KR20210123575A - Termimal, server, lightweight authentication method using the same - Google Patents

Abstract

The present invention relates to a method for a central management server including at least one processor to authenticate a device in conjunction with the device, which includes the steps of: receiving, from the device, identification information and a password, and ID information including a pseudo identifier generated by a first random number, and the first random number to calculate authentication parameters for authenticating the device; transmitting the calculated authentication parameters to the device without storing them in a memory; authenticating the device based on received authentication request information when receiving, from the device, authentication request information including at least one of the pseudo identifier, a specific authentication parameter, and a plurality of verification parameters calculated based on the authentication parameters; and updating the authentication parameters and transmits them to the device, if authentication is successful.

Description

Device and lightweight authentication method using the same {TERMIMAL, SERVER, LIGHTWEIGHT AUTHENTICATION METHOD USING THE SAME}

The present invention relates to a device and a lightweight authentication method using the same.

Various authentication methods are used for secure communication and data exchange between a user and a user, between a user and a device, and between a device and a device.

A general authentication method registers the user's own identity information and key secret parameters in a central management system that the user trusts in advance. The central management system manages information registered by the user as a verification table, and authenticates the user and the device.

However, when a general authentication method is used, important information is collectively managed in the verification table of the central management system. Therefore, if the verification table is exposed to a malicious attacker, not only the privacy of the user but also the safety of the entire system may be violated.

In order to solve this problem, various authentication techniques that do not store the verification table in the central management system are being studied.

Central management systems are pre-registered with a top-level Trusted Third Party (TTP) certification authority that is assumed to be secure, and TTP stores/manages user data or provides authentication services based on public keys. However, even in these methods, when the verification table of the highest TTP is exposed by an insider, problems such as problems in the central management system may occur.

In addition, the public key-based authentication method has a problem in that it cannot operate efficiently in a low-spec device such as a sensor. Therefore, in consideration of the amount of computation of the device, the device should manage the user's identity information and key secret parameters by itself to be efficiently utilized for authentication.

An object of the present invention is to provide a device in which the device directly manages important information without storing user identity information and important parameters in a central management system, and a lightweight authentication method using the same.

As a method in which a central management server, which is a feature of the present invention for achieving the technical problem of the present invention, works with the device to authenticate the device,

Calculating a plurality of authentication parameters for authenticating the device upon receiving identity information including a pseudo identifier and a first random number from the device; transmitting, upon receiving from the device authentication request information including the pseudo identifier, any one of the plurality of authentication parameters, and at least one of the plurality of verification parameters, based on the received authentication request information authenticating the device, and updating and transmitting the authentication parameters to the device after authentication.

Before calculating the authentication parameter, the method may include generating a master key for generating or processing the plurality of authentication parameters.

Each of the plurality of authentication parameters may be calculated by performing a hash operation and an exclusive-OR operation on at least one of the pseudo identifier, the first random number, and the master key received from the device.

The calculating of the authentication parameters includes calculating a first authentication parameter using the pseudo-identifier and the master key, calculating a second authentication parameter using the first authentication parameter and the first random number, A third authentication parameter may be calculated using the first random number, the pseudo identifier, and the master key.

The authentication request information includes a time stamp generated by the device,

The authenticating of the device may include evaluating the validity of the time stamp, verifying the first random number from the second authentication parameter, based on the master key, the pseudo identifier, and the confirmed first random number. The method may include calculating a fourth authentication parameter, and maintaining a session with the device when a specific verification parameter included in the authentication request information received from the device matches the fourth authentication parameter.

The transmitting to the device may include calculating a plurality of random numbers for updating an authentication parameter, updating the authentication parameters using the random numbers, and a plurality of verification values calculated based on the updated authentication parameters. and transmitting them to the device.

As a method for authenticating a device including at least one processor, which is another feature of the present invention for achieving the technical problem of the present invention, in conjunction with a central management server,

Generating identity information and registering the device itself in the central management server, when receiving a plurality of authentication parameters for authentication from the central management server, recalculating the plurality of authentication parameters and storing the authentication parameters in a memory, the generation Reading authentication parameters stored in the memory by using one identity information to calculate a verification parameter, transmitting an authentication request signal including at least one of the verification parameter and the authentication parameter to the central management server, and the and re-calculating and storing the updated authentication parameters according to whether authentication is performed from the central management server.

The step of registering with the central management server includes generating an identity identifier and password, generating a first random number and a second random number, and generating a pseudo identifier using the identity identifier and password and the first random number. Calculating, and transmitting the identity information including the pseudo identifier and the first random number to the central management server.

The pseudo identifier may be calculated by a hash operation and an exclusive OR operation.

The storing in the memory may include: receiving the plurality of authentication parameters calculated using at least one of the pseudo identifier, the master key generated by the central management server, and the first random number from the central management server and re-calculating the plurality of authentication parameters using at least one of the second random number, the identity identifier, and the password.

The calculating of the verification parameter may include: receiving identification information; calculating a user information verification parameter using the identification identifier, the password, and the second random number; and based on the calculated user information verification parameter It may include verifying the received identity information.

The transmitting to the central management server may include calculating verification information using at least one of the plurality of authentication parameters, an identity identifier, a password, and at least one of the second random number.

The re-calculating and storing may include calculating a session key to be used for a preset period and performing key agreement.

As a device for performing an authentication procedure in conjunction with a central management server, which is another feature of the present invention for achieving the technical problem of the present invention,

A processor, and a memory for loading a computer program executed by the processor and storing a plurality of authentication parameters generated by the central management server and identity information generated by the processor, the processor comprising: An identity identifier and password to be transmitted to the central management server are generated, the authentication parameters received from the central management server are re-calculated, and the re-calculated authentication parameters are stored in the memory.

The processor may recalculate the authentication parameters using a hash operation and an exclusive-OR operation.

According to an embodiment of the present invention, the device may use the authentication service by managing the identity information of the user or the device itself and important parameters for authentication in the central management system, without storing in the central management system.

In addition, since authentication is performed using hash and XOR operations, it can be efficiently utilized in environments using low-spec devices such as the Internet of Things.

In addition, since the device manages authentication parameters by itself, it can be applied to various environments and utilized to guarantee privacy, improve security and efficiency.

1 is an exemplary diagram of an environment to which a lightweight authentication method according to an embodiment of the present invention can be applied.
2 is a flowchart of a device registration method according to an embodiment of the present invention.
3 is a flowchart of an authentication method according to an embodiment of the present invention.
4 is a diagram illustrating a computer system according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, the embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement them. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part is "connected" with another part, this includes not only the case of being "directly connected" but also the case of being "electrically connected" with another element interposed therebetween. . In addition, when a part "includes" a certain component, this means that other components may be further included, rather than excluding other components, unless otherwise stated.

Hereinafter, with reference to the drawings, a device according to an embodiment of the present invention, a light-weight authentication method using the same, and a key agreement method will be described in detail.

1 is an exemplary diagram of an environment to which a lightweight authentication method according to an embodiment of the present invention can be applied.

As shown in FIG. 1 , in the Internet environment according to an embodiment of the present invention, various devices and sensors 10 - 1 to 10 - 3 are connected to the Internet 30 through a gateway 20 . In addition, the IoT device (eg, a smartphone, an IP camera, etc.) is directly connected to the Internet 20 through a wired or wireless network, and through interworking with a service providing server (or cloud server, etc.) 40 . Various types of services are provided to users.

In order to safely provide an Internet of Things environment-based service to a user, the Internet of Things device performs authentication in conjunction with a central management system. In the embodiment of the present invention, the central management system is referred to as a 'central management server 100', and for convenience of description, authentication between the IoT device and the central management server 100 will be described as an example. In addition, although the central management server 100 is illustrated as an independent component, the central management server 100 for authentication may be included in the service providing server 40 .

When authentication between the central management server 100 and the IoT device 200 is successfully completed, a secure session is created between the service providing server 40 and the IoT device 200 . And, by encrypting the data transmitted and received using the session key, confidentiality can be imparted to the data.

Here, the central management server 100 is a server included in the authentication system (not shown), and a plurality of Internet of Things devices 200 are connected through a network.

The central management server 100 _{defines a master key (K ser} ) for processing authentication parameters, and performs an initial setting procedure so that a plurality of IoT devices 200 are connected. Here, the initial setting procedure performed by the central management server 100 is already known, and detailed description will be omitted in the embodiment of the present invention.

The central management server 100 calculates important parameters for authentication and transmits them to the IoT device 200 . At this time, the calculated important parameters are not stored in the central management server 100 .

The IoT devices 200 generate an identity identifier (ID _U ) and a password (PW) for identifying themselves, and a first random number (r) and a second random number (k) that are two random numbers. In addition, each IoT device 200 generates a pseudo ID (PID) and transmits it to the central management server 100 together with the first random number r.

The IoT devices 200 calculate the original information verification parameters (V, C) for verifying the input identity information and store the calculated parameters in the memory. Then, the IoT device 200 recalculates the authentication parameters (S, A _sn , B _sn ) transmitted from the central management server 100 so that they are not exposed to the outside, and then stores them in the memory. Then, by using the authentication parameters stored in the memory, authentication is performed with the central management server 100 through an open channel or key agreement is executed.

In such a communication environment, the method of registering the Internet of Things device 200 to the central management server 100 and performing an authentication procedure between the registered Internet of Things device 200 and the central management server 100 is illustrated in FIG. 2 and It will be described in detail with reference to FIG. 3 .

2 is a flowchart of a device registration method according to an embodiment of the present invention.

2, the central management server 100 _{defines a master key (K ser} ) for generating or processing authentication parameters, and performs an initial setting operation (S100). Here, a method for the central management server 100 to define a master key and a method for performing an initial setting operation are already known, and detailed description thereof will be omitted in the embodiment of the present invention.

The IoT device 200 generates an identity identifier (ID _U ) and a password (PW _U ). The identity identifier and password may be generated by the IoT device 200 or may be received as input from the outside. In the embodiment of the present invention, the generation of identity information including an identity identifier and a password in the IoT device 200 will be described as an example.

When the identity information is generated, the IoT device 200 generates two random numbers, a first random number (r) and a second random number (k) ( S110 ). The first of the two random numbers is used to calculate the pseudo-identifier. And, the second random number is used to re-calculate the authentication parameters received from the central management server 100, which will be described later.

The IoT device 200 calculates a pseudo identifier (PID: Pusedo ID) using the identity identifier, the password, and the first random number ( S120 ). In order for the IoT device 200 to calculate a pseudo identifier (PID) in step S120, the following Equation 1 is used.

The IoT device 200 transmits device identity information including the pseudo identifier calculated in step S120 and the first random number r used to calculate the pseudo identifier to the central management server 100 through a secure communication channel. do (S130). Here, the secure communication channel is determined according to the server's policy, and one of various methods (eg, written submission or data submission through TLS protocol) may be selected and used.

The central management server 100 calculates a plurality of authentication parameters for authenticating the IoT device 200 based on the device identity information received in step S130 (S140). In the embodiment of the present invention, calculation of three authentication parameters through Equation 2 will be described as an example.

The central management server 100 obtains the first authentication parameter (S) by performing a hash operation after concatenating the pseudo identifier and the master key. Then, the central management server 100 obtains _{the second authentication parameter A SN} by performing an exclusive OR operation on the first random number r and the first authentication parameter S generated by the IoT device 200 .

The central management server 100 obtains the third authentication parameter, B _SN, by performing a hash operation on the first random number (r), the pseudo identifier (PID), and the master key (K _{ser ) after the concatenation operation.} Here, the SN refers to the IoT device 200 that has requested authentication.

When the plurality of authentication parameters are calculated in this way, the central management server 100 transmits the calculated plurality of authentication parameters to the IoT device 200 (S150). At this time, the central management server 100 does not store any authentication parameters in the memory in the central management server 100 .

The IoT device 200 calculates the identity information verification parameters V and C in order to generate a verification parameter that verifies whether the identity information is properly generated or input later. The calculated identity information verification parameter is stored in a memory in the IoT device 200 (S160). When the IoT device 200 calculates the identity information verification parameter, the following Equation 3 is used.

The IoT device 200 calculates a first identity information verification parameter, V, by performing a concatenation operation and a hash operation on the identity identifier, the password, and the second random number (k) generated in step S110. Then, the IoT device 200 calculates C, which is a second identity information verification parameter, by performing an exclusive-OR operation on the hash value of the connection-calculated identity identifier and password and the second random number (k).

After calculating the identity information verification parameters in step S160, the IoT device 200 recalculates the plurality of authentication parameters received from the central management server 100 in step S150 and stores them in the memory (S170). In this case, the IoT device 200 recalculates the authentication parameters using Equation 4 below.

이고,

이다. here,

ego,

am.

Here, SPW is a parameter created not to store the user's password in the memory as it is, and S' is a parameter created not to store the verification parameter S generated by the server as it is. In the case of S', it is updated every subsequent session for security.

As described above, when the central management server 100 is initially set and the IoT device 200 is registered with the central management server 100, authentication and key agreement are performed through the open channel according to the procedure of FIG. 3 . .

3 is a flowchart of an authentication method according to an embodiment of the present invention.

As shown in FIG. 3 , the IoT device 200 generates an identity identifier (ID _U ) and a password (PW _U ) when inputting (S200), a temporary secret parameter (n1) and a time stamp (t1) ( S201). Since the method of generating the temporary secret parameter and the time stamp by the IoT device 200 may be performed in various ways, a detailed description thereof will be omitted in the embodiment of the present invention.

The IoT device 200 calculates the second random number k, SPW, and two hash values as shown in Equation 5 below (S202).

The IoT device 200 checks the re-computation parameters stored in the memory in the registration procedure of FIG. 2 , that is, the pseudo identifier, B _SN , and A _SN ( S203 ), and includes a plurality of verification parameters ( S1 and S2 ) and The identity information verification parameter (V') is calculated (S204). Here, the verification parameters S1 and S2 and S3 to S6 to be described later are parameters for verifying whether the central management server 100 and the IoT device 200 are generating correct values with each other.

In step S204, the verification parameters and the identity information verification parameters are calculated as in Equation 6 below.

The IoT device 200 compares the identity information verification parameter (V') calculated in step S204 with the stored identity information verification parameter (V) and verifies whether the identity information input in step S200 is correct information (S205). ). If the two parameters do not match, the IoT device 200 terminates the authentication procedure.

However, if the two parameters match, the IoT device 200 sends a plurality of verification parameters S1 and S2 to the central management server 100, a pseudo identifier (PID), and a second authentication parameter A _SN and a time stamp ( t1) and transmits an authentication request signal (S206).

) 유효성 검증에 성공한 것으로 확인한다.The central management server 100 verifies the validity of the time stamp received in step S206 (S207). There are various methods for the central management server 100 to verify the validity of the time stamp, and in an embodiment of the present invention, the difference value obtained by subtracting the time of the time stamp from the time received in step 206 from the current time is a preset threshold time If shorter (

) to confirm that the validation was successful.

The central management server 100 calculates the first authentication parameter S of the IoT device 200 using its master key (S208). Then, the first random number r is _{checked from the second authentication parameter A SN} (S209). The central management server 100 calculates the first authentication parameter S using the following Equations 7 and 8 and confirms the first random number r.

The central management server 100 calculates a plurality of parameters B _SN , n1 , S2 ( S210 ), and the second verification parameter S2 received from the IoT device 200 matches S2 among the plurality of calculated parameters It is checked whether or not (S211). If they do not match, the session is terminated (S212). Here, the central management server 100 calculates a plurality of parameters using the following Equation (9).

로 계산된다.The central management server 100 generates a timestamp t2 ^{, calculates two random numbers n2, r +} , and uses the two random numbers to authenticate the existing IoT device 200 A _SN , B _SN , S , and the pseudo identifier is updated (S213). At this time, of the two random numbers, r ⁺ is

is calculated as

Here, a parameter with * is a random number transmitted by the IoT device 200 , and a parameter + means a parameter newly generated by the central management server 100 for update. That is, parameters with + mean updated values.

And, the values of parameters with **, which will be described later, are values transmitted by the central management server 100 to the IoT device 200 and mean values to be verified by the IoT device 200 . For example, if the r** value transmitted by the central management server 100 is not correct, it may be confirmed that the wrong value is transmitted because the S6 verification parameter does not match.

Then, the central management server 100 calculates the following parameters through Equation 10, and then transmits the calculated values S3, S4, S5, S6, and t2 (S213).

와 같이 계산하여 올바른 값이 전송되었는지 확인한다(S216, S217). 사물 인터넷 디바이스(200)는 수신한 파라미터(S3, S4, S5, S6, t2)로부터 갱신된 인증 파라미터

를 찾아온다(S218). 즉, 사물 인터넷 디바이스(200)가 올바른 디바이스라면, 중앙 관리 서버(100)가 전송한 파라미터 S4, S5로부터 S+, B_SN+값을 계산하고, A_SN+, PID+ 값을 생성할 수 있다.The IoT device 200 verifies the validity of the time stamp t2 received in step S213 (S215), _{and calculates n2, B SN} , y, and a pseudo-identifier. And after checking the _{S, B SN} stored in the memory,

It is calculated as shown and checked whether the correct value is transmitted (S216, S217). The IoT device 200 receives an authentication parameter updated from the received parameters (S3, S4, S5, S6, t2).

comes to (S218). That is, if the IoT device 200 is a correct device, S+ and B _SN + values may be calculated _{from the parameters S4 and S5 transmitted by the central management server 100, and A SN} + and PID+ values may be generated.

)을 저장한다(S219). 여기서, 갱신된 인증 파라미터는 다음 수학식 11과 같이 재연산된다.The IoT device 200 recalculates the updated authentication parameters, and recalculates the recalculated updated authentication parameters (

) is stored (S219). Here, the updated authentication parameter is recalculated as shown in Equation 11 below.

), 키 합의를 수행한다(S220). 이와 같이 중앙 관리 서버(100)가 생성하는 모든 사용자의 파라미터들은 단계 마지막에 갱신되므로, 불추적성이 보장된다.Finally, the IoT device 200 and the central management server 100 calculate a session key (Ks) to be used for a certain period of time (

), perform key agreement (S220). In this way, all user parameters generated by the central management server 100 are updated at the end of the step, so traceability is guaranteed.

4 is a diagram illustrating a computer system according to an embodiment of the present invention.

The central management server 100 according to an embodiment of the present invention may be implemented as a computer system 300 as shown in FIG. 4 . In addition, each component of the IoT device 200 may be implemented as the computer system 300 shown in FIG. 4 .

The computer system 300 includes at least one of a processor 310 , a memory 330 , a user interface input device 340 , a user interface output device 350 , and a storage device 360 communicating via a bus 320 . may include

The processor 310 may be a central processing unit (CPU) or a semiconductor device that executes instructions stored in the memory 330 or the storage device 360 . The processor 310 may be configured to implement the functions and methods described with reference to FIGS. 1 to 3 .

The memory 330 and the storage device 360 may include various types of volatile or non-volatile storage media. For example, the memory 330 may include a read only memory (ROM) 331 and a random access memory (RAM) 332 . In an embodiment of the present invention, the memory 330 may be located inside or outside the processor 310 , and the memory 330 may be connected to the processor 310 through various known means.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improved forms of the present invention are also provided by those skilled in the art using the basic concept of the present invention as defined in the following claims. is within the scope of the right.

Claims (15)

As a method for the central management server to authenticate the device in conjunction with the device,
upon receiving identity information including a pseudo identifier and a first random number from the device, calculating a plurality of authentication parameters for authenticating the device;
transmitting the calculated plurality of authentication parameters to the device without storing it in a memory;
When authentication request information including at least one of the pseudo identifier, any one of the plurality of authentication parameters, and at least one of the plurality of verification parameters is received from the device, the device is authenticated based on the received authentication request information step, and
After authentication, updating the authentication parameters and transmitting them to the device
Including, authentication method. According to claim 1,
Before calculating the authentication parameter,
generating a master key for generating or processing the plurality of authentication parameters;
Including, authentication method. According to claim 1,
Each of the plurality of authentication parameters calculates at least one of the pseudo identifier, the first random number, and the master key received from the device by a hash operation and an exclusive-OR operation. 4. The method of claim 3,
Calculating the authentication parameters comprises:
calculating a first authentication parameter using the pseudo identifier and the master key;
calculating a second authentication parameter using the first authentication parameter and the first random number;
and calculating a third authentication parameter by using the first random number, the pseudo identifier, and the master key. 5. The method of claim 4,
The authentication request information includes a time stamp generated by the device,
The step of authenticating the device,
evaluating the validity of the timestamp;
identifying the first random number from the second authentication parameter;
calculating a fourth authentication parameter based on the master key, the pseudo identifier, and the confirmed first random number; and
maintaining a session with the device when a specific verification parameter included in the authentication request information received from the device matches the fourth authentication parameter;
Including, authentication method. According to claim 1,
Transmitting to the device comprises:
calculating a plurality of random numbers for updating the authentication parameter;
updating the authentication parameters using the random numbers; and
Transmitting a plurality of verification values calculated based on the updated authentication parameters to the device
Including, authentication method. As a method for authenticating a device including at least one processor in conjunction with a central management server,
generating identity information and registering the device itself in the central management server;
Upon receiving a plurality of authentication parameters for authentication from the central management server, recalculating the plurality of authentication parameters and storing the plurality of authentication parameters in a memory;
Calculating verification parameters by reading authentication parameters stored in the memory using the generated identity information;
transmitting an authentication request signal including at least one of the verification parameter and the authentication parameter to the central management server; and
Re-calculating and storing the updated authentication parameters according to whether the authentication is performed from the central management server
Including, authentication method. 8. The method of claim 7,
The step of registering with the central management server,
generating an identity identifier and password;
generating a first random number and a second random number;
calculating a pseudo-identifier using the identity identifier and password and the first random number; and
transmitting the identity information including the pseudo identifier and the first random number to the central management server
Including, authentication method. 9. The method of claim 8,
and the pseudo-identifier is calculated by a hash operation and an exclusive-OR operation. 10. The method of claim 9,
The step of storing in the memory,
Receiving the plurality of authentication parameters calculated using at least one of the pseudo identifier, the master key generated by the central management server, and the first random number from the central management server, and
re-calculating the plurality of authentication parameters using at least one of the second random number, the identity identifier, and a password
Including, authentication method. 11. The method of claim 10,
Calculating the verification parameter comprises:
receiving identification information;
calculating a user information verification parameter using the identity identifier, the password, and the second random number; and
verifying the received identity information based on the calculated user information verification parameter
Including, authentication method. 12. The method of claim 11,
The step of transmitting to the central management server,
calculating verification information using at least one of the plurality of authentication parameters, an identity identifier, a password, and at least one of the second random number;
Including, authentication method. 13. The method of claim 12,
The step of re-calculating and storing is,
Performing key agreement by calculating a session key to be used for a preset period
Including, authentication method. A device that performs an authentication procedure in conjunction with a central management server, comprising:
processor, and
A memory for loading a computer program executed by the processor and storing a plurality of authentication parameters generated by the central management server and identity information generated by the processor
including,
The processor is
A device for generating an identity identifier and password to be transmitted to the central management server, re-calculating the authentication parameters received from the central management server, and storing the re-calculated authentication parameters in the memory. 15. The method of claim 14,
The processor is
A device for recomputing the authentication parameters with a hash operation and an exclusive-OR operation.

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