KR100468154B1 - System and method for business of electronic finance bases of smart card - Google Patents

Abstract

The present invention is used for electronic banking transactions using bank tellers, cash dispensers, Internet banking, etc., the bank's ledger database along with account information, the secret key for generating a message authentication code (MAC) when opening an account of the bank. Each time there is a financial transaction, the cryptographic authentication code generator generates a cryptographic authentication code (MAC) using the stored cryptographic authentication code generation secret key and transaction record data as an operation factor. The present invention relates to a smart card-based electronic financial transaction system and method for storing information in a bankbook (eg IC card) in a relational manner so that the counterfeiting or tampering with an electronic bankbook is more clearly performed.

In the present invention as described above, even if an attacker illegally tamperes with the transaction record, a cryptographic authentication code (MAC) that matches the cryptographic authentication code (MAC) handled by the bank server cannot be generated. By validating the digital signature value calculated from the information, it is possible to prove an illegal cryptographic authentication code (MAC), and even if an attacker illegally changes the account information in the electronic account, the card number cannot be tampered with, thus greatly improving security. There is.

Description

Smart card based electronic financial transaction system and method thereof {System and method for business of electronic finance bases of smart card}

The present invention relates to an electronic financial transaction system and method for improving the security of an electronic financial transaction medium (hereinafter referred to as an electronic bank account) used for electronic financial transactions using a bank teller, an ATM, or an internet banking. In more detail, the secret key for generating a message authentication code (MAC) is stored in the ledger database of the bank together with the account information when the bank opens the account, and the stored password authentication code is generated whenever there is a financial transaction. After generating the cryptographic authentication code (MAC) in the predetermined cryptographic authentication code generator using the secret key and transaction record data as the operation factors, the electronic account account is stored in the electronic bank account (for example, smart card) along with the corresponding transaction record data. Smart card-based electronic financial transaction system and its method to more clearly collaborate with financial institutions when counterfeiting or tampering with It relates.

Currently, financial transaction systems provided by banks use a notebook-type bankbook as a tool for keeping records of customers' financial transactions.In order to provide convenience in use, a cash card composed of a magnetic stripe card is issued for automatic cash advance. ATMs allow cash withdrawals.

However, using a simple card reader and a computer, the MS card is not only easy to read recorded information but also easy to reproduce, and various financial accidents occur frequently.

To solve this problem, there is a movement to replace the MS card with an IC card (also called a "smart card") that is difficult to duplicate.

By using such an IC card, not only is it difficult to duplicate, but also replaces the function of a large and cumbersome account in the form of a conventional notebook, it can integrate bankbook and cash card functions and manage multiple accounts in one IC card. It is expected that electronic passbooks using IC cards will be activated.

However, simply storing the bank account, cash card account information, and transaction records on the IC card is more secure than the MS card, but it is possible for an attacker to tamper with the transaction record or record the account information on another IC card and use it illegally. This still exists.

The present invention has been made to solve the above problems, the object of which is to prevent data tampering of a financial transaction system using an electronic bank account (eg, IC card), and to easily identify an illegally copied electronic bank account. The present invention provides a smart card-based electronic financial transaction system and method thereof.

In order to achieve the object of the present invention, the bank server for transmitting and receiving data with the terminal through the network, the ledger database for storing the cryptographic authentication code (MAC) generated for each financial transaction to be associated with the corresponding transaction record data, A cryptographic authentication code generator that generates a cryptographic authentication code (MAC) using transaction record data and cryptographic authentication code generation secret keys generated during financial transactions under control, and a card recorder for reading or writing data from an electronic bank account. The terminal controls the card recorder to transmit the data in the electronic bankbook read from the card recorder to the bank server through the network, and to store the cryptographic authentication code (MAC) transmitted from the bank server in association with the corresponding account information along with the transaction record data. And electronic bankbook for storing transaction record data, cryptographic verification code (MAC), and account information. The smart card-based electronic banking system is configured to provide.

In order to achieve the object of the present invention, every time there is a financial transaction, using the transaction record data and the secret key for generating the encryption authentication code as an operation factor, after generating the encryption authentication code (MAC) in the encryption authentication code generator and the transaction record data The smart card-based electronic financial transaction method is provided by configuring to store each in ledger database and electronic bank account.

1 is a block diagram showing an electronic financial transaction system according to the present invention.

2 is a view for explaining the process of generating a secret key for generating a password authentication code and a password authentication code according to the present invention;

3 is a flowchart illustrating the operation of the electronic financial transaction system according to the present invention.

* Explanation of Signs of Major Parts of Drawings *

20: Bank Server 22: Ledger Database

24: password authentication code generator 26: password authentication code generator secret key generator

30: electronic bankbook 40: terminal

42: card recorder 50: network

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

1 is a block diagram showing an electronic financial transaction system according to the present invention. The bank server 20 has a ledger database 22, a cryptographic authentication code generator 24, and a cryptographic authentication code generation as shown in FIG. A secret key generator 26 is provided, and the ledger database 22 includes a customer's account information (eg, account number), a card number of the electronic bank account 30, and a secret key for generating a password authentication code that is differently provided for each account. It stores data such as financial transaction record data (e.g. withdrawal amount, deposit amount, balance, etc.), cryptographic authentication code (MAC).

Herein, the cryptographic authentication code (MAC) is generated every time in the cryptographic authentication code generator 24 by using the transaction record data and the secret key for generating the cryptographic authentication code as an operation factor every time there is a financial transaction, and in relation to the corresponding transaction record data. In addition to being stored in the ledger database 22, the same is also stored in the electronic bank account 30 of the account.

In addition, the transaction record data and the encryption authentication code (MAC) stored in the ledger database 22 may be configured to be extinguished when the specified period expires or to be stably stored for a long time by backing up to another storage medium, the electronic bank account 30 The transaction record data and the encryption authentication code (MAC) contained in the) may be configured to destroy the data in the order of the oldest when the recording date exceeds the limited memory capacity at the time of recording.

In addition, the secret key for generating the password authentication code is identifiably assigned to one account information one by one, stored in association with the account information in the ledger database 22 of the bank server 20, the terminal through the network ( Transmission to 40 is not allowed and security is maintained.

In addition, the secret key for password authentication code generation uses a secret key generator for password authentication code 26 to generate a predetermined digital signature (the customer information of the electronic bank account 30 and the value of the bank's digital signature key as an operation factor. It may be composed of the electronic signature value of the bank made through 25), and may be used after calculating the electronic signature value to another value through the secret key derivative 27.

In addition, the encryption authentication code generator 24 is provided in the bank server 20, and under the control of the bank server 20, the encryption is performed using the transaction record data generated during the financial transaction and the secret key for generating the encryption authentication code as operators. Generate a verification code (MAC).

At this time, the password authentication code generator 24 generates cryptographically secure hash function encryption process (SHA-1, MD5, HAS-160, etc.) and symmetric key encryption generation process (DES, AES) in the process of generating the encryption authentication code (MAC). , SEED, etc.), digital signature encryption process (RSA, DSA, KCDSA, etc.) can be configured to undergo any one of the encryption process.

The cryptographic authentication code generation secret key generator 26 uses the customer information of the electronic bank account 30 and the electronic signature key value of the bank as operation factors, and the electronic signature of the bank made through the predetermined digital signature machine 25. The value or its digital signature value is again generated through the secret key inducer 27 to generate a secret key for encryption authentication code generation. In addition, the secret key for generating the password authentication code once generated and stored in the ledger database 22, or generated and used only when necessary to further improve security, and then destroyed without storing in the ledger database 22. Can be.

On the other hand, the terminal 40 transmits and receives data to and from the bank server 20 through the network 50, the computer is provided in the bank used by the bank clerks used by the cashier side computer, the home bank or the Internet used through the network 50 It may be configured from a personal computer in the workplace, a personal digital assistant (PDA) or a cash dispenser carried by a customer.

In addition, the terminal 40 is provided with an external or built-in card recorder 42 capable of reading or writing data from the electronic bankbook 30 to read the data in the electronic bankbook 30 and through the network 50 through the bank server. (20), and the cryptographic authentication code (MAC) transmitted from the bank server 20 is stored in the electronic bank account 30 to be associated with the corresponding account information with the transaction record data.

In addition, the electronic bankbook 30, which is held and managed by the customer, is connected to the card recorder 42 to transmit / receive data (also referred to as a "smart card") and the card recorder 42 in close proximity. An RF card for transmitting and receiving data wirelessly, a USB storage device or a flash storage device for transmitting and receiving data by connecting to the IEE1394 port may be configured.

In addition, the electronic bank 30 has a flash memory which does not lose recorded data even when the power supply is stopped. The control unit 34 such as at least one microprocessor (CPU) and a mask-ROM type program are provided therein. The memory 32 may be embedded to output only the results of data access or comparison.

At this time, the electronic bank account 30 stores the same account information, card number, transaction record data, password authentication code (MAC) and the like as the data stored in the ledger database 22 of the bank server 20, between the account information By assigning a separate storage area it is possible to integrate and manage a plurality of account information in one electronic bank account (30).

In this case, the transaction record data and the encryption authentication code (MAC) are stored in a storage area allocated to the corresponding account information.

2 is a view for explaining a process of generating a secret authentication code and secret code for generating a password authentication code according to the present invention, the process of generating a secret key for generating a password authentication code as shown therein The electronic signature device 25 provided in the secret key generator 26 for password authentication code generation using customer information consisting of data such as account information and card number of the electronic bank account 30 and a secret key for electronic signature of the bank as an operation factor. The digital signature value generated by arithmetic processing is substituted into the secret key for encryption authentication code generation as it is, or the newly derived value is passed through the secret key derivator 27 and the secret value for password authentication code generation is used. You can also apply to keys.

The secret key for generating the password authentication code generated by the above process is given differently for each account, and is used as a factor for generating a password authentication code (MAC) generated every time there is a financial transaction. That is, the cryptographic authentication code (MAC) is generated through the encryption operation process in the cryptographic authentication code generator 24 by using the transaction record data and the cryptographic authentication code generation secret key in the bank server 20 as an operation factor every time there is a financial transaction. Done.

On the other hand, Figure 3 is a flowchart for explaining the operation of the electronic financial transaction system according to the present invention, as shown in the ledger database 22 of the bank server 20 and the electronic bank account 30 of the customer The account information and the card number are stored respectively, and each time a financial transaction request is made, the electronic bank account 30 and the account information stored in the ledger database 22 are compared with each other to compare whether the card number is identical to the electronic bank account ( 30) it was configured to screen. (Step S10, Step S12, Step S14, Step S16, Step S18, Step S20 in Fig. 3)

In addition, the comparison between the account information and the card number stored in the electronic bank account 30 and the ledger database 22, first, by reading the account information stored in the electronic bank account 30 through the card recorder 42 of the terminal 40, the network ( 50 to the bank server 20, the bank server 20 reads the card number corresponding to the received account information from the ledger database 22 to the card recorder via the network 50 and the terminal 40 The electronic bankbook 30 may be transmitted to the electronic bankbook 30 through 42, and the electronic bankbook 30 may be configured to output only the correspondence between the received card number and the card number stored in the terminal 40 to the terminal 40.

In addition, the cryptographic authentication code generation secret key is stored in the ledger database 22 of the bank server 20, and each time there is a financial transaction, the transaction record data and the password authentication code generation secret key are used as the operation factors. After generating the encryption authentication code (MAC) in the authentication code generator 24 is stored in the ledger database 22 and the electronic bank 30 with the transaction record data, respectively. (Step S22, Step S24, Step S26, Step S28 in Fig. 3)

Hereinafter, the operation according to the present invention will be described in detail with reference to the accompanying drawings.

When a customer opens an account, each account is given a different secret key for generating a password, and the process of generating the secret key for generating a secret code is as shown in FIG. 2. The digital signature value of the bank created by the digital signature unit 25 in the cryptographic authentication code generation secret key generator 26 using the information (e.g., account information, card number) and the bank's digital signature key value as an operation factor. It can be applied to the secret key for encryption authentication code generation, and on the other hand, a value derived differently from the generated digital signature value through the secret key inducer 27 can be applied to the secret key for encryption authentication code generation.

The secret key for generating the password authentication code generated as described above is stored with the account information and the card number in the ledger database 22 of the bank server 20 as a factor for generating a password authentication code (MAC) whenever there is a financial transaction. Used. In addition, in order to further improve security, the secret key for cryptographic authentication code generation may be generated and used in real time every time there is a financial transaction, and then destroyed.

On the other hand, Figure 3 is a flow chart for explaining the operation of the electronic financial transaction system according to the present invention, as shown in the electronic bank account when a customer makes a financial transaction in the bank using the electronic bank account 30 When submitting a document for the transaction with the bank clerk 30, the bank clerk inserts the electronic bank account 30 into the card recorder 42 provided in the bank, and inserts the transaction record data according to the submitted document into the terminal 40. Will be entered.

At this time, the account information and the card number stored in the electronic bank 30 in step S10 is read by the card recorder 42 and then transmitted to the terminal 40, the terminal 40 received the account information and card number in step S12 ) Transmits the account information and the card number to the bank server 20 through the network 50 in step S14 to determine forgery or forgery of the electronic bankbook 30.

Thereafter, the bank server 20 receiving the account information and the card number reads the corresponding card number from the ledger database 22 using the account information received in step S16. In this case, the bank server 20 transmitted from the terminal 40 in step S18. If the account information and the card number match the account information and the card number read from the ledger database 22, and if there is a mismatch, the electronic bankbook 30 read from the card recorder 42 to the terminal 40 in step S20 It outputs that it is illegally copied and ends the transaction.

In addition, if it is determined in step S18 that the account information and the card number transmitted from the terminal 40 coincide with the account information and the card number read from the ledger database 22, the transaction submitted by the customer is determined to be a normal electronic account. The financial transaction is performed according to the record data. At this time, the bank server 20 receives the transaction record data corresponding to the deposit / withdrawal details requested by the customer from the terminal 40 to generate a cryptographic authentication code (MAC). Done.

That is, the process of generating a password authentication code (MAC) after reading the secret authentication code generation secret key corresponding to the account information that the transaction is made in step S22 from the ledger database 22 of the bank server 20 terminal 40 The cryptographic authentication code generator 24 generates a cryptographic authentication code (MAC) using the transaction record data received from the cryptographic authentication code generation secret key as an operation factor.

Then, the bank server 20 stores the transaction record data and the encryption authentication code (MAC) in the ledger database 22 and transmits the encryption authentication code (MAC) to the terminal 40 through the network 50 in step S24. The terminal 40, which has received the encryption authentication code (MAC), stores the encryption authentication code (MAC) together with the transaction record data through the card recorder 42 in the electronic account 30 in steps S26 and S28. .

The electronic bankbook 30 as described above can determine the presence or absence of the modulation using the identifiable card number stored therein, the process first only the account information stored in the electronic bankbook 30 card recorder 42 of the terminal 40 After reading through the network 50 via the bank server 20, and then retrieves the card number corresponding to the account information received from the bank server 20 from the ledger database 22 and then again the network 50 and the terminal When the 40 is transmitted to the electronic bankbook 30 through the card recorder 42, the electronic bankbook 30 outputs only whether the received card number matches the card number stored in the terminal 40 to the terminal 40, and forgery. B informs that the electronic bank account 30 has been tampered with and determines whether or not to stop the transaction.

At this time, since the card number is recorded in the form of a read only mask ROM (ROM) during the manufacture of the electronic bank account 30, even if an attacker illegally changed the account information in the electronic bank account 30, the card number cannot be tampered with.

In addition, financial transactions can be made not only in banks but also in Internet banking, ATMs, personal digital assistants (PDAs), etc. In the case of ATMs, the terminal 40 and the card recorder 42 according to the present invention are viewed as an integrated form. In the case of Internet banking, a personal computer at home or work serves as the terminal 40, and after connecting the card recorder 42 to the personal computer, the customer directly transfers the electronic bank account 30 to the card recorder ( 42) inserting or removing it.

On the other hand, if the transaction record in the electronic bank 30 is manipulated by an attacker, the bank presents the customer information and the digital signature value, the secret key for generating the cryptographic authentication code derived therefrom, and discloses the digital signature value for the bank's digital signature. By verifying using the key, it is possible to prove that the secret key for generating the encryption authentication code is justified.

In addition, since the encryption authentication code (MAC) for the manipulated transaction record is different from the encryption authentication code (MAC) for the legitimate record because the secret authentication code generation secret key is not used, it can be determined whether the operation is performed.

Also, even when the transaction record and the cryptographic authentication code (MAC) are operated together, the secret key for cryptographic authentication code generation is stored only in the ledger database 22 managed by the bank, and is used for the electronic signature of the bank known only by the bank. Since the secret key for generating the password authentication code is generated from the digital signature value signed using the secret key, the attacker cannot generate the secret key for generating the password authentication code. Authentication code (MAC) could not be generated.

In addition, when the electronic bank account 30 is replicated using the account information exposed to others, the duplication can be noticed by the following process.

That is, if only the account information obtained by the attacker is overwritten by another electronic bank account 30, the card number of the electronic bank account is not changed, so that the information stored in the ledger database 22 of the bank server 20 can be matched. No, it is impossible to attack to duplicate the electronic bank account 30.

The present invention is not limited to the above-described embodiment, and of course, modifications may be made by those skilled in the art without departing from the technical spirit of the present invention. For example, in this embodiment, one cryptographic authentication code (MAC) is generated for one transaction record, but one cryptographic authentication code may be generated for several transaction records. In addition, in the present embodiment, the secret key for generating the password authentication code and the password authentication code (MAC) are stored and accessed in the ledger database 22, but in order to further improve the security, it is necessary without storing them in the ledger database 22. It can be created and used in real time and then destroyed.

Therefore, the scope of the claims in the present invention will not be defined within the scope of the detailed description, but will be limited to the claims below.

As described above, the present invention is configured to handle a secret key for generating a password authentication code for generating a password authentication code (MAC) only in a bank server, and generates a password authentication code (MAC) generated through the transaction record data. Since it is configured to store in the electronic bank account, even if an attacker illegally tampered with the transaction record, the password authentication code (MAC) that matches the password authentication code (MAC) handled by the bank server cannot be generated. If it is impossible to use it, and if the attacker makes an assertion that the illegally tampered encryption authentication code (MAC) is justified, the bank verifies the invalid signature authentication code (MAC) by verifying and showing the digital signature value calculated from the customer information. It is possible to prove that it is wrong to claim justification.

In addition, if the account information stored in the electronic bank account is sent to the bank server, and the card number corresponding to the account information is read from the ledger database and transmitted to the electronic bank account, the card number received from the electronic bank account matches the card number stored in itself. It is configured to output only to the terminal, and the card number is recorded in the form of a mask ROM (ROM) which can only be read during the manufacture of the electronic bank account, so that the card number can be altered even if an attacker illegally changes the account information in the electronic bank account. Since there is no financial transaction can not be made due to the mismatch of the card number before the financial transaction, the security is greatly improved.

Claims (21)

delete delete delete delete delete delete delete delete delete delete delete delete In the electronic financial transaction system, It has its own identification information, and stores the account information including previous transaction record data for each of the plurality of accounts used for electronic banking and the corresponding password authentication code, and is used for the financial transactions of each account. ; A terminal including an interface medium for interfacing with the electronic financial transaction medium; And Ledger database for storing the identification information for each of the electronic financial transaction medium, the account information and a secret key for generating a password authentication code to be assigned to each account, and for generating a password authentication code for generating a secret key for generating a password authentication code for each account A secret key generator and a password authentication code generator for generating a password authentication code by using transaction record data for each transaction and a secret key for generating a password authentication code for each account, wherein the encryption authentication code corresponding to the transaction record data is recalled. The electronic financial transaction medium and the ledger database are output to update the account information of each account, and the respective components are configured to perform an electronic financial transaction for each of a plurality of accounts of the electronic financial transaction medium connected to the terminal through a network. Bank server to control the; Electronic financial transaction system comprising a. The method of claim 13, The electronic financial transaction medium Allocate a storage area for each account to store account information, wherein the account information includes previous transaction record data and a cryptographic authentication code generated each time a corresponding transaction occurs. The method of claim 14, The electronic financial transaction medium Electronic financial transaction system, characterized in that the IC card. The method of claim 15, The interface medium And a card recorder for reading or writing data from the IC card. The method of claim 13, The secret key generator for password authentication code generation Generating an electronic signature value using the customer information owning the electronic financial transaction medium and the bank's electronic signature secret key value as an operation factor, and converting the electronic signature value through a secret key derivation machine to generate a secret key for cryptographic authentication code generation. An electronic financial transaction system characterized by the above. The method of claim 17, The bank server An electronic financial transaction system, characterized by storing the secret authentication code generation secret key generated from the secret authentication code generator for the corresponding account of the ledger database and controlling the network transmission impossible. In the electronic financial transaction method using an electronic financial transaction medium having its own identification information and account information for each of a plurality of accounts, A first step of receiving, from the electronic financial transaction medium, account information including its identification information, previous transaction record data of the corresponding account, and a corresponding password authentication code, and the transaction record data; A second step of determining whether the received identification information and account information match the previously stored identification information and account information of the electronic financial transaction medium; A third step of generating a password authentication code corresponding to the corresponding transaction record data by using a secret key for generating a password authentication code of the corresponding account only if the match is found; And storing the account information including the transaction record data and the encryption authentication code corresponding thereto and transmitting the same to the electronic financial transaction medium. The method of claim 19, The second step is And pre-store identification information corresponding to the electronic financial transaction medium and account information for accounts held by the electronic financial transaction medium. The method of claim 19, The third step is Generates an electronic signature value using the customer information owning the electronic financial transaction medium and the bank's electronic signature secret key value as an operation factor, and converts the electronic signature value through a secret key derivation machine to generate a secret key for password authentication code generation by account Electronic financial transaction method comprising the step of storing.