KR101525888B1 - Device and method creating one time password using physically unclonable function - Google Patents

Abstract

The present invention relates to an OTP generator for authenticating a user in an electronic financial transaction system, in which an OTP generator receives a challenge value (C ₀ ) from an external server, and a PUF (Physically Unclonable Function) When generating a response value (R ₀₎ corresponding to _zero), and generates a password OTP using the time alignment information and the response value (R _0). This OTP generator has the effect of preventing the attacker from restoring any information because the desired information is encrypted by using the response value of the PUF as the secret key.

Description

Technical Field [0001] The present invention relates to an apparatus and a method for generating an OTP using a PUF,

The present invention relates to an apparatus and method for generating an OTP using a PUF, and more particularly, to a method for generating a password using an OTP generator, an authentication server, and an OTP generator for authenticating a user in an electronic financial transaction system.

OTP (One Time Password) is a one-time password and is used as a secure authentication method in many ways. In particular, in the case of domestic electronic financial transactions, it provides secure electronic financial transactions by using it as an additional authentication factor to confirm the identity of the user.

However, as phishing and pharming attacks become more intelligent, various threats still exist in electronic financial transactions. Recently, attackers set a specific target as a target, collecting important personal information of the attacked person and causing monetary damages. In 2011, some systems that manufacture OTP generators called SecureIDs were hacked and information about OTP generators leaked. As a result, there were actions such as the recovery of SecureID products in Korea. There has been a continuing need to take measures to prevent these various threats.

OTP basically copes with this threat by generating random values using the advantages of the hash function, which is a unidirectional function. But attacks such as eavesdropping and social engineering still exist.

In Korea, a time synchronized OTP (Time Synchronized OTP) generator which is considered to be the most secure is used, which uses the same clock information between the server and the OTP generator.

However, as attacks become increasingly intelligent, a variety of attacks exist, especially if the attacker collects personal information against a specific target. Also, the possibility of replicating the OTP generator through hardware technology can not be overlooked either.

The time synchronization type OTP generator used in the financial transaction system confirms the identity of the user by checking whether the time clock information synchronized with each other between the server and the OTP generator coincide with each other.

However, if attackers collect information about security tokens and secret keys using various sophisticated social engineering and phishing attacks, they can generate the same OTP value. In other words, if we look at the algorithm that generates the OTP value, it is possible to generate the same OTP value if only the same input information is input because only the software method is used.

In this connection, Korean Patent Laid-Open No. 10-2010-0114775 (entitled: User-defined authentication system using OTP) describes a user authentication method using an OTP generator.

The present invention aims to overcome the limitations of the prior art which is vulnerable to security because an attacker can collect information on a security token and a secret key by using social engineering and phishing attacks and generate the same OTP value.

The present invention also attempts to overcome the limitations of the prior art which is vulnerable to security because a financial transaction is made only when a user's OTP is entered into the PC of the user other than the user's PC because the user does not use the transaction information.

The present invention also seeks to overcome the limitations of the prior art in which the authentication server stores and manages a fairly large amount of authentication information, resulting in a considerable load on the server.

The present invention also seeks to prevent damage to the financial transaction system due to eavesdropping attacks, message block attacks, replay attacks, spoofing attacks, and replication attacks.

As a technical means for achieving the above technical object, an OTP generator according to a first aspect of the present invention includes: a receiver for receiving a challenge value (C ₀ ) from an external server; A Physically Unclonable Fuction (PUF) module for generating a response value (R ₀ ) corresponding to the challenge value (C ₀ ); And a password generating unit for generating an OTP password using the time synchronization information and the response value (R ₀ ).

According to a second aspect of the present invention, there is provided a user authentication server including: a transmission unit for transmitting a challenge value (C ₀ ) to an OTP generator including a PUF module; A password generating unit for generating an OTP password using time synchronization information and a response value (R ₀ ) corresponding to the challenge value (C ₀ ); And an authentication unit for determining whether the OTP password input by the user and the OTP password generated by the password generator are identical, wherein the response value (R ₀ ) has been previously stored in the server, The user recognizes and inputs the information generated by the OTP generator.

According to a third aspect of the present invention, there is provided a method for generating an OTP secret key, the method comprising: receiving a challenge value (C ₀ ) from an external server; Generating a response value (R ₀ ) corresponding to the challenge value (C ₀ ) using the PUF module; Using the time alignment information and the response value (R ₀₎ includes generating a password OTP.

According to the above-mentioned object of the present invention, the attacker can not restore any information because the desired information is encrypted by using the response value of the PUF as a secret key. Therefore, attackers can not generate the same OTP value, which is security-safe.

In addition, according to the present invention, since the information of the challenge-response pair (CRP) is continuously updated, the authentication server stores and manages a considerably large amount of authentication information It is possible to overcome the limitations of the prior art in which a considerable load is placed on the server.

According to the present invention, since the CRP information exchanged between the OTP generator and the financial company server is updated each time, only the OTP of the user is inputted into the PC of the user other than the user's PC because the transaction information is not used Financial transactions have been made, which can overcome the limitations of the prior art which was vulnerable to security.

According to the present invention, there is no need to store the response value in the memory due to the characteristics of the PUF. Since the OTP generator generates a corresponding response value using the PUF whenever the challenge value is received from the server, the authentication server stores and manages a considerable amount of authentication information, thereby overcoming the limitations of the prior art can do.

FIG. 1 illustrates an overall financial transaction system including an OTP generator and a user authentication server according to the present invention.
2 illustrates an OTP generator according to an embodiment of the present invention.
3 illustrates a user authentication server according to an embodiment of the present invention.
4 illustrates a protocol between an OTP generator and a user authentication server.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "electrically connected" with another part in between . Also, when an element is referred to as "comprising ", it means that it can include other elements as well, without departing from the other elements unless specifically stated otherwise.

Throughout this specification, when an element is referred to as "including " an element, it is understood that the element may include other elements as well, without departing from the other elements unless specifically stated otherwise. The word " step (or step) "or" step "used to the extent that it is used throughout the specification does not mean" step for.

Throughout this specification, "PUF" is an abbreviation of Physically Unclonable Function, which means an IC circuit having characteristics that can not be physically duplicated. In other words, even if the attacker replicates the IC circuit of the PUF, it can not replicate the characteristics of the original PUF IC circuit. Therefore, even if the attacker replicates the PUF circuit by the random feature of the PUF, it is impossible to generate the output value of the same PUF.

Throughout this specification, "encoding" means encryption and encoding for security, and "decoding" means decryption. Unless otherwise specified herein, encoding has the same meaning as encryption, and decoding has the same meaning as decryption.

Throughout the present specification, "transaction information" is information on a financial transaction inputted from a user, and includes a method in which a user directly inputs a transaction information to a keypad or the like attached to the OTP generator, , A 3D bar code, a QR code, or the like, or a method in which a financial company and an OTP generator directly communicate with each other to input transaction information.

The bank Internet or smart banking service uses the OTP password as an additional password for secure electronic financial transactions. OTP passwords are updated every minute and can only be used once. In fact, if an OTP password is used in addition to the OTP password renewal cycle within one minute, the OTP password is updated and a warning message is displayed. The conventional OTP password generator generates the secret number using the secret key and the time synchronization information without using the transaction information. Since the transaction information is not used, the attacker could obtain the OTP password through MITB or eavesdropping attack.

In order to solve this problem, the conventional financial transaction system has prevented the same OTP password from being used at the same time several times. However, if an attacker enters the OTP password of the attacked user before the user and manipulates the transaction information, it may still cause a problem.

As a result of testing the conventional electronic financial transaction system, another PC connected to the banking system before inputting the OTP password for connecting to the banking system and transferring money to the PC. It is confirmed that another PC using the OTP password generated from the old PC tried to transfer the data and it is transferred normally. Therefore, it can be confirmed that the conventional OTP generator does not use transaction information, and it can be a threat element in electronic financial transaction.

The present invention adds a PUF to an OTP generator currently used in the financial sector to enhance the authentication of the OTP generator and the random characteristic of the OTP secret. It also prevents hardware duplication of the OTP generator by using the characteristics of the PUF.

The present invention also provides a method for performing authentication by comparing the CRP table information of the server with the CRP table transmitted by the user in the authentication method using the PUF or using a response value that is the output of the PUF as the secret key of the hash function. Make financial transactions happen.

However, the biggest problem in using PUF as an authentication technique is that a considerable amount of load is generated in the server since a large amount of CRP tables need to be stored and managed in the user authentication server. And provides an efficient method for managing the CRP table by updating the CRP. In addition, according to an embodiment of the present invention, an OTP password is generated by a standard cryptographic function, and a response value of a PUF is added to input information, thereby making it difficult for others to predict a password.

In the OTP-based financial transaction, the attacker collects personal information of a specific object and uses the information in combination to prevent another financial damage from occurring. Since the conventional financial transaction system does not use the transaction information and there is a threat to the transaction manipulation attack and the OTP password is generated by software, if the input information is acquired only, the same OTP password can be generated. However, To provide a more secure financial transaction by presenting a new financial transaction system.

The OTP generator according to an embodiment of the present invention can prevent the OTP generator from being copied by adding a hardware element called PUF. Next, we add the PUF response value to the input that generates the OTP password, which helps us to deal more securely. In order to implement the present invention, a communication channel for exchanging PUF messages and transaction information with each other is required between the OTP generator and the financial transaction system server. If the communication channel is limited, a user may directly use the OTP generator with a keypad, A method of inputting relevant information may be considered.

1 illustrates an overall financial transaction system including an OTP generator 100 and a user authentication server 200 according to the present invention. According to one embodiment of the present invention, the protocol used by the system uses a standard cryptographic function to safely protect the challenge-response pair (CRP) of the PUF, and uses HMAC Based hash function.

Figure 2 illustrates an OTP generator 100 in accordance with an embodiment of the present invention. The OTP generator 100 may further include a receiver 110, a PUF module 120, a password generator 130, and a transmitter 140, but may further include a decoder 115 and an encoder 150. Hereinafter, each component of the OTP generator 100 will be described.

The receiving unit 110 may receive the challenge value C ₀ from the external server 200 receiving the transaction information from the user but receive the second challenge value C ₁ to be used next from the external server 200 It is possible. At this time, the receiver 110 receives an ACK message indicating whether the OTP password received from the user is correct by the external server 200, and the ACK message includes a second challenge value C ₁ and a second response value R ₁ ). ≪ / RTI >

The invention serves to decode the decoding unit may further include (115), when the second challenge value (C ₁₎ the receiver is encoded received from the external server, the encoded second challenge value (C _1). In this case, according to an embodiment of the present invention, the secret key used for decoding may be the first response value (R ₀ ) obtained from the PUF module.

The PUF module 120 generates a response value R ₀ using the challenge value C ₀ and generates a second response value R ₁ when the receiver 110 receives the second challenge value C ₁ do.

The password generating unit 130 generates an OTP password. Information used to generate the password OTP is one including a time alignment information, and a response value (R _0), may further include a transaction information and a secret key.

The transmitter 140 transmits the second response value R ₁ to the external server 200 for use next time when the PUF module 120 generates the second response value R ₁ . Also, the transmitter 140 may transmit the OTP password generated by the password generator 130 to the user. This can be viewed as being output to the user terminal. According to an embodiment of the present invention, the transmitter may also transmit the first response value R ₀ to the external server 200. This is to judge whether the external server matches the OTP password inputted by the user with the OTP password generated by the external server based on the first response value (R ₀ ) or to compare with the response value of the CRP table of the external server to be.

The invention may further include an encoding unit 150, an encoding unit 150 using a standard encryption function encodes the response value R ₀ or the second response value R _1. At this time, the encoding unit 150 can encode using the encryption algorithm such as HMAC-SHA1, SEED, etc., and can use the response value R ₀ as the secret key. In addition, the encoding unit 150 may convert the second response value R ₁ using a hash function to check the error of the message. Hash function, for example, may be a function of the key may be a hash HMAC-based, password response values (R _0). At this time, the response value to be converted by the hash function comprises a response values encoded in the second response value (R ₁₎ or encoding portion 150 to be described below.

FIG. 3 illustrates an external user authentication server 200 according to an embodiment of the present invention. The external user authentication server 200 is a server that performs a user authentication to secure a secure transaction at the time of an electronic financial transaction such as a bank transfer at a bank or a securities company and is not necessarily limited to the server Lt; / RTI > Therefore, this external user authentication server is hereinafter referred to as "user authentication server 200 ".

The user authentication server 200 further includes an encoding unit 240 and a decoding unit 250 including a receiving unit 210, a transmitting unit 220, a password generating unit 230 and an authenticating unit 235 .

The receiving unit 210 receives the OTP password from the user. The OTP password inputted by the user is output by the user through the separate output means or the like and the OTP password generated by the OTP generator using the time synchronization information and the response value (R ₀ ) ). ≪ / RTI >

However, according to an embodiment of the present invention, the password generator 230 to be described later may receive a response value (R ₀ ) to be used for generating the OTP password from the OTP generator 100. When the transmitting unit 220 transmits the second challenge value C ₁ to be used next, the receiving unit 210 receives the second response value R ₁ corresponding to the second challenge value C ₁ from the OTP generator 100 .

The transmitting unit 220 transmits the challenge value C ₀ to the OTP generator 100 when the user requests authentication. However, the transmitting unit 220 may also transmit a second challenge value C ₁ to be used next time.

Also, when the OTP password is input from the user, the transmitter 220 can transmit an ACK message indicating that the inputted OTP password matches according to a result of the authentication unit 235 to be described later, the second one includes the challenge value (C ₁₎ to be used for, in response to the second value (R ₁₎ may further include.

The password generator 230 generates an OTP password using the time synchronization information and the response value R ₀ corresponding to the challenge value C ₀ and transmits the OTP password to the authentication unit 235. Information used to generate the password OTP may further include one including a time alignment information, and a response value (R ₀₎ private key, and transaction information. At this time, the response value R ₀ used by the password generating unit 230 may be received from the OTP generator, but may be stored in the user authentication server.

The authentication unit 235 determines whether the OTP password input by the user and the OTP password generated by the password generation unit 230 coincide with each other.

In accordance with one embodiment of the present invention, the user authentication server 200 may further include an encoding unit 240, an encoding unit 240 may encode the second challenge value (C ₁₎ using a standard encryption function . At this time, the transmitting unit 220 may transmit the encoded challenge value to the user authentication server 200. [ According to an embodiment of the present invention, the secret key used for encoding may be the first response value (R ₀ ) stored in the server 200 or received from the OTP generator 100.

In addition, the encoding unit 240 may convert the challenge value (C ₀ ) using a hash function to check the error of the message. The hash function may be a HMAC-based hash function, for example, and the response value R ₀ may be a secret key. The challenge value converted by the encoding unit 240 into the hash function includes a second challenge value C ₁ or a second challenge value C ₁ encoded in the encoding unit 240.

The present invention may further include a decoding unit 250. The decoded value is an encoded first response value R ₀ or a second response value R ₁ received from the OTP generator 100. According to an embodiment of the present invention, the secret key necessary for decoding may be the first response value (R ₀ ) stored in the server 200 or received from the OTP generator 100. The decoded second response value R ₁ is used as a secret key in the next encoding or decoding.

4 illustrates a protocol between an OTP generator and a user authentication server. Hereinafter, it will be described according to the flow of the overall system.

First, the user inputs transaction information to the user terminal (S610).

When transaction information is input to the user terminal, the user terminal transmits an authentication request message (Hello) to the user's OTP generator and the user authentication server (S620).

Then, the user authentication server may also send to the OTP generator of the user second challenge value (C ₁₎ to be used for, but the next time sending a challenge value (C ₀₎ to the OTP generator (S630).

At this time, the user authentication server can encode the second challenge value (C ₁ ) using the standard cryptographic function, and can transmit the encoded challenge value to the external server. The cryptographic functions include, for example, cryptographic algorithms such as HMAC-SHA1, SEED, and the like. At this time, the secret key may be the first response value (R ₀ ) corresponding to the first challenge value (C ₀ ).

In addition, the user authentication server may apply the hash function to the challenge value (C ₀ ) to check the error of the message, and may transmit the application result value to the user authentication server.

However, the challenge value converted into the hash function includes the second challenge value (C ₁ ) or the encoded second challenge value (C ₁ ). At this time, the secret key may be the first response value (R ₀ ) corresponding to the first challenge value (C ₀ ).

Then, the PUF module generates a response value (R ₀ ) corresponding to the challenge value (C ₀ ), and generates a second response value (R ₁ ) when the receiving section receives the second challenge value (C ₁ )

Then, the user authentication server decoding in a second challenge value (C ₁₎ for user authentication when receiving from the server an encoded second challenge value (C ₁₎ of the original second challenge value (C ₁₎ encoded by the server (S650 ). In this case, according to an embodiment of the present invention, the secret key used for decoding may be the first response value (R ₀ ) obtained from the PUF module. Because of the nature of the PUF module, which can not be physically replicated, only the OTP generator and the user authentication server can share the secret key, so the first response value (R ₀ ) is used as the secret key.

Then, OTP generator sends a second challenge response value from the second value (C ₁₎ when the (R ₁₎ to create a second response value (R ₁₎ to the user authentication server (S660). The response value in the user authentication server is updated so that it is possible to determine whether or not the OTP password is matched without accumulating an excessive CRP table. According to an embodiment of the present invention, the OTP generator may transmit the first response value (R ₀ ) to the user authentication server. This is because the OTP password generated by the user authentication server using the first response value (R ₀ ) It is to judge whether the OTP password inputted from the user coincide with each other.

Also, according to an embodiment of the present invention, the OTP generator may convert the response value (R ₀ ) using a hash function to check the error of the message, and transmit the result of the conversion to the user authentication server. The hash function may be a HMAC-based hash function, for example, and the response value R ₀ may be a secret key. At this time, since the OTP generator generates the corresponding response value (R ₀ ) using the PUF each time the challenge value (C ₀ ) is received from the server, the attacker can not obtain the response value (R ₀ ) which is the secret key.

However, the response value to be converted into the hash function includes the second response value R ₁ or an encoded response value to be described below.

According to an embodiment of the present invention, the OTP generator may encode a response value (R ₀ ) or a second response value (R ₁₎ using a standard cryptographic function and transmit the encoded response value to the user authentication server. The encoded response value can be directly transmitted to the user authentication server or converted to a hash function and transmitted to the user authentication server.

Then, the OTP generator generates an OTP password (S670) and transmits it to the user. At this time, information used to generate the password OTP may further include one including a time alignment information, and a response value (R ₀₎ private key, and transaction information. Also, the OTP password may be transmitted to the user through a separate output means.

Then, if the user inputs the OTP password to the user terminal using the input means, the user authentication server receives the OTP password (S680) and checks whether the OTP password matches the OTP password generated by the user authentication server (S690) The next challenge value (C ₁ ) _, and the response value (R ₁ ). Otherwise, the OTP authentication fails and is not updated. The updated response value R ₁ may be received from the OTP generator or may be generated by the user authentication server by its own PUF circuit.

Then, according to an embodiment of the present invention, the user authentication server transmits the next C ₁ to the OTP generator in response to the authentication completion ACK message (S700). At this time, it is possible to further transmit R ₁ . This allows the OTP generator to continuously generate a random OTP.

As described above, when using the OTP generator, the user authentication server or the password generation method of the present invention, the attacker can not recover any information because the desired information is encoded and protected using the response value of the PUF as the secret key. Therefore, the present invention is safe from eavesdropping attacks.

Also, the present invention verifies whether the OTP password is matched before updating the CRP information. If the verification is completed, the corresponding CRP is updated. Otherwise, the OTP authentication is not performed because the OTP authentication fails. Therefore, the present invention is safe from a message block attack.

Also, when the OTP generator, the user authentication server or the password generation method of the present invention is used, the Replay attack can be disabled because the OTP password is basically a one-time password. The CRP information exchanged between the OTP generator and the financial company server is updated every time, so the Replay attack becomes meaningless. That is, the CRP information is used only once and is not used next time. Therefore, the present invention is safe from Replay attack.

Also, the CRP that the present invention sends and receives for authentication is encoded and protected as information shared only by the OTP generator and the financial company server. If the CRP or OTP secrets do not match, the authentication fails. Since the present invention verifies the integrity of authentication messages by adding an HMAC-based hash value to the checksum, the present invention is safe from spoofing attacks.

Further, the present invention is not required to store the response value in the memory due to the characteristics of the PUF. Since the OTP generator generates the corresponding response value using the PUF whenever the challenge value is received from the server, the attacker can not obtain the response value which is the secret key.

Also, the OTP generator of the present invention adds a PUF to an existing OTP generator, and it is impossible to physically replicate the OTP generator due to the characteristics of the PUF. Therefore, replication attacks are impossible.

In conclusion, the present invention provides a more secure and more robust authentication method than the conventional OTP based financial transaction system.

1 refers to a hardware component such as software or an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit), and performs predetermined roles .

However, 'components' are not meant to be limited to software or hardware, and each component may be configured to reside on an addressable storage medium and configured to play one or more processors.

Thus, by way of example, an element may comprise components and processes such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, Microcode, circuitry, data, databases, data structures, tables, arrays, and variables, as will be appreciated by those skilled in the art.

The components and functions provided within those components may be combined into a smaller number of components or further separated into additional components.

One embodiment of the present invention may also be embodied in the form of a recording medium including instructions executable by a computer, such as program modules, being executed by a computer. Computer readable media can be any available media that can be accessed by a computer and includes both volatile and nonvolatile media, removable and non-removable media. In addition, the computer-readable medium may include both computer storage media and communication media. Computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Communication media typically includes any information delivery media, including computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave, or other transport mechanism.

The OTP-based authentication device and method according to the present invention can be implemented as computer-readable codes on a computer-readable recording medium. The computer-readable recording medium includes all kinds of recording media storing data that can be decoded by a computer system. For example, there may be a ROM (Read Only Memory), a RAM (Random Access Memory), a magnetic tape, a magnetic disk, a flash memory, an optical data storage device and the like. In addition, the computer-readable recording medium may be distributed and executed in a computer system connected to a computer network, and may be stored and executed as a code readable in a distributed manner.

While the present invention has been described with reference to particular embodiments, some or all of those elements or acts may be implemented using a computer system having a general purpose hardware architecture.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

100: OTP generator
110:
115: decoding unit
120: PUF module
130: OTP password generation unit
140:
150: encoding section

Claims (14)

An OTP (One Time Password) generator,
A receiving unit for receiving a challenge value (C ₀ ) from an external server;
A Physically Unclonable Fuction (PUF) module for generating a response value (R ₀ ) corresponding to the challenge value (C ₀ ); And
Time synchronization information, and the response value (R ₀ )
The receiver, the first challenge value (C ₀₎ OTP generator for receiving a second challenge value (C ₁₎ are encoded by the use of the response value (R ₀₎ at the time of receiving from the external server with the.
The method according to claim 1,
The OTP generator includes:
And a decoding unit for decoding a second challenge value (C ₁ ) encoded using the response value (R ₀ ).
3. The method of claim 2,
The PUF module includes:
Generates a second response value (R ₁ ) corresponding to the second challenge value (C ₁ )
The OTP generator includes:
And a transmitter for transmitting the second response value (R ₁ ) to the external server.
Claim 4 has been abandoned due to the setting registration fee. The method of claim 3,
And an encoding unit encoding the first response value (R ₀ ) or the second response value (R ₁ ) using the first response value (R ₀ )
The transmitter may further comprise:
And transmits the encoded first (R ₀ ) or second encoded response value (R ₁ ) to the external server.
Claim 5 has been abandoned due to the setting registration fee. 5. The method of claim 4,
The encoding unit may include:
The first response value R ₀ , the second response value R ₁ , the encoded first response value R ₀ using a hash function with the first response value R ₀ as a secret key, Or an encoded second response value (R ₁ ).
The method according to claim 1,
The receiver may further comprise:
Wherein the external server receives an ACK message indicating that the password received from the user is identical,
The ACK message includes a second challenge value (C ₁ ) and a second response value (R ₁ ) to be used next.
A server for authenticating a user in a financial transaction system,
A transmitter for transmitting a challenge value (C ₀ ) to an OTP generator including a PUF module;
A password generating unit for generating an OTP password using time synchronization information and a response value (R ₀ ) corresponding to the challenge value (C ₀ ); And
And an authentication unit for determining whether the OTP password inputted by the user matches the OTP password generated by the password generating unit
The response value (R ₀ ) has been stored in the server,
The OTP password input by the user,
Wherein the OTP password generated by the OTP generator using time synchronization information and the response value (R ₀ ) is input by the user.
8. The method of claim 7,
Further comprising an encoding unit for encoding a second challenge value (C ₁ ) to be used next using the first response value (R ₀ )
The transmitter may further comprise:
And transmits the first challenge value (C ₀ ) and the encoded second challenge value (C ₁ ).
9. The method of claim 8,
The second response value (R _1), the first response value corresponding to from the OTP generator to the first challenge value (C ₀₎ the first response value corresponding to the (R _0), the second challenge value (C ₁₎ (R ₀₎ Further comprising a receiver for receiving a first response value (R ₀ ) or a second response value (R ₁ ) encoded using the first response value (R ₀ ).
Claim 10 has been abandoned due to the setting registration fee. 10. The method of claim 9,
And a decoder for decoding the encoded first response value (R ₀ ) or the second response value (R ₁ ) using a first response value (R ₀ ).
8. The method of claim 7,
The transmitter may further comprise:
Transmits an ACK message indicating whether or not the OTP password input by the user matches the OTP password generated by the password generator,
The ACK message includes a second challenge value (C ₁ ) and a second response value (R ₁ ) to be used next.
10. The method according to claim 8 or 9,
The encoding unit may include:
The first response value R ₀ , the second response value R ₁ , the encoded first response value R ₀ , or the first response value R ₀ using a hash function with the response value R ₀ as a secret key, A user authentication server that transforms an encoded second response value (R ₁ ).
In a method for an OTP generator to generate a password,
Receiving a challenge value (C ₀ ) from an external server;
Generating a response value (R ₀ ) corresponding to the challenge value (C ₀ ) using the PUF module;
And generating a password using the time synchronization information and the response value (R ₀ )
The step of receiving the challenge value (C ₀ )
And receiving a second challenge value (C ₁ ) encoded from the external server together with the response value (R ₀ ) upon receiving the first challenge value (C ₀ ).
14. The method of claim 13,
The receiving step
And decoding the encoded second challenge value (C ₁ ) using a first response value (R ₀ ) corresponding to the first challenge value (C ₀ )
The generating step
Generating a first response value (R ₀ ) corresponding to the first challenge value (C ₀ ) using the PUF module and generating a second response value (R ₁ ) corresponding to the second challenge value (C ₁ ) and,
The password generation method includes:
Encoding the second response value (R ₁ ) and transmitting the second response value (R ₁ ) to the external server, wherein the first response value (R ₀ ) corresponding to the first challenge value (C ₀ ) is encoded using the first response value (R ₀ ).

Images