공유하는 키이다. 즉, 모든 클라이언트들(20-1~20-N)은 클라우드 서비스(30)에서 공유 비밀키(K_P)에 접근할 수 있다.The K _G ⁿ is the n-grade encryption key when the security level is n, the HMAC( ) is the HMAC function, the H( ) is the hash function, and the DUID is the IoT device (10-1, 10- 2, ..., or 10-K), the K _G ^(n-1) is the (n-1) grade encryption key, the K _P is the shared secret key, the

represents an XOR operation. The shared secret key is a key shared by all clients 20-1 to 20-N. That is, all clients 20-1 to 20-N may access the shared secret key K _P in the cloud service 30 .

When the security level applied to any one (eg, 11-3) of the plurality of virtual devices 11-1 to 11-M is level n, the processor 41 determines that the level of n (n is a natural number greater than or equal to 2) is For the applied virtual device (eg, 11-3), the hash function result value of the encryption key (K _G ^(n-1) ) of the (n-1) grade and the virtual device to which the n grade is applied (eg, 11- An n-grade encryption key (K _G ⁿ ) is generated using the hash function result of the ID of 3 to 11-M).

A client (eg, 20-1, 20-2, or 20-3) granted access to virtual devices (eg, 11-1 and 11-2) having a security level of 1 causes the processor 41 to 1 It may request the processor 41 to generate encryption keys for all grades as well as the grade encryption key. For example, a client (eg, 20-1, 20-2, or 20-3) granted access to virtual devices (eg, 11-1 and 11-2) having a security level of 1 is transmitted to the processor 41 . It requests the processor 41 to generate a first-class encryption key. After the first-grade encryption key is generated according to the request of the client (eg, 20-1, 20-2, or 20-3), the second-grade encryption key (K _G ² ) may be requested from the processor 41 to be generated. . The processor 41 is a hash function (H) for the result value of the hash function (H( )) of the ID (eg, DEV_12346) of the IoT device (eg, 10-2), and the first-class encryption key (K _G ¹ ) XOR operation is performed on the result of ( )). The processor 41 may generate an encryption key (K _G ² ) when the security level is 2 by applying the HMAC function (HMAC( )) to the XOR operation result value and the shared secret key (K _G ). In addition, a client (eg, 20-1, 20-2, or 20-3) granted access to virtual devices (eg, 11-1 and 11-2) having a security level of 1 is transmitted to the processor 41 . It requests the processor 41 to generate a third-grade encryption key (K _G ³ ). After the second-grade encryption key is generated according to the request of the client (eg, 20-1, 20-2, or 20-3), the third-grade encryption key (K _G ³ ) may be requested from the processor 41 to be generated. . The processor 41 is a hash function (H) for the result value of the hash function (H( )) of the ID (eg, DEV_12347) of the IoT device (eg, 10-3), and the second-grade encryption key (K _G ² ) XOR operation is performed on the result of ( )). The processor 41 may generate an encryption key (K _G ³ ) when the security level is 3 by applying the HMAC function (HMAC( )) to the XOR operation result value and the shared secret key (K _G ). That is, the client (eg, 20-1, 20-2, or 20-3) to which the highest level of access is granted has the advantage that it is possible without additional information to generate an encryption key of a low security level (eg, grades 2 to 6). there is.

The different encryption keys of the plurality of virtual devices (11-1 to 11-M) are sequentially generated from the small number of the applied security level. That is, the different encryption keys of the plurality of virtual devices (11-1 to 11-M) are sequentially generated from the order of security level high. For example, after a level 1 encryption key of the virtual device 11-1 having a security level of 1 is generated, a level 2 encryption key of the virtual device 11-2 having a security level of level 2 is generated. After the level 2 encryption key of the virtual device 11-2 having the security level of 2 is generated, the level 3 encryption key of the virtual device 11-3 having the security level of level 3 is generated.

On the other hand, a client (eg, 20-4 to 20-7) granted access to a virtual device (eg, 11-3 to 11-7) whose security level is lower than level 1 (eg, level 2) is a processor Although 41 may request the processor 41 to generate a cryptographic key of a grade equal to or lower than its grade (eg, grade 2), its grade (eg, grade 2) , level 2) cannot be requested from the processor 41 to generate an encryption key of a higher level (eg, level 1).

The processor 41 transmits the generated encryption key to the client 20-1, 20-2, ... or 20-N (S90). For example, when the first-level encryption key of the virtual device 11-1 having the first security level is generated, the processor 41 is the client 20-1 to accessing the first-level virtual device 11-1 20-3) transmits the first-class encryption key. The client 20-1, 20-2, ... or 20-N receives the generated encryption key from the processor 41 (S100). All authorized clients (eg, 20-1, 20-2, or 20-3) receive the first-class encryption key generated by the processor 41 .

The client (20-1, 20-2, ..., or 20-N) connects to the virtual device (11-1, 11-2, ..., or 11-M) matching the class according to the received encryption key. Approach (S110). The processor 41 receives the encryption key from the client 20-1, 20-2, ..., or 20-N, and the virtual device 11-1, 11-2, ..., or 11 corresponding to the class. -M) to allow access. For example, the processor 41 receives the first-class encryption key from the client 20-1, 20-2, or 20-3, and accesses the virtual device (eg, 11-1, or 11-2) corresponding to the first-class encryption key. to allow The client 20-1, 20-2, or 20-3 accesses the virtual device (eg, 11-1 or 11-2) and an IoT device corresponding to the virtual device 11-1 or 11-2 (10-1, or 10-2) can be controlled. That is, the client 20-1, 20-2, or 20-3 accesses the virtual device (eg, 11-1 or 11-2) to drive the IoT device 10-1 or 10-2, It is possible to perform an operation such as interworking with other IoT devices or updating a new function of the IoT device 10 - 1 or 10 - 2 .

5 is a block diagram illustrating an operation of creating a virtual device and setting a security level according to an embodiment of the present invention.

Referring to FIG. 1 , the cloud service 30 is provided through a plurality of physical servers 40 , 50 , and 60 . The plurality of physical servers 40 , 50 , and 60 may be divided into a plurality of groups. In FIG. 1 , the plurality of physical servers 40 , 50 , and 60 are illustrated as being divided into three groups, but the present invention is not limited thereto. Each of the first plurality of physical servers 40 , the second plurality of physical servers 50 , and the third plurality of physical servers 60 is implemented as a plurality of physical servers. The first plurality of physical servers 40 , the second plurality of physical servers 50 , and the third plurality of physical servers 60 may be managed by different entities. For example, the company that manages the first plurality of physical servers 40, the company that manages the second plurality of physical servers 50, and the company that manages the third plurality of physical servers 60 are different from each other. could be a company. The company that manages the plurality of second physical servers 50 may be a company that has been entrusted with the company that manages the plurality of first physical servers 40 . In addition, the company that manages the third plurality of physical servers 60 receives re-entrustment from the company that manages the second plurality of physical servers 50 , or manages the first plurality of physical servers 40 . It may be a company that has been entrusted with the company.

1 and 5 , the processor 41 of any one of the first plurality of physical servers 40 uses the profile information of the plurality of IoT devices 10-1, 10-2, ... , and 10-K) generate a plurality of virtual devices 11-1 to 11-M corresponding to each.

The processor 41 of any one of the first plurality of physical servers 40 is configured to operate in the plurality of virtual devices 11-1 to 11-M according to the importance of the plurality of virtual devices 11-1 to 11-M. ) apply a different security level to each.

The processor 41 of any one of the first plurality of physical servers 40 uses the received profile information for each of the plurality of IoT devices 10-1, 10-2, ..., and 10- K) A plurality of virtual devices 11-1 to 11-M corresponding to each are created.

The processor 41 of any one of the first plurality of physical servers 40 generates different encryption keys according to the applied security level for some of the plurality of virtual devices 11-1 to 11-M. Encrypt. For example, the processor 41 of any one of the first plurality of physical servers 40 is a virtual device 11-1 having a security level of 1 among the plurality of virtual devices 11-1 to 11-M, or 11-2) using the highest secret key (K _T ) to obtain a level 1 encryption key, and for a virtual device (11-3, 11-4, or 11-5) with a security level of 2, the level 1 A second-grade encryption key is generated using the encryption key and the shared secret key (K _P ). Similarly, the processor 41 of any one of the first plurality of physical servers 40 is a virtual device 11-6 having a security level of 3 among the plurality of virtual devices 11-1 to 11-M, or 11-7) using the second-level encryption key and the shared secret key (K _P ), the third-grade encryption key, and the above-mentioned for the virtual device (11-8, or 11-9) with a fourth-level security Using the 3rd level encryption key and the shared secret key (K _P ), the 4th level encryption key is shared with the 4th level encryption key for the virtual device (11-10, or 11-11) with the 5th level security level A level 5 encryption key is generated using the secret key (K _P ).

The first plurality of physical servers 40 may not generate encryption keys for all of the plurality of virtual devices 11-1 to 11-M, but may entrust some of them. That is, the first plurality of physical servers 40 excluding some (11-1 to 11-11) of the plurality of virtual devices (11-1 to 11-M) are the remaining virtual devices (eg, 11-12). For ~11-M), the second plurality of physical servers 50 or the third plurality of physical servers 60 may be entrusted to generate an encryption key suitable for each grade. At this time, any one processor 41 of the first plurality of physical servers 40 is any one processor 51 of the second plurality of physical servers 50 and a plurality of virtual devices 11-1 to 11-M), the entrustment request signal may be transmitted to generate an encryption key for the remaining virtual devices (eg, 11-12 to 11-M) except for some (11-1 to 11-11). Any one processor 41 of the first plurality of physical servers 40 transmits profile information for the remaining virtual devices (eg, 11-12 to 11-M) to the second plurality of physical servers 50 . It can be transmitted to any one of the processors 51 of The profile information includes type information, location information, ID, or operation information of the IoT device 10-1, 10-2, ..., or 10-K. The ID included in the profile information is used to generate an encryption key. Each of the plurality of IoT devices 10-1 to 10-K transmits respective profile information to any one processor 41 of the first plurality of physical servers 40 through the network 101 send.

In addition, the processor 41 of any one of the first plurality of physical servers 40 is the remaining virtual devices (eg, 11-12 to 11-M) to be generated by the second plurality of physical servers 50 . Any one processor of the encryption key (eg, grade 2) and the shared secret key (K _P ) of a grade higher than the highest security grade (eg, grade 3) among the second plurality of physical servers (50) (51).

Any one of the processors 51 of the second plurality of physical servers 50 receives the entrustment request signal from any one of the processors 41 of the first plurality of physical servers 40, the remaining virtual devices (eg, , 11-12 to 11-M), the highest security level (eg, 11-12 to 11-M) among the remaining virtual devices (eg, 11-12 to 11-M) to be generated by the second plurality of physical servers 50 , an encryption key of a grade (eg, grade 2) higher than grade 3), and a shared secret key (K _P ) Can be received from any one of the processors 41 of the first plurality of physical servers 40 there is.

Any one of the processors 51 of the second plurality of physical servers 50 receives the shared secret key (K _P ), and another encryption method (eg, adding another character) for the shared secret key (K _P ) , or change the character position) to generate a new shared secret key (K _P ') different from the shared secret key (K _P ). The other encryption method is also known to the first plurality of physical servers 40 .

The processor 51 of any one of the second plurality of physical servers 50 generates different encryption keys according to the applied security level, and the remaining virtual devices among the plurality of virtual devices 11-1 to 11-M Encrypt for the fields (eg, 11-12 ~ 11-M). For example, the processor 51 of any one of the second plurality of physical servers 50 is a virtual device 11-12 having a security level of 3 among the remaining virtual devices (eg, 11-12 to 11-M). or 11-13), the remaining virtual devices to be created by the second plurality of physical servers 50 received from any one of the processors 41 of the first plurality of physical servers 40 (eg, 11 -12~11-M), using the encryption key of one level higher (eg, level 2) than the highest security level (eg, level 3) and the new shared secret key (K _P '), the third level encryption key , a level 4 encryption key is generated using the level 3 encryption key and the new shared secret key (K _P ') for the virtual device 11-14 or 11-15 of which the security level is level 4. Similarly, the processor 51 of any one of the second plurality of physical servers 50 is a virtual device 11-16 having a security level of 5 among the remaining virtual devices (eg, 11-12 to 11-M). Alternatively, for 11-17), a 5-grade encryption key is generated using the 4-level encryption key and the new shared secret key (K _P ').

In this case, a client (eg, 20-4, 20-5, 20-6, or 20-7) that can access the virtual devices 11-3 to 11-5 of a specific grade (eg, grade 2) is a specific It is possible to access the virtual devices 11-1 to 11-11 encrypted by encryption keys generated by the first physical servers 50 of a grade (eg, grade 2) or lower. In addition, clients (eg, 20-4, 20-5, 20-6, or 20-7) that can access virtual devices 11-3 to 11-5 of a specific class (eg, rank 2) are specific It is possible to access the virtual devices 11-12 to 11-17 encrypted by the encryption keys generated by the second physical servers 50 of a grade (eg, grade 2) or lower. However, a client (eg, 20-4, 20-5, 20-6, or 20-7) that can access the virtual devices 11-3 to 11-5 of a specific grade (eg, grade 2) is You cannot access virtual devices (eg, 11-1, or 11-2) of a higher grade (level 1) than a certain grade (eg, grade 2).

In addition, clients (eg, 20-10, or 20-11) that can access virtual devices 11-8 to 11-9 of a specific grade (eg, grade 4) are less than or equal to a specific grade (eg, grade 4) It is possible to access the virtual devices 11-8 to 1-9 encrypted by the encryption keys generated by the first physical servers 40 of In addition, clients (eg, 20-12, or 20-13) that can access virtual devices 11-14 to 11-15 of a specific grade (eg, grade 4) are lower than or equal to a specific grade (eg, grade 4) It is possible to access the virtual devices 11-14 to 11-15 encrypted by the encryption keys generated by the second physical servers 50 of However, clients (eg, 20-12, or 20-13) that can access virtual devices 11-14 to 11-15 of a specific grade (eg, grade 4) are lower than or equal to a specific grade (eg, grade 4) It is impossible to access the virtual devices 11-8 to 1-9 encrypted by the encryption keys generated by the first physical servers 40 of This is because the shared secret key (K _P ) and the new shared secret key (K _P ') are different from each other, and thus the generated encryption keys are also different.

The second plurality of physical servers 50 do not generate encryption keys for all of the remaining virtual devices 11-12 to 11-M, and may give re-entrustment for some. That is, the first plurality of physical servers 40 excluding some (11-1 to 11-11) of the plurality of virtual devices (11-1 to 11-M) are the remaining virtual devices (eg, 11-12). For ~11-M), the second plurality of physical servers 50 or the third plurality of physical servers 60 may be entrusted to generate an encryption key suitable for each grade. At this time, any one processor 51 of the second plurality of physical servers 50 is any one processor 61 of the third plurality of physical servers 60 and the other virtual devices (eg, 11- 12 to 11-M), except for some (11-12 to 11-17), may transmit a re-entrustment request signal for encryption key generation to the remaining virtual devices (eg, 11-18 to 11-19). One processor 51 of the second plurality of physical servers 50 transmits profile information for the remaining virtual devices (eg, 11-18 to 11-19) to the third plurality of physical servers 60 . It can be transmitted to any one of the processors 61 of

In addition, the processor 51 of any one of the second plurality of physical servers 50 is the remaining virtual devices to be generated by the plurality of third physical servers 60 (eg, 11-18 to 11-19). Any one of the third plurality of physical servers 60 with an encryption key (eg, grade 4) of a grade higher than the highest security grade (eg, grade 5) and a new shared secret key (K _P ') to the processor 61 of

Any one of the processor 61 of the third plurality of physical servers 60 receives the entrustment request signal from any one of the processors 51 of the second plurality of physical servers 50, the remaining virtual devices (eg, , 11-18 to 11-19), the highest security level (eg, 11-18 to 11-19) among the remaining virtual devices (eg, 11-18 to 11-19) to be generated by the third plurality of physical servers 60 , a level higher than the level 5), and a new shared secret key (K _P ') is received from any one of the processors 51 of the second plurality of physical servers 50 (eg, level 4). can do.

Any one of the processors 61 of the third plurality of physical servers 60 receives the new shared secret key K _P ′, and uses another encryption method (eg, K _P ′) for the new shared secret key K P ′. , adding another character, or changing the character position) to generate a second new shared secret key (K _P '') different from the new shared secret key (K _P '). The other encryption method is also known to the second plurality of physical servers 50 .

The processor 61 of any one of the third plurality of physical servers 60 encrypts the remaining virtual devices (eg, 11-18 to 11-19) by generating different encryption keys according to the applied security level. do. For example, the processor 61 of any one of the plurality of third physical servers 60 is a virtual device 11-18, a security level of 5 among the remaining virtual devices (eg, 11-18 to 11-19). or 11-19), the remaining virtual devices to be created by the third plurality of physical servers 60 received from any one of the processors 51 of the second plurality of physical servers 50 (eg, 11 -18, 11-19) using an encryption key of a higher level (eg, level 4) than the highest security level (eg, level 5) and a second new shared secret key (K _P '') Generate an encryption key.

The first plurality of physical servers 40 entrust the second plurality of physical servers 50 , and the second plurality of physical servers 50 re-entrust the third plurality of physical servers 60 . It is possible to distribute the concentration of the load on each of the plurality of physical servers 40 , 50 , or 60 . In addition, in the virtual devices 11-1 to 11-11 encrypted using the encryption key generated by the physical servers 40 using the encryption key generated by the physical servers 50 or 60, Because access is not possible, security can be strengthened.

A client (eg, 20-18, or 20-19) that can access the virtual devices 11-18 to 11-19 of a specific grade (eg, grade 5) is less than or equal to a specific grade (eg, grade 5) 3 It is possible to access the virtual devices 11-12 to 11-17 encrypted by the encryption keys generated by the physical servers 60. However, clients (eg, 20-18, or 20-19) that can access virtual devices 11-18 to 11-19 of a specific grade (eg, grade 5) are less than or equal to a specific grade (eg, grade 5) It is impossible to access the virtual devices 11-16 to 1-17 encrypted by the encryption keys generated by the second physical servers 50 of This is because the new shared secret key (K _P ') and the second new shared secret key (K _P '') are different from each other.

Although the present invention has been described with reference to an embodiment shown in the drawings, this is merely exemplary, and those of ordinary skill in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Accordingly, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

100: cloud-based IoT device control system;
10-1, 10-2, ..., or 10-K: IoT device;
20-1, 20-2, ..., or 20-N: client;
30: cloud service;
101: network;
40, 50, or 60: physical server;
11-1, 11-2, ..., or 11-M: virtual device;

Claims (5)

In order to control a plurality of IoT devices, a cloud service is provided through a plurality of physical servers, wherein each of the plurality of physical servers includes a processor and a memory, in the cloud-based IoT device control method,
receiving, by the processor, respective profile information from each of a plurality of IoT devices;
generating, by the processor, a plurality of virtual devices corresponding to each of the plurality of IoT devices by using each of the received profile information;
connecting, by the processor, a plurality of clients and the plurality of virtual devices to each other according to configuration signals of the plurality of clients;
applying, by the processor, different security levels to each of the plurality of virtual devices according to the importance of the plurality of virtual devices; and
and the processor encrypts each of the plurality of virtual devices by generating different encryption keys according to the applied security level. The method of claim 1, wherein the smaller the number of the applied security level, the stronger the security of the plurality of virtual devices,
A cloud-based IoT device control method in which the different encryption keys of the plurality of virtual devices are sequentially generated from a number having a small applied security level. The method of claim 2, wherein when the security level applied to any one of the plurality of virtual devices is level 1, the processor allows only clients that can access the level 1 virtual device with respect to the virtual device to which the level 1 is applied. Using the hash function result value of the shared highest secret key and the hash function result value of the ID of the virtual device to which the 1st grade is applied, a first-class encryption key is generated,
When the security level applied to another one of the plurality of virtual devices is level n, the processor performs a hash of the encryption key of level (n-1) with respect to the virtual device to which the level n (n is a natural number greater than or equal to 2) is applied. A cloud-based IoT device control method for generating an n-grade encryption key using a function result value and a hash function result value of the ID of the virtual device to which the n-grade is applied. The method of claim 3, wherein a client capable of accessing the virtual device of the first class can access virtual devices of a lower class than the first class,
A client capable of accessing the second-class virtual device can access virtual devices of a lower level than the second-grade virtual device, but cannot access the first-class virtual device, which is a virtual device higher than the second-class, cloud-based IoT device control method. a processor that executes instructions; and
a memory for storing the instructions;
The commands are
Receives respective profile information from each of a plurality of IoT devices, generates a plurality of virtual devices corresponding to each of the plurality of IoT devices by using the received respective profile information, and provides setting signals of a plurality of clients connects the plurality of clients and the plurality of virtual devices to each other according to It is implemented to encrypt each of the plurality of virtual devices by generating different encryption keys,
The processor and the memory are implemented in a physical server,
A cloud-based IoT device control system in which a cloud service is provided through the physical server.

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