KR101210411B1 - Transaction Protection System and Method using Connection of Certificate and OTP Generated by Keystream - Google Patents

Abstract

The present invention is to solve the problem of the transaction protection system using only the existing public certificate or only OTP, Internet access module 11, the electronic signature module 12 including the public certificate, the first OTP module 13, SP server 20 and the digital signature authentication module 31, the second OTP module 32, the transaction verification module 33, and the OTP keyDB that provide the user terminal 10 and the service including the transaction encryption module 14 Including a certification authority server 30 comprising a 34, the terminal 10, SP server 20, the certification authority server 30 is connected to the network, the process of decrypting the private key in the public certificate The data extracted from is used for OTP generation, and the certification authority confirms the validity of the OTP and adds confidentiality in the certification process. Problem and OTP only Addresses vulnerabilities to phishing and man-in-the-middle attacks when used, and, unlike using only certified certificates, OTP without installing additional programs to encrypt transmitted data. Provides a transaction protection method and system using an OTP generated by a public certificate and a key sequence generator that overcomes the compatibility problem according to the terminal by encrypting using.

Description

Transaction Protection System and Method using Connection of Certificate and OTP Generated by Keystream}

The present invention relates to a transaction protection system and method using an OTP generated by a public certificate and a key sequence generator, using data extracted in the process of decrypting a private key from a public certificate for pseudo random number and OTP generation, and generating a pseudo random number. The present invention relates to a transaction protection system and method that encrypts a transaction by using a certificate and adds confidentiality in the certification process of the certificate by verifying the validity of the OTP by the certification authority.

With the development of information and communication technology, much of daily work is done through the Internet. When a malicious user accesses the Internet, an open network, for the purpose of eavesdropping, tampering, intrusion, etc., user authentication is essential for system security online. There are various technologies for such authentication method from ID / Password method to biotechnology authentication. These methods are used according to the security level step by step.

 The accredited certificate used in conjunction with the e-Signature Act of 1999 was distributed to general users as it was mandatory for electronic financial transactions, especially in the financial sector in 2003. As of May 2010, the number of issued certificates is 23 million, which is used by more than 90% of the economically active population. The field of use is also widely used throughout the society, such as Internet banking, securities trading, government complaints, procurement and military administration.

 As the public certificate is widely used in our daily lives, problems related to the public certificate have been raised. Representative examples are safety problems regarding the effectiveness of digital signatures due to the lack of web compatibility and the leakage of private keys. The recent controversy over the mandatory use of accredited certificates in electronic banking transactions is due to the emergence of various wireless terminals, such as smartphones, as a starting point for compatibility issues that are difficult to apply to the accredited certification services used in existing PC environments. However, controversy is growing with the issue of technological superiority with other certification means and deregulation of SMEs.

 Also, in recent years, one-time password (OTP), security card, and hardware security module (HSM) have been used around financial certificates and electronic commerce. An accredited certificate is a means of identity verification and non-repudiation, which means that if a transaction is digitally signed with the private key of the accredited certificate, the user cannot later deny the transaction. Therefore, the protection of the private key of the certificate is urgently needed. So it encrypts with the password you specify and stores it in the private key file. In addition, it also installs keyboard security programs and other security programs. This has a problem that depends on each type of smartphone or PC and the operating system or web browser. As a result, by holding several certificates, unnecessary inconvenience in terms of management and resources, as well as user inconvenience.

In the case of OTP, when a user requires authentication, a password is generated so that a different password is generated and reused each time. It is safe from the user's lost password or attacker's eavesdropping attacks. In addition, OTP is characterized by anonymity, portability, and scalability, and has strong authentication effects when used with SSL / TLS (Secure Socket Layer / Transport Layer Security). However, it provides confidentiality, integrity, and server authentication, but it does not provide nonrepudiation, and it is used for phishing attacks and man-in-the-middle attacks during the time that the value of OTP is maintained before the regeneration. It shows a vulnerability.

The present invention is to solve the problem of the transaction protection system using only the existing public certificate or only OTP, using the data extracted in the process of decrypting the private key in the public certificate for OTP generation, the validity of the OTP in the certification authority By verifying whether or not to add confidentiality in the authentication process of the certificate, safety issues regarding the validity of digital signatures due to the leakage of private keys when only the certificate service is used, phishing attacks and MITM (when using only OTP) It solves vulnerabilities in Man-in-the-Middle Attack and overcomes compatibility problems by handset by encrypting using OTP without installing additional program to encrypt transmitted data, unlike when using only public certificate. Provides a transaction protection method and system using OTP generated by a public certificate and a key sequence generator.

Transaction protection system using the OTP generated by the public certificate and key sequence generator of the present invention for solving the above problems,
A user terminal 10 including an internet access module 11, an electronic signature module 12 including an authorized certificate, a first OTP module 13, and a transaction encryption module 14; and
SP server 20 for providing a service; and
It includes; the digital signing authentication module 31, the second OTP module 32, the transaction verification module 33, the certificate authority server 30 including the OTP keyDB 34;
The terminal 10, SP server 20, the certification authority server 30 is connected by a network,
The Internet access module 11 generates a first transaction TR_1 when a user requests a service from the SP server 20,
The electronic signature module 12 receives a password from a user and encrypts the first transaction TR_1 with a built-in hash function when the electronic signature is required when the first transaction TR_1 is transmitted to the SP server 20. After generating one h (TR_1) and the electronic signature on the h (TR_1) to generate an electronic signature file (SignU),
The first OTP module 13 receives a DIV (Derived Initial Vector) generated during the digital signature process, removes an IV (Initial Vector), generates an OTP key, inputs the built-in key sequence generator, and inputs the first OTP and the first doctor. Generate random numbers,
The transaction encryption module 14 performs an XOR operation on the first random number and the first transaction TR_1 to generate an encrypted TRansaction (ETR).
The Internet access module 11 transmits the first OTP, ETR, and electronically signed file to the SP server 20,
The SP server 20 transmits the first OTP, ETR, and digitally signed file to a CA (Certificate Authority),
The CA transmits the digitally signed file to the digital signature authentication module 31, and transmits the first OTP and the first ETR to the transaction verification module 33.
The digital signature authentication module 31 encrypts the h (TR_1) by encrypting the first transaction TR_1 with the built-in hash function using the same public key embedded in the digital signature module 12. From extracted files,
The second OTP module 32 searches for the OTP key of the user in the OTP keyDB 34 in which the OTP key distributed for each user is stored, inputs it to the same key sequence generator as the first OTP module 13, and enters the second OTP and the second OTP key. Generate a second random number,

The transaction verification module 33 generates a second transaction TR_2 by performing an XOR operation on the ETR and the second random number when the received first OTP and the second OTP are the same, and generates the second transaction TR_2 by the electronic signature. By generating the h (TR_2) with the same hash function as the module 12, it is characterized in that to transmit the authentication information to the SP server 20 when h (TR_2) is equal to h (TR_1).

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In the transaction protection system using the OTP generated by the public certificate and key sequence generator of the present invention for solving the above problems,

The certification authority server 30 further includes a PINDB 35 in which a PIN distributed for each user is stored.

When the OTP key is different from the key sequence generator and the use bit,

The first OTP module 13 and the second OTP module 32,

When the OTP key is transmitted to the key sequence generator, the OBIT key is transformed into an use bit of the key sequence generator using an OTP key preprocessing process that receives the PIN and the OTP key as variables. It is done.

In the transaction protection system using the OTP generated by the public certificate and key sequence generator of the present invention for solving the above problems,

When the input values of the OTP key and the key sequence generator are represented in binary form,

의 값을 가지되,The OTP key transformed into the OTP key preprocessing process is

Has the value of

N is a value obtained by dividing the use bit of the key sequence generator by the use bit of the original OTP key before modification;

는 Each in the OTP key

The

의 식을 만족하되,

Satisfies the

이며, j=0일 때 상기 식의

의 값으로는 상기 PIN을 입력하는 것을 특징으로 한다.
The OTP key before deformation

And when j = 0

The value of is characterized in that the input of the PIN.

Transaction protection method using the OTP generated by the public certificate and key sequence generator of the present invention for solving the above problems,
Generating, by the Internet access module 11, a first transaction TR_1 when the user requests a service from the SP server 20 (S10);
When the electronic signature module 12 transmits the first transaction TR_1 to the SP server 20, if the electronic signature is required, the electronic signature module 12 receives a password from a user and encrypts the first transaction TR_1 with a built-in hash function. Generating an electronic signature (SignU) by generating an h (TR_1) and then electronically signing the h (TR_1) (S20);
The first OTP module 13 receives a DIV (Derived Initial Vector) generated during the digital signature process, removes an IV (Initial Vector), generates an OTP key, inputs it into an embedded key sequence generator, and enters the first OTP and the first doctor. Generating a random number (S30);
Generating, by the transaction encryption module (14), an XTR operation on the first random number and the first transaction (TR_1) to generate an encrypted TRansaction (ETR);
The Internet access module 11 transmits the first OTP, ETR, and electronically signed file to the SP server 20, and the SP server 20 sends the first OTP, ETR, and electronically signed file to a CA (Certificate Authority). Transmitting the digitally signed file to the digital signature authentication module (31), and transmitting the first OTP and the first ETR to the transaction verification module (33);
The digital signature of the h (TR_1) by encrypting the first transaction (TR_1) with a built-in hash function using the same public key embedded in the digital signature module 12 is the electronic signature authentication module 31 Extracting from the extracted file (S60);
The second OTP module 32 searches for the OTP key of the user in the OTP keyDB 34 in which the OTP key distributed for each user is stored and inputs it to the same key sequence generator as the built-in first OTP module 13. Generating a second random number (S70);

When the first OTP and the second OTP received by the transaction verification module 33 are the same, the second transaction TR_2 is generated by performing an XOR operation on the ETR and the second random number, and the second signature TR_2 is the electronic signature. Generating an H (TR_2) with the same hash function as that built into the module 12 and transferring authentication information to the SP server 20 when h (TR_2) is equal to h (TR_1) (S80); It is characterized by including.

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In the transaction protection method using the OTP generated by the public certificate and key sequence generator of the present invention for solving the above problems,

Generating the first OTP and the first random number and generating the second OTP and the second random number may include:

When the OTP key is different from the key sequence generator and the use bit, when the first OTP module 13 and the second OTP module 32 transmit the OTP key to the key sequence generator, the use bit of the OTP key is read. Using the OTP key preprocessing process that receives the PIN and the OTP key as variables, it is transformed into the use bit of the key sequence generator and transferred.

When the input values of the OTP key and the key sequence generator are represented in binary form,

의 값을 가지되,The OTP key transformed into the OTP key preprocessing process is

Has the value of

N is a value obtained by dividing the use bit of the key sequence generator by the use bit of the original OTP key before modification;

는 Each in the OTP key

The

의 식을 만족하되,

Satisfies the

이며, j=0일 때 상기 식의

의 값으로는 상기 PIN을 입력하는 것을 특징으로 한다.
The OTP key before deformation

And when j = 0

The value of is characterized in that the input of the PIN.

Transaction protection system and method using the OTP generated by the public certificate and key sequence generator of the present invention is a safety problem regarding the effectiveness of the digital signature by the private key leakage when using only the public authentication service and phishing when using only OTP ( By linking the digital signature module and the OTP module with vulnerabilities to phishing attack and man-in-the-middle attack attack, one of the leaked or hacked, and the malicious authority tries to authenticate the service. It can be resolved by rejecting it, and it can be used regardless of the type of terminal by overcoming compatibility problems caused by the use of various wireless terminals such as smart phone dissemination. In terms of resources, unnecessary consumption can be reduced.

1 is a diagram illustrating a transaction protection system using an OTP generated by a public certificate and a key sequence generator according to the present invention.
Figure 2 illustrates a transaction protection method using OTP generated by the public certificate and key sequence generator in the present invention.
3 is a detailed flowchart of a transaction protection method using OTP generated by the public certificate and key sequence generator of FIG. 2.
4 is a diagram illustrating a method of extracting an OTP key applied to the present invention.

The present invention uses the data extracted in the process of decrypting the private key in the public certificate for OTP generation, by checking the validity of the OTP in the certification authority to add confidentiality in the process of authentication of the public certificate, thereby utilizing only the existing public certificate or The problem of the transaction protection system using only OTP is solved. The configuration and implementation method are as follows.

1 is a diagram illustrating a transaction protection system using an OTP generated by a public certificate and a key sequence generator according to the present invention, and FIG. 2 illustrates a transaction protection method using an OTP generated by a public certificate and a key sequence generator. 3 is a detailed flowchart of a transaction protection method using an OTP generated by the public certificate and key sequence generator of FIG. 2, and FIG. 4 is a diagram illustrating a method of extracting an OTP key applied to the present invention. .

The transaction protection system using the OTP generated by the public certificate and the key sequence generator of the present invention, as shown in Figure 1, the Internet connection module 11, the electronic signature module 12 including the public certificate, the first OTP module 13 SP server 20 and the digital signature authentication module 31, the second OTP module 32, the transaction verification module 33, which provides the user terminal 10 and the service including the transaction encryption module 14, Including a certification authority server 30 including an OTP keyDB 34, the terminal 10, SP server 20, the certification authority server 30 is connected to the network.

The Internet access module 11 generates a first transaction TR_1 when a user requests a service from the SP server 20.

The electronic signature module 12 receives a password from a user and encrypts the first transaction TR_1 with a built-in hash function when the electronic signature is required when the first transaction TR_1 is transmitted to the SP server 20. After generating one h (TR_1) and then digitally signing the h (TR_1), an electronically signed file (SignU) is generated.

At this time, the digital signature module 12 extracts the OTP key in the digital signature process as shown in FIG. The public certificate consists of a signCert.der file and a signPri.key file. The private key The key is stored encrypted in the signPri.key file. When the user enters the public certificate password, the encrypted private key is extracted, and the salt and iteration count are extracted from the encrypted private key. Salt is generated in the form of a random number each time a certificate is issued, which prevents an unspecified number of dictionary attacks. And the iteration count contains a hash function for generating the secret key. Derived key, which is an extraction key, is extracted by using the authentication certificate password entered by the user and salt and iteration count. The first 16 bytes of the derived key are used as the encryption key for decryption of the private key, and the remaining 4 bytes are extended to 20 bytes through the SHA-1 function. The first 16 bytes of the DIV are extracted from the initialization vector IV. This process is the same as the existing certificate method. The part to be used in the present invention is to extract the IV in this process and use the remaining 4 bytes as the OTP key.

The first OTP module 13 receives the DIV generated during the digital signature process, removes the IV, generates an OTP key, and inputs the built-in key sequence generator to generate the first OTP and the first random number.

The transaction encryption module 14 performs an XOR operation on the first random number and the first transaction TR_1 to generate an ETR.

The Internet access module 11 transmits the first OTP, ETR, and electronically signed file to the SP server 20, and the SP server 20 transmits the first OTP, ETR, and electronically signed file to the CA. The CA transmits the digitally signed file to the digital signature authentication module 31 and transmits the first OTP and the first ETR to the transaction verification module 33.

The digital signature authentication module 31 extracts h (TR_1) from the digitally signed file by using the same public key as that embedded in the digital signature module 12.

The second OTP module 32 searches for the OTP key of the user in the OTP keyDB 34 in which the OTP key distributed for each user is stored, inputs it to the same key sequence generator as the first OTP module 13, and enters the second OTP and the second OTP key. Generate a second random number.

The transaction verification module 33 generates a second transaction TR_2 by performing an XOR operation on the ETR and the second random number when the received first OTP and the second OTP are the same, and generates the second transaction TR_2 by the electronic. It generates the h (TR_2) with the same hash function as the one embedded in the signature module 12, and transmits the authentication information to the SP server 20 when h (TR_2) is equal to h (TR_1).

The certification authority server 30 may further include a PINDB 35 in which a PIN distributed for each user is stored.

The first OTP module 13 and the second OTP module 32 transmit the OTP key to the key sequence generator when the OTP key is different from the key sequence generator, and indicates the use bit of the OTP key. Using the OTP key preprocessing process that receives the PIN and the OTP key as variables, it is transformed into the use bit of the key sequence generator and transferred.

의 값을 가지되, 상기 n은 상기 키수열발생기의 사용 bit를 원래의 변형전 OTP key의 사용 bit로 나눈 값이며, 상기 OTP key에서의 각

는

의 식을 만족하되, 상기 변형전 OTP key는

이며, 이때(j=0일 때), 상기 식의

의 값으로는 상기 PIN을 입력하는 것을 특징으로 한다.
When the input values of the OTP key and the key sequence generator are represented in binary form, the OTP key transformed into the OTP key preprocessing process is

N is a value obtained by dividing the use bit of the key sequence generator by the use bit of the original OTP key before modification, and

The

Satisfies the equation, but the OTP key before deformation

Where (when j = 0),

The value of is characterized in that the input of the PIN.

The OTP key extracted in the above process is 32 bits, and when it is input to the key sequence generator, it is necessary to set a flexible OTP key because the use bits are different for each algorithm of the key sequence generator.

는 상기 식

에 따라, OTP key 값을 좌측으로 1bit 이동하고 우측에는 “0”으로 설정한 뒤 비트 이동 전의 값과 XOR연산을 실시한다.For example, if the algorithm of the key sequence generator uses 128 bits, the OTP key should also be changed to 128 bits. The OTP key value obtained from the accredited certificate is 32 bits, so the value of n is 4 and each

Is the above formula

As a result, OTP key value is moved 1 bit to the left and “0” is set to the right and then the XOR operation is performed with the value before bit movement.

For example, the above process is described in more detail.

The transaction protection method using the OTP generated by the public certificate and the key sequence generator of the present invention, using the transaction protection system using the OTP generated by the public certificate and the key sequence generator, as shown in Figures 2 and 3 , The first transaction generation step S10, the SignU generation step S20, the first OTP / first random number generation step S30, the ETR generation step S40, the first OTP / ETR / SignU transmission step S50, and The first transaction extraction stage S60, the second OTP / second random number generation step S70, and the transaction verification step S80 are included.

The first transaction generating step (S10) is a step in which the Internet connection module 11 generates a first transaction TR_1 when the user requests a service from the SP server 20. When the user requests a service use to the SP server and logs in, the Internet access module 11 generates a first transaction TR_1 to be transmitted. For example, in the case of bank transfer, the contents of the first transaction TR_1 may be information such as a receiver, a receiving account, a transfer amount, and a time.

The SignU generation step (S20) When the electronic signature module 12 transmits the first transaction TR_1 to the SP server 20, the electronic signature module receives a password from a user and inputs the password into a public certificate to signPri. Decrypts the key file, extracts the DIV value in the process, generates h (TR_1) by encrypting the first transaction TR_1 with the built-in hash function, and digitally signs the h (TR_1) by digital signature. Create a signed file (SignU).

The first OTP / first random number generation step (S30) The first OTP module 13 receives the DIV generated during the digital signature process, removes the IV, generates an OTP key, and inputs the built-in key sequence generator to generate the first OTP and the first random number.

In the ETR generating step (S40) , the transaction encryption module 14 performs an XOR operation on the first random number and the first transaction TR_1 to generate an ETR, which is an encrypted transaction.

The first OTP / ETR / SignU transmission step (S50) The Internet access module 11 transmits the first OTP, ETR, and electronically signed file to the SP server 20, and the SP server 20 transmits the first OTP, ETR, and electronically signed file to the CA. The CA transmits the digitally signed file to the digital signature authentication module 31 and transmits the first OTP and the first ETR to the transaction verification module 33.

The first transaction extraction stage S60 extracts h (TR_1) from the digitally signed file using the same public key that the digital signature authentication module 31 is embedded in the digital signature module 12.

The second OTP / second random number generation step (S70) The second OTP module 32 searches for the OTP key of the user in the OTP keyDB 34 in which the OTP key distributed for each user is stored and is embedded in the first OTP module ( Input to the same key sequence generator as in 13) to generate the second OTP and the second random number.

In the transaction verification step S80, when the transaction verification module 33 is identical to the received first OTP and the second OTP, the transaction verification module 33 generates the second transaction TR_2 by performing an XOR operation on the ETR and the second random number. 2 transactions (TR_2) is generated as h (TR_2) with the same hash function as the built in the digital signature module 12, if the h (TR_2) is equal to h (TR_1) authentication information to the SP server 20 To pass.

The generating of the first OTP and the first random number and the generating of the second OTP and the second random number may include: when the OTP key is different from the key sequence generator, the first OTP module 13 and When the second OTP module 32 transmits the OTP key to the key sequence generator, the use bit of the key sequence generator using an OTP key preprocessing process that receives the use bit of the OTP key as the variable and the PIN and the OTP key. Transmit it to

Preferred embodiments of the present invention described above are disclosed to solve the technical problem, and those skilled in the art to which the present invention pertains will be capable of various modifications, changes, additions, etc. within the spirit and scope of the present invention. Such changes, modifications and the like should be considered to be within the scope of the following claims.

10 terminal 11 Internet access module
12: digital signature module 13: 1 OTP module
14: transaction encryption module 20: SP server
30: certification authority server 31: digital signature authentication module
32: second OTP module 33: transaction verification module
34: OTP keyDB 35: PINDB
S10: first transaction generation step S20: signU generation step
S30: first OTP / first random number generation step S40: ETR generation step
S50: first OTP / ETR / SignU transmission step S60: first transaction extraction step
S70: second OTP / second random number generation step S80: transaction verification step

Claims (5)

A user terminal 10 including an internet access module 11, an electronic signature module 12 including an authorized certificate, a first OTP module 13, and a transaction encryption module 14; and
SP server 20 for providing a service; and
It includes; the digital signing authentication module 31, the second OTP module 32, the transaction verification module 33, the certificate authority server 30 including the OTP keyDB 34;
The terminal 10, SP server 20, the certification authority server 30 is connected by a network,
The Internet access module 11 generates a first transaction TR_1 when a user requests a service from the SP server 20,
The electronic signature module 12 receives a password from a user and encrypts the first transaction TR_1 with a built-in hash function when the electronic signature is required when the first transaction TR_1 is transmitted to the SP server 20. After generating one h (TR_1) and the electronic signature on the h (TR_1) to generate an electronic signature file (SignU),
The first OTP module 13 receives a DIV (Derived Initial Vector) generated during the digital signature process, removes an IV (Initial Vector), generates an OTP key, inputs the built-in key sequence generator, and inputs the first OTP and the first doctor. Generate random numbers,
The transaction encryption module 14 performs an XOR operation on the first random number and the first transaction TR_1 to generate an encrypted TRansaction (ETR).
The Internet access module 11 transmits the first OTP, ETR, and electronically signed file to the SP server 20,
The SP server 20 transmits the first OTP, ETR, and digitally signed file to a CA (Certificate Authority),
The CA transmits the digitally signed file to the digital signature authentication module 31, and transmits the first OTP and the first ETR to the transaction verification module 33.
The digital signature authentication module 31 encrypts the h (TR_1) by encrypting the first transaction TR_1 with the built-in hash function using the same public key embedded in the digital signature module 12. From extracted files,
The second OTP module 32 searches for the OTP key of the user in the OTP keyDB 34 in which the OTP key distributed for each user is stored, inputs it to the same key sequence generator as the first OTP module 13, and enters the second OTP and the second OTP key. Generate a second random number,
The transaction verification module 33 generates a second transaction TR_2 by performing an XOR operation on the ETR and the second random number when the received first OTP and the second OTP are the same, and generates the second transaction TR_2 by the electronic signature. Certified certificate, characterized in that to generate the h (TR_2) with the same hash function as built in the module 12, if the h (TR_2) is equal to h (TR_1) to pass the authentication information to the SP server 20 And a transaction protection system using OTP generated by a key sequence generator.
The method of claim 1,
The certification authority server 30 further includes a PINDB 35 in which a PIN distributed for each user is stored.
When the OTP key is different from the key sequence generator and the use bit,
The first OTP module 13 and the second OTP module 32,
When the OTP key is transmitted to the key sequence generator, the OBIT key is transformed into an use bit of the key sequence generator using an OTP key preprocessing process that receives the PIN and the OTP key as variables. Transaction protection system using OTP generated by a certificate and key sequence generator.
The method of claim 2,
When the input values of the OTP key and the key sequence generator are represented in binary form,
The OTP key transformed into the OTP key preprocessing process is

Has the value of
N is a value obtained by dividing the use bit of the key sequence generator by the use bit of the original OTP key before modification;
Each in the OTP key

The

Satisfies the
The OTP key before deformation

And when j = 0

A transaction protection system using an OTP generated by a public certificate and a key sequence generator, characterized in that the input of the PIN.
A user terminal 10 including an internet access module 11, an electronic signature module 12 including an authorized certificate, a first OTP module 13, and a transaction encryption module 14; and
SP server 20 for providing a service; and
It includes; the digital signing authentication module 31, the second OTP module 32, the transaction verification module 33, the OTP keyDB 34, the PINDB 35, the certification authority server 30;
In the transaction protection method using a transaction protection system using the OTP generated by the terminal 10, the SP server 20, the certification authority server 30 is connected to the network by a public certificate and a key sequence generator,
Generating, by the Internet access module 11, a first transaction TR_1 when the user requests a service from the SP server 20 (S10);
When the electronic signature module 12 transmits the first transaction TR_1 to the SP server 20, if the electronic signature is required, the electronic signature module 12 receives a password from a user and encrypts the first transaction TR_1 with a built-in hash function. Generating an electronic signature (SignU) by generating an h (TR_1) and then electronically signing the h (TR_1) (S20);
The first OTP module 13 receives a DIV (Derived Initial Vector) generated during the digital signature process, removes an IV (Initial Vector), generates an OTP key, inputs it into an embedded key sequence generator, and enters the first OTP and the first doctor. Generating a random number (S30);
Generating, by the transaction encryption module (14), an XTR operation on the first random number and the first transaction (TR_1) to generate an encrypted TRansaction (ETR);
The Internet access module 11 transmits the first OTP, ETR, and electronically signed file to the SP server 20, and the SP server 20 sends the first OTP, ETR, and electronically signed file to a CA (Certificate Authority). Transmitting the digitally signed file to the digital signature authentication module (31), and transmitting the first OTP and the first ETR to the transaction verification module (33);
The digital signature of the h (TR_1) by encrypting the first transaction (TR_1) with a built-in hash function using the same public key embedded in the digital signature module 12 is the electronic signature authentication module 31 Extracting from the extracted file (S60);
The second OTP module 32 searches for the OTP key of the user in the OTP keyDB 34 in which the OTP key distributed for each user is stored and inputs it to the same key sequence generator as the built-in first OTP module 13. Generating a second random number (S70);
When the first OTP and the second OTP received by the transaction verification module 33 are the same, the second transaction TR_2 is generated by performing an XOR operation on the ETR and the second random number, and the second signature TR_2 is the electronic signature. Generating an H (TR_2) with the same hash function as that built into the module 12 and transferring authentication information to the SP server 20 when h (TR_2) is equal to h (TR_1) (S80); Transaction protection method using OTP generated by a public certificate and a key sequence generator comprising a.
5. The method of claim 4,
Generating the first OTP and the first random number and generating the second OTP and the second random number may include:
When the OTP key is different from the key sequence generator and the use bit, when the first OTP module 13 and the second OTP module 32 transmit the OTP key to the key sequence generator, the use bit of the OTP key is read. Using the OTP key preprocessing process that receives the PIN and the OTP key as variables, it is transformed into the use bit of the key sequence generator and transferred.
When the input values of the OTP key and the key sequence generator are represented in binary form,
The OTP key transformed into the OTP key preprocessing process is

Has the value of
N is a value obtained by dividing the use bit of the key sequence generator by the use bit of the original OTP key before modification;
Each in the OTP key

The

Satisfies the
The OTP key before deformation

And when j = 0

A transaction protection method using an OTP generated by a public certificate and a key sequence generator, characterized in that the input of the PIN.

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