WO2010038913A1

WO2010038913A1 - Preservation method about data in ie memory altered without leave

Info

Publication number: WO2010038913A1
Application number: PCT/KR2008/005808
Authority: WO
Inventors: Hong Seok Kang; Jin Young Jung; Sung Jin Hwang
Original assignee: Softcamp Co., Ltd
Priority date: 2008-10-02
Filing date: 2008-10-02
Publication date: 2010-04-08

Abstract

Disclosed herein is a method of ensuring security against the illegally altered data of Internet Explorer (IE) memory. The method includes a first step of entering data including text in a text field, a second step of encrypting the entered data character by character and entering a corresponding cryptogram in a hidden field, a third step of submitting the data and cryptogram to a server, and a fourth step of decrypting the cryptogram and checking whether the data has been altered. The first step includes a step of selecting one or more pieces of stored data from stored data so as to enter the selected data in the text field and a step of separating the selected stored data into individual characters and detecting the text of the selected stored data. At the second step, the character-by-character encryption of the selected stored data is performed using an event handler.

Description

[DESCRIPTION] [Invention Title]

PRESERVATION METHOD ABOUT DATA IN IE MEMORY ALTERED WITHOUT LEAVE [Technical Field]

The present invention relates to a method of ensuring security against illegally altered IE memory data, which is capable of preventing a user's entered information (data) stored in memory from being illegally altered, thus preventing infringement upon legitimate Internet use, and preventing online communication from being performed against the user's intention. [Background Art]

Internet Explorer (hereinafter referred to as "IE") is a web browser that is the most widely distributed and used of all programs which enable the viewing of information on the World Wide Web (the www). A method for attaining basic communication between a client and a server is constructed based on IE. A security system that is used in the field of Internet communication security, which is a special field, is also constructed on the basis of IE.

Accordingly, IE includes all basic constructions for Internet communication. The operations of a communication program and a security program generally responsible for communication between a client and a server are generally designed to utilize the constructions that are built into IE.

IE memory is used to temporarily store various types of information, entered by a user, so as to send them to a relevant server, and is an element that is indispensable for enabling IE to perform smooth Internet communication.

Meanwhile, since pieces of IE memory are devices through which information entered by users and information sent from servers to clients must pass, such pieces of IE memory are the primary targets of hackers who intend to maliciously intercept or alter information exchanged in communication between clients and servers.

FIG. 1 is a diagram sequentially showing a prior art hacking process using IE memory alteration. Referring to this drawing, the prior art hacking process which targets IE memory will now be described.

Hacking using IE memory alteration is performed to alter the values of general fields, such as account numbers, names and the amounts of money, which are not protected by security programs that run when Internet banking or various types of electronic commerce is being performed.

In greater detail, hacking using IE memory alteration is performed to, when a user transfers money using Internet banking, alter an account number and the amount of money stored in the IE memory and submit the altered account number and amount of money to a Public Key Infrastructure (PKI) communicating with a bank server.

As shown in FIG. 1, when a user enters a transfer account number and the amount of money to be transferred using a keyboard secured through a keyboard security driver, information about the entered transfer account number and amount of money to be transferred is encrypted using the keyboard security driver and transferred to a keyboard security ActiveX controller installed in an operating system, and the keyboard security ActiveX controller decrypts the information and transfers it to the IE memory character by character.

Accordingly, the account number and the amount of money to be transferred which were entered by the user are transferred to the IE memory in their original form.

Thereafter, when normal processing is performed, the account number and the amount of money to be transferred are transferred to the PKI memory of the IE memory, submitted to the PKI, and then decrypted. However, when abnormal processing is performed due to hacking, the account number and the amount of money to be transferred are altered during submission to the IE memory, an account number and the amount of money to be transferred which are different from those entered by the user are stored in the IE memory. As a result, the altered account number and amount of money to be transferred are transferred to the PKI memory after passing through an encryption process, which is a normal process, and are submitted to the bank server, and then a money transfer process is performed.

That is, an account number and the amount of money to be transferred which are different from an account number and the amount of money to be transferred which are entered by the user are transferred to a bank server, so that money is transferred to the different account without the user knowing it. Furthermore, data about the results of processing of the bank server is altered in an order reverse to that of the above-described process, and is then output to a monitor as if bank transactions have been performed according to the user's intention.

FIG. 2 is a diagram sequentially showing a prior art method for ensuring security against illegally altered data so as to prevent IE memory alteration, and FIG. 3 is a diagram showing an example of a web page that is output during Internet banking transactions. A description will be given below with reference to these drawings.

In order to block hacking performed using IE memory alteration, it is necessary to verify the integrity of information entered by a user. A prior art security method uses a hidden field method so as to check the integrity of information entered by the user.

First, in order to enable the smooth performance of the prior art data security method, the creation and exchange of keys for encryption/decryption between the PKI and the keyboard security program are performed and a target for the prevention of memory alteration is set.

That is, the security method of the keyboard security program installed in the client is set in the PKI and IE, so that smooth processing is performed. Furthermore, when application targets related to IE are set, an account number and the amount of memory which are not existing security targets are newly set. Moreover, a setting is made so that, when a security target is entered, a cryptogram corresponding to text which is the security target is created and stored in a hidden field.

When preparations for security have been made by the completion of setting between the keyboard security program, IE and the PKI, the user enters text by manipulating the keyboard.

The web page shown in FIG. 3 shows outputs occurring during Internet banking transactions. The web page posts items that should be entered by the user, such as a sending account number, a sending account password, a receiving account number, a receiving bank, the amount of money to be transferred and a client.

The encryption process starts when a cursor is focused on an item for which the prevention of memory alteration has been applied. Whenever a character corresponding to entered information is entered by the user's manipulation of the keyboard, it is encrypted and recorded in a hidden field in the form of a cryptogram and text entered by the user is output to the text field of the item as it is. In this encryption process, a total of 24 bytes of cryptogram is created in such a way as to add a 1-byte index indicating the sequential position thereof to 1-byte keyboard-entered information (text).

That is, at the same time that the text entered by the user is stored in the IE memory, information obtained by encrypting the corresponding text is entered and stored in a separate hidden field. Using a common submission method, the PKI of the bank server receives and decrypts the text and the information of the hidden field, and compares them with each other. Here, if the text and the information of the hidden field are different from each other, the PKI considers that the alteration of the text resulting from hacking has occurred and then stops normal processing. If they are identical to each other, the PKI enables the user's bank transaction to be performed successfully by performing normal processing.

Meanwhile, since the sequencing is important in correcting the text entered for the item, deletion must be performed in a sequence starting from the most recently entered text. Accordingly, the cursor must be located behind the text and correction must be performed using only a backspace key.

When the backspace key is pressed, the 1-byte text stored in the text field is deleted and, at the same time, the 24-byte cryptogram of the hidden field is deleted in a First In, Last Out (FILO) manner.

As a result, using the above-described method for ensuring security against illegally altered data, the above-described erroneous communication between the client and the server resulting from IE memory hacking is prevented and the illegal alteration of the IE memory is made pointless.

In the meantime, the prior art security method has a limitation in that it cannot be applied to the case where previously stored data (text) is entered. That is, when an entry is made by clicking or selecting a button for 'a frequently used account' or a button for a fixed amount of money, such as 'one million won', 'five hundred thousand won' or 'one hundred thousand won' for the user's convenience, as shown in FIG. 3, a cryptogram to be entered in a hidden field cannot be created.

The prior art security method is performed only when the user inserts data (text) into a text field by manipulating the keyboard separately.

However, in order to overcome the above problem, the blocking of the previous storage of frequently used transfer accounts or the deletion of buttons for fixed amounts of money causes inconvenience, which is contrary to the purport of providing convenience services. Meanwhile, the construction of a new security system capable of overcoming the problem incurs a considerable cost, so that it causes another problem of increasing the burden of a related service provider (a bank).

Accordingly, currently, there is no measure for the prevention of IE memory alteration, except for the case where the user is cautious and then minimizes the harm resulting from the hacking. [Disclosure] [Technical Problem]

Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a method for ensuring security against illegally altered data, which is capable of overcoming the problem of user information entered during communication between a client and a server being altered within IE memory and then maliciously used, and, in particular, is capable of preventing the harm resulting from the alteration of the IE memory when a user enters text by selecting previously stored content. [Technical Solution]

In order to accomplish the above object, the present invention provides a method of ensuring security against the illegally altered data of IE memory including a first step of entering data including text composed of one or more characters in a text field of a web page; a second step of encrypting the entered data character by character and entering a corresponding cryptogram in a hidden field of the IE memory; a third step of submitting the data and cryptogram stored in the IE memory to a server; and a fourth step of decrypting the cryptogram and checking whether the data has been altered by comparing the cryptogram with the data, wherein the first step includes a stored data selection step of selecting one or more pieces of stored data from stored data so as to enter the selected data in the text field of the web page, the data being the data previously stored in the memory; and a selected stored data submission step of separating the selected stored data into individual characters using a keyboard event generation module and detecting text of the selected stored data through the keyboard events using an event handler; wherein at the second step, the character-by-character encryption of the selected stored data is performed using the event handler. [Advantageous Effects]

As described above, the present invention imparts advantages of minimizing a user's inconvenience and improving stability, because the flaw that data may be altered within IE memory during the use of an information entry method using stored data can be overcome by correction and update based on the installation of an ActiveX control without replacing or considerably supplementing an existing expensive security system, and an existing convenient text entry-type service using stored data can be retained. Furthermore, since it is not necessary to reconstruct an expensive security system, a considerable reduction in the costs of implementing security is expected. [Description of Drawings]

FIG. 1 is a diagram sequentially showing a prior art hacking process using IE memory alteration;

FIG. 2 is a diagram sequentially showing a prior art method for ensuring security against illegally altered data so as to prevent IE memory alteration;

FIG. 3 is a diagram showing an example of a web page that is output during Internet banking;

FIG. 4 is a block diagram showing the configuration of a security system according to the present invention;

FIG. 5 is a flowchart sequentially showing a method for ensuring security against illegally altered data according to the present invention;

FIG. 6 is a diagram showing an embodiment of ActiveX component scripts for executing the method of ensuring security against illegally altered data according to the present invention and an application target; and

FIG. 7 is a flowchart showing the alteration checking step of the method of ensuring security against illegally altered data according to the present invention in detail. [Mode for Invention]

The present invention will be described in detail below with reference to the accompanying drawings.

FIG. 4 is a block diagram showing the configuration of a security system according to the present invention, and FIG. 5 is a flowchart sequentially showing a method for ensuring security against illegally altered data according to the present invention. A description will now be given with reference to these drawings.

The method for ensuring security against illegally altered data according to the present invention is performed based on the security system as described below.

In order to describe the method for ensuring security against illegally altered data according to the present invention in greater detail, the security system will be described in conjunction with the method for ensuring security against illegally altered data.

SIl; step of checking focusing on a security target text field, and S12; focusing step

The security system according to the present invention is configured as shown in FIG. 4. The communication between a client 100 and a server 200 is performed on the basis of an existing IE configuration.

A security target checking module 11 checks whether a text field is a security target when the text field is focused on.

Here, text fields that are security targets are items such as a receiving account number, a receiving bank and the amount of money to be transferred, as shown in FIG. 3.

S13; security system execution step

When a text field that is a security target is focused on, the security target checking module 11 executes the security system according to the present invention.

S14; stored data selection step

The security system and security method according to the present invention have been invented to overcome the defects of the prior art hidden field-type security system and method. When the user makes an entry by selecting previously stored data rather than entering text in a text field that is a security target by manipulating the keyboard (refer to FIG. 3), the security system according to the present invention runs.

Accordingly, if the user enters text in a security target text field by selecting stored data, the subsequent step is performed. In contrast, if text is entered by manipulating the keyboard, the execution of the security method according to the present invention is stopped, and the prior art security method (hidden field method) is performed in its original form.

That is, the detection of the performance of the latter process and the termination of the procedure at the stored data selection step S14 does not means that the entire procedure of the security system is terminated, but means that only the security system and method of the present invention that has been applied to the prior art security method (the hidden field method) are terminated. Accordingly, the prior art security method (the hidden field method) is normally performed continuously.

In the meantime, the security method according to the present invention may be performed separately from the prior art security method. That is, the security method according to the present invention may be separate from the prior art security method that is performed when the user directly enters text in a security target text field by manipulating the keyboard. Accordingly, the security method according to the present invention may be applied both to a system to which only a method of entering stored data in a text field by selecting the stored data has been applied and to a system to which a method of entering data in a text field through the user's direct manipulation of the keyboard and the method of selecting stored data have been applied.

S15; selected stored data submission step

One piece of stored data stored in memory 30 in script form is selected at the stored data selection step S15, and a keyboard event generation module 12 checks the selected stored data character by character.

That is, when the user selects Gil-dong Go's receiving account number 2345678-123-123456 as shown in FIG. 3, the keyboard event generation module 12 checks the text of "2345678-123-123456," which constitutes the receiving account number, character by character. S16; character-by-character keyboard event generation step When the security system according to the present invention is installed, an event handler 21 operating in conjunction with the keyboard event generation module 12 is registered in a web page 20, and the keyboard event generation module 12 generates a keyboard event for each character according to the text (receiving account number) of the checked stored data, so that the event handler 21 can check it.

As a result, the event handler 21 of the web page 20 checks and processes a keyboard event generated by the keyboard event generation module 12.

S17; data output step

Meanwhile, the keyboard event generated by the keyboard event generation module 12 is transferred to a text field output module 22, and a procedure identical to that of the case where the user makes an entry by directly manipulating the keyboard is performed. Accordingly, although the user selects stored data instead of making entries, that is, rather than directly entering text in a security target text field, the data is sequentially output to the corresponding text field through the text field output module 22.

Accordingly, "2", "3", "4", ^••• of "2345678-123-123456," which is the receiving account number, are sequentially output character by character.

Additionally, output original text is stored in the IE memory 25.

Here, the text field output module 22 is formed by functionally modularizing the construction of the existing IE for outputting text onto a screen.

S18; character-by-character encryption step, and S19; encryption recording step

Meanwhile, the event handler 21 detects a corresponding character by checking the keyboard event generated by the keyboard event generation module 12, encrypts the detected character, and stores it in the hidden field of the IE memory 25 through the hidden field entry module 23.

FIG. 6 is a diagram showing an embodiment of ActiveX component scripts for executing the method of ensuring security against illegally altered data according to the present invention and an application target. Referring to this drawing, the embodiment of the present invention will now be described.

(D is a script that is used to install an ActiveX control for configuring the security system according to the present invention and to set a specific normal text field as a target for the prevention of memory alteration.

(2) When a user clicks a button, a cursor is focused on a normal text field and the security system according to the present invention is performed. Meanwhile, the previously stored data "123" is a script that performs a transfer to SetData O, which is a keyboard event generation function.

It is apparent that it is possible to focus a cursor on a corresponding normal text field using a mouse.

(3) The text "123" is read character by character and, at the same time, keyboard events are generated. Then, "1", "2" and "3" are sequentially output into the normal text field.

® Corresponding characters are encrypted at the same time that the keyboard events are generated, and then a cryptogram is added to the hidden field of the IE memory.

S20; completion confirmation step

As described above, when the original text received from the keyboard event generation module 12 is sequentially output to the text field and the event handler 20 detects and encrypts the characters and enters them in the hidden field of the IE memory 25, it should be confirmed that the entire text has been output and entered and the following procedure should be performed.

With a method for the confirmation, the completion of the entry of the text can be confirmed by clicking a 'button', as shown in FIG. 6. The text and cryptogram have been stored in the IE memory 25 by clicking the 'button'.

S21; alteration checking step

The alteration checking step is the step of checking whether the text and cryptogram stored in the IE memory 25 have been altered. A detailed description of this step will be given later.

S22; data and cryptogram submission step

An entered information submission module 26 submits the data of a text field and the cryptogram of a hidden field stored in the IE memory 25 to the corresponding server 200.

As described above, the server 200 may be a bank server, and the secure submission of the submitted data and cryptogram may be performed using the prior art method (PKI method).

In the diagram of FIG. 4, the prior art construction for securing the submission is omitted. When the data and cryptogram are submitted using the entered information submission module 26, the prior art secure submission method will be used in its original form.

S23; step of comparing the cryptogram with the data after decryption An entered information comparison module 27 installed in the server 200 receives the data and cryptogram submitted by the client 100, decrypts the cryptogram, and compares the cryptogram with the data.

If, as the result of the comparison, the data and the decrypted cryptogram are determined to be identical with each other, it is considered that alteration has not been performed within the IE memory 25 and then the subsequent steps will be normally performed. In contrast, if it is determined that the data and the decrypted cryptogram are different from each other, the data is considered to have been altered within the IE memory 25, an error message is output, and then the performance of the corresponding procedure is stopped.

As a result, the user can prevent harm that may be caused by the illegal alteration of data stored in the IE memory 25.

Furthermore, since the user can prepare for alteration while retaining the method of making an entry by selecting stored data rather than entering text by directly manipulating the keyboard, the user has an advantage of performing stable transactions while retaining the conventional benefits thereof.

FIG. 7 is a flowchart showing the alteration checking step of the method of ensuring security against illegally altered data according to the present invention in detail. Referring to this drawing, a description of the flowchart will be given below.

The alteration checking step S21 according to the present invention will be described in detail below.

After the data and the cryptogram are normally entered and stored in the IE memory 25 at the completion checking step S20, the integrity of the data should be ensured by periodically checking the data before submission to the server 200.

The data composed of text entered in a text field and stored in the IE memory 25 as described above may be altered within the IE memory 25 by a hacker using the prior art hacking method. Furthermore, the cryptogram may be also altered using the keyboard event generation module 12. Accordingly, it is preferable to, before submitting the data to the server 200, ensure communication between the client 100 and the server 200 by checking whether the data has been altered.

Since the keyboard event generation module 12 is provided through a separate interface, it may be altered from the outside. Accordingly, even data present after the formation of a cryptogram may be altered by hacking even before or after being stored in the IE memory 25.

As a result, it is necessary to periodically check data after the corresponding data has been entered. S21a; step of encrypting the output text of the text field The data (the output text of the text field) stored in the IE memory 25 is copied, and is periodically encrypted by the encryption module 24. Here, the encryption of the data is performed using an encryption method identical to that of a cryptogram entered in the hidden field, so that it is possible to determine whether the data is identical to the cryptogram of the hidden field that is paired with the corresponding data.

S21b; cryptogram comparison step, and S21c; identity verification step The encrypted data is compared with the cryptogram that is paired with the data. Here, since the encryption method of the cryptogram entered in the hidden field is identical to that of the data stored in the IE memory 25, the identity between the cryptogram of the data and the cryptogram of the hidden field is verified by comparing them with each other.

If, as a result of the verification, the two cryptograms are identical to each other, the subsequent normal procedure is performed.

S21d", error message output step

If, as a result of the comparison, the two cryptograms are different from each other, the data stored in the IE memory 25 is considered to have been illegally altered by hacking, an error message is output, and then the performance of the procedure is stopped.

The above-described alteration checking step S21 is repeated one or more times until the data and cryptogram are submitted to the server 200 by the entered information submission module 26. Accordingly, the method for ensuring security against illegally altered data according to the present invention can ensure the integrity of entered data through a keyboard event generation function.

Claims

[CLAIMS]

[Claim 1]

A method of ensuring security against illegally altered data of Internet Explorer (IE) memory including a first step of entering data including text composed of one or more characters in a text field of a web page; a second step of encrypting the entered data character by character and entering a corresponding cryptogram in a hidden field of the IE memory; a third step of submitting the data and cryptogram stored in the IE memory to a server; and a fourth step of decrypting the cryptogram and checking whether the data has been altered by comparing the cryptogram with the data, wherein the first step comprises a stored data selection step of selecting one or more pieces of stored data from stored data so as to enter the selected data in the text field of the web page, the data being the data previously stored in the memory; and a selected stored data submission step of separating the selected stored data into individual characters using a keyboard event generation module and detecting text of the selected stored data through the keyboard events using an event handler; wherein at the second step, the character-by-character encryption of the selected stored data is performed using the event handler.

[Claim 2]

The method as set forth in claim 1, further comprising, before the third step, a data output step of sequentially entering the selected stored data, which is separated into the individual characters at the selected stored data submission step, in the text field of the web page.

[Claim 3]

The method as set forth in claim 1 or 2, further comprising, between the second step and the third step, a alteration checking step of verifying identity between the stored data entered in the IE memory and the cryptogram entered in the hidden field by comparing the entered stored data with the entered cryptogram one or more times.

[Claim 4] The method as set forth in claim 3, wherein the alteration checking step comprises: an encryption step of copying the stored data entered in the IE memory and encrypting the stored data according to the encryption criterion of the second step; a cryptogram comparison step of verifying a cryptogram obtained at the encryption step with the cryptogram entered in the hidden field; and an error output step of, if there is no identity at the cryptogram comparison step, outputting an error message.