KR20190101118A - Apparatus and method to encrypt key input in document object model level - Google Patents

Abstract

Disclosed are an apparatus for encrypting key input in a document object model (DOM) level and a method thereof. The apparatus for encrypting key input in a DOM level interprets a web page file of a web page in the DOM level to generate a DOM tree structure, sets an encryption mode in accordance with a type of a key event, sets a flag so that the key even generated after setting the encryption mode is not to propagated to a target object or propagated to the outside, and encrypts and stores user input inputted after setting the encryption mode.

Description

Apparatus and method for key object encryption at document object model level {APPARATUS AND METHOD TO ENCRYPT KEY INPUT IN DOCUMENT OBJECT MODEL LEVEL}

The present invention relates to an apparatus and method for encrypting user input in an Internet environment, and more particularly, to an apparatus and method for encrypting a key input at a Document Object Model (DOM) level.

Currently, in the Internet environment where personal information may be exposed such as hacking, security of information input by a user is realized in various ways. A good example is keyboard security solutions. Keyboard security solution is a solution that encrypts sensitive information such as ID and password that a user inputs using the keyboard and protects it from hacking.

As a specific example of a keyboard security solution, a user executes a security program that allows a user to enter a password for Internet banking using a mouse instead of a keyboard, and selects a password from a numeric screen provided by the security program. Currently, a separate active-X program is required to use this security program.

As such, the current keyboard security solution is cumbersome to have a security program and an ActiveX program for keyboard security, and even in that use, there is a hassle of having to click each mouse after executing the security program.

In addition, current keyboard security solutions are executed by JavaScript, which executes the user's input already entered in the Document Object Model (DOM), for example, a password, etc. in the corresponding object of the HTML or XML document. This is done after propagation to (Object). Therefore, when event propagation is performed between objects of the DOM tree structure generated by the document object model, there is a problem in that hooking may be generated to intercept an externally propagating event.

An object of the present invention is to provide an apparatus and method for encrypting a key input at a document object model level for encrypting user input in a document object model.

Another object of the present invention is to provide an apparatus and method for encrypting a key object at a document object model level, which prevents hooking in the document object model by preventing user input from being propagated to the object in the document object model hierarchy. will be.

In addition to the above object, embodiments according to the present invention can be used to achieve other objects not specifically mentioned.

According to an embodiment of the present invention for solving the above problems, a key input encryption apparatus of a document object model level is provided. The key input encryption apparatus includes a key input unit for receiving a user input input through an input means, a key event identification unit for identifying a key event corresponding to the user input input through the key input unit, and identifying a target object corresponding to the event; When the web page file of the new web page is received from the server, the web page file is interpreted to generate the DOM tree structure, and after setting the encryption mode according to the type of key event, the user input that is input is propagated to the target object, or Do not propagate, the DOM unit to encrypt the user input input after setting the encryption mode, the encryption unit for encrypting the user input received from the DOM unit and storing the encrypted encryption value, the encryption encrypted by the encryption unit Storage unit for storing the value, and Internet communication between the user terminal and the server It includes a communication unit.

The encryption unit encrypts a plurality of sequentially input user inputs using a symmetric key. If there is a previously encrypted encryption value, the encryption unit decrypts the encryption value and then replaces the previously input user input with the currently input user input. Merge and merge user input using symmetric keys.

The encryption unit encrypts and stores the first user input so that a mark not related to the first user input is displayed on the screen of the user terminal.

The DOM unit prevents the user input received after setting the encryption mode from being propagated to the <html> object and the object after the <html> object, and the event propagation from the object of the DOM tree structure to the outside.

When the server receives the encrypted cipher value, the encrypted symmetric key and the identification information, the server may decrypt the encrypted cipher value through the servlet filter. According to an embodiment of the present invention for solving the above problems, An object model level keystroke encryption method is provided. This keystroke encryption method involves creating a DOM tree structure by interpreting a webpage file of a webpage at the Document Object Model (DOM) level, setting the encryption mode according to the type of key event at the DOM level, and at the DOM level. The setting of the encryption mode includes setting a flag so that the generated key event is not propagated to the target object or propagated to the outside, and encrypting and storing a user input input after setting the encryption mode at the DOM level.

The encrypting and storing of the user input may include encrypting a plurality of user inputs sequentially input by using a symmetric key, and decrypting the encryption value if there is a previously encrypted encryption value and then previously inputting the user. Combine the input with the currently entered user input and encrypt the combined user input using a symmetric key.

In the encrypting and storing of the user input, after encrypting and storing the user input, a mark not related to the first user input is displayed on the screen of the user terminal.

According to an embodiment of the present invention, security for user input is possible without using a separate security program, and an ActiveX program does not need to be installed.

In addition, according to an embodiment of the present invention, the user input is not propagated to the object of the document object model tree structure to enable higher keyboard security.

1 is a diagram illustrating a general DOM tree structure and an event propagation model.
2 is a block diagram of a key input encryption device of a document object model level according to an embodiment of the present invention.
3 is a general flowchart of a key input encryption method of a document object model level according to an embodiment of the present invention.
4 is a flowchart illustrating a real-time encryption method according to a user input according to an embodiment of the present invention.
5 is a diagram illustrating a specific example of a real-time encryption method according to a user input according to an embodiment of the present invention.
6 is a diagram for explaining a DOM tree structure and an event propagation model according to an embodiment of the present invention.
7 is a diagram illustrating a servlet filter according to an exemplary embodiment of the present invention.
8 is a diagram illustrating a network encryption / decryption process of a servlet filter according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. The drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification. In addition, in the case of well-known technology, a detailed description thereof will be omitted.

In the present specification, when a part is said to "include" a certain component, it means that it may further include other components, without excluding the other components unless otherwise stated. In addition, the terms “… unit”, “module”, etc. described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware or software, or a combination of hardware and software.

Hereinafter, an apparatus and method for encrypting a key input of a document object model level according to an embodiment of the present invention will be described with reference to the accompanying drawings.

1 is a diagram illustrating a general DOM tree structure and an event propagation model. In general, when a user terminal accesses a server, the web page of the user terminal analyzes a web page corresponding to the domain address of the server to display the web page on the screen of the user terminal. These web browsers use the Document Object Model (DOM), Browser Object Model (BOM), and JavaScript to interpret web page files such as HTML files and XML files.

For example, the document object model creates a DOM tree structure for HTML (or XML) provided by the server to enable JavaScript to interpret web page files such as HTML files and XML files. An example of the DOM tree structure generated at this time is shown in FIG. 1. 1 is a diagram illustrating a general DOM tree structure and an event propagation model.

As shown in FIG. 1, a document object model generally parses an HTML file and performs objectization on tags such as <html>, <body>, <tbody>, <tr>, and <td>, respectively. And make each object a hierarchical structure, or tree structure. This tree structure is called DOM tree structure.

In this DOM tree structure, when a key event is generated by user input such as keyboard, mouse, or touch, the generated event is propagated to each object in the DOM tree structure to generate a target object, that is, an event. It is propagated to the DOM object corresponding to the element or to the parent object of the target object. This process of event flow is called event flow.

The event flow goes through three phases: the capturing phase, the target phase, and the bubbling phase. For each step, for example, when an event occurs in the <td> object hatched in FIG. 1, the event is first passed from the browser's 'Defaultview' to the 'Document' object, which is the parent object of the <td> in which the event occurred. passed to <tr> At this time, the event flow delivered from the 'Document' object to the <tr>, the parent object of the <td> where the event occurred, is called a capturing step.

The target stage is the flow of events from <tr>, the parent object of <td> where the event is raised, to the target object <td>, and the bubbling stage is the <td, the next parent object, after the event is delivered to the target object. Event flows from> to <Document> object.

According to this general flow of events, for example, when the password input object is a hatched <td> object during Internet banking, the password entered by the user is recorded in the target object <td> according to the above-described event flow. It is then provided to the server by JavaScript running a Keyboard Security program or Keyboard Security ActiveX via a <Document> object.

In this case, since the inside of the DOM tree structure is not encrypted and only blocks access to the DOM area, the user input information may leak by hacking the storage area itself such as the storage unit of the user terminal or the storage unit of the server. In addition, an event flow occurs in the DOM tree structure such as a capture step, a target step, and a bubbling step. During this event flow, a hook may be intercepted from the outside, and user input information may leak through the hook. have.

However, according to an embodiment of the present invention, by encrypting the inside of the DOM tree structure, real-time encryption is performed on the user input at the document object model level, stored in the user terminal, server, etc., and user input in which encryption is performed in real time. The propagation flag is set so that it is not propagated to the corresponding object in this DOM tree structure so that at least the capture and bubbling steps are not performed when key events (eg user input) are delivered to the DOM tree structure.

2 is a block diagram of a key input encryption device of a document object model level according to an embodiment of the present invention. Referring to FIG. 2, the key input encryption apparatus 100 according to the embodiment of the present invention is mounted in the user terminal A. FIG. The user terminal A is a terminal capable of data communication with the server 200 by connecting to the Internet by wire or wirelessly, and may be, for example, a smartphone or a computer.

The key input encryption apparatus 100 includes a key input unit 110, a key event detecting unit 120, a DOM unit 130, an encryption unit 140, a storage unit 150, and a communication unit 150.

The key input unit 110 receives a user input that is input through an input means such as a keyboard, a mouse, or a touch. The key event grasping unit 120 grasps the type of the user input, ie, the key event, input through the key input part 110. The key event may be a text input event such as a number or a letter or an command execution event. The key event identifying unit 120 may identify a target object corresponding to an element generating the corresponding key event in the DOM tree structure.

The DOM unit 130 performs the operation of the document object model and when the encryption for the user input is required so that the user input is encrypted in association with the encryption unit 140. When the user input is encrypted, the <html> Do not propagate below or outside the object. Specifically, when the DOM unit 130 receives a new web page, that is, a new HTML (or XML) file from the server 200, the DOM unit 130 interprets the corresponding HTML (or XML) to generate a DOM tree structure. After generating the DOM tree structure, the DOM unit 130 propagates an event (including user input received from the key input unit 110) to a sub-object of the <html> object, that is, an element according to whether the propagation mode or the propagation blocking mode is used. Blocks propagation

The propagation mode or the radio wave blocking mode is set at the request of the user, the server administrator, or the like, or automatically set and terminated according to the type of event. As an example of automatically setting and canceling, when an event requiring security is generated, a radio wave blocking mode is set for a predetermined number of user inputs (for example, three user inputs) input after the event occurs.

Of course, the jamming mode is associated with the encryption unit 140. When the radio wave blocking mode is set, the input number of user inputs is provided to the encryption unit 140 to encrypt the corresponding user inputs. The propagation mode is an operation of a normal document object model, so detailed description thereof is omitted.

The encryption unit 140 encrypts a user input received from the DOM unit 130 or the key event checking unit 120, stores an encrypted encryption value (user input), and transmits the user input to the server 200. The encryption value stored at the time of occurrence is provided to the server 200. The encryption unit 140 may display the encrypted user input and other information (for example, dummy numeric information when the user input is a number) to deceive the user input displayed on the screen of the user terminal A. At this time, the information displayed on the screen is the same length as the user input.

The storage unit 150 stores the encrypted value (user input) encrypted by the encryption unit 140.

The communication unit 160 is in charge of internet communication between the user terminal A and the server 200. The communication unit 160 may transmit the encryption value to the server 200 through a servlet filter executed on the web. Hereinafter, an operation of the key input encryption apparatus, that is, a key input encryption method, will be described with reference to FIGS. 3 to 6.

3 is a general flowchart of a key input encryption method of a document object model level according to an embodiment of the present invention. Referring to FIG. 3, when the user terminal A accesses the server 200, the DOM unit 130 may include a web page such as an HTML (or XML) file for a web page of a domain address connected from the server 200. Receive a file (S301).

The DOM unit 130 generates a DOM tree structure by analyzing the received web page file such as an HTML (or XML) file (S302). An example of the generated DOM tree structure is shown in FIG. 6.

After the DOM tree structure is generated, a key event is generated when a user performs an input using a keyboard, a mouse, a touch, etc. The key input unit 110 receives a user input manipulated by the user and uses the key event checker ( 120) (S303).

The key event grasping unit 120 grasps the type of the event and the target object according to the received user input and informs the DOM unit 130 of the target object (S304). In this case, when the user input is propagated to the target object in the propagation mode, the key event identifying unit 120 provides the user input to the DOM unit 130.

The DOM unit 130 determines the type of the received event to determine whether the event type is an event that requires encryption for user input (S304), and sets an encryption mode in case of an event requiring encryption and sets it as a target object. The event is propagated (S306). The DOM unit 130 blocks a flow of events by setting a flag to block the capturing step and the bubbling step in response to the encryption mode setting (S307). On the other hand, if the type of the received event is an event that does not require encryption, the DOM unit 130 maintains the normal mode and performs the operation of the general document object model (S305).

After the encryption mode is set in the DOM unit 130, when a user inputs a user input such as a password (eg, text or characters), the user is provided to the DOM unit 130 through the key event identifying unit 120 (S308). .

As shown in FIG. 6, the DOM unit 130 prevents the user input received from the 'Defaultview' as the 'Document' object to be propagated to the sub-object, and also propagates information or events from the sub-object to the 'Document' object. After doing so, the user input is provided to the encryption unit 140. The encryption unit 140 encrypts and stores the user input according to the instructions of the DOM unit 130 (S309).

The encryption unit 140 generates and outputs a random value corresponding to the user input so that the user input is not exposed on the screen (S310), and the random value is displayed on the screen by JavaScript (B). Here, the random value corresponds to a dummy value.

Here, the encryption operation of the encryption unit 140 will be described in more detail with reference to FIGS. 4 and 5. 4 is a flowchart illustrating a real time encryption method according to a user input according to an embodiment of the present invention, and FIG. 5 is a view illustrating a specific example of a real time encryption method according to a user input according to an embodiment of the present invention.

4 and 5, when the user sequentially inputs alphabets “a, b, and c”, the encryption unit 140 first receives the alphabet “a” (S401). The encryption unit 140 encrypts the alphabet 'a' using a symmetric key (that is, an encryption key) shared with the server 200 to generate a ciphertext 1 that is an encryption value (S402), and stores the ciphertext 1 in the storage unit ( 150) (S403).

Here, the symmetric key is generated by the server 200 or generated by the user terminal (A). Alternatively, the server 200 and the user terminal A exchange the randomly generated value in the server 200 and the randomly generated value in the user terminal A in a Diffie-Hellman key exchange method. By exchanging, the symmetric key can be shared but is not limited thereto. The encryption unit 140 generates the ciphertext 1 using the symmetric key, generates a random first display to be displayed on the screen of the user terminal A in place of the alphabet 'a', and then displays the first display in JavaScript. To be displayed on the screen. Here, the first display is a random display irrespective of the alphabet 'a', and is a letter 'e' different from 'a', a special character, an emoticon, or the like. The first display is preferably the same length as the alphabet 'a'.

Then, if the user enters the alphabet 'b', the encryption unit 140 receives the alphabet 'b' (S404). Then, the encryption unit 140 decrypts the ciphertext 1 stored in the storage unit 150 using a symmetric key to make 'a' (S405), and combines the decrypted 'a' and the received 'b' to form 'ab'. After the 'ab' is encrypted using the symmetric key shared with the server 200 generates a cipher text 2 (S406), and stores the cipher text 2 in the storage unit 150 (S407).

The encryption unit 140 generates the cipher text 2 and generates a second display to be displayed on the screen of the user terminal A as a random value instead of the alphabet 'b', and then provides the second display to the JavaScript to display on the screen. To be displayed. Like the first display, the second display is a random display irrespective of the alphabet 'b'. The second display is an alphabet 'f' different from 'b', a special character emoticon, or the like, and preferably has the same length as the alphabet 'b'.

Finally, when the user inputs the letter 'c', the encryption unit 140 receives the letter 'c' (S408). Then, the encryption unit 140 decrypts the ciphertext 2 stored in the storage unit 150 using a symmetric key to make 'ab' (S409), and combines the decrypted 'ab' and the received 'c' to form 'abc'. After the 'abc' is generated using the symmetric key shared with the server 200 generates a cipher text 3 (S410), and stores the cipher text 3 in the storage unit 150 (S411).

The encryption unit 140 generates a ciphertext 3 and generates a third display to be displayed on the screen of the user terminal A as a random value instead of the letter 'c', and then provides the third display to the JavaScript on the screen. To be displayed. The third display is a random display irrelevant to the alphabet 'c' like the first and second displays. The third display is a letter 'g' different from 'c', a special character emoticon, etc., and the same length as the alphabet 'c'. Good.

3 again, if the user requests the user input transmitted to the server 200 (S311), the DOM unit 130 releases the set encryption mode and sets the normal mode (S312). Then, the DOM unit 130 throws the stored cipher text 3 as JavaScript and the JavaScript, that is, the web browser transmits the encrypted symmetric key together with the cipher text 3 to the server 200 (C).

Here, the symmetric key can be encrypted with the public key of the server.

In the above-described embodiment, 'a', 'ab' or 'abc' has been described as being encrypted at the same time using the same large key. However, the cipher text may be generated by encrypting one or more user inputs with different symmetric keys.

When the communication unit 160 transmits the ciphertext 3 and the encrypted symmetric key to the server 200, identification of the encrypted keyboard input value through the servlet filter located in the network section with the server 200 is decrypted. May contain information.

Here, the servlet filter represents a class of servlets that are sandwiched and executed in various operations, and are formed in a chain structure. For example, the servlet filter intercepts actions or data before or after the user request page is executed on the web to perform a preset task, and to prevent or skip the page.

7 is a diagram illustrating a servlet filter according to an embodiment of the present invention, and FIG. 8 is a diagram illustrating a network encryption / decryption process of a servlet filter according to an embodiment of the present invention.

As shown in FIG. 7, the servlet filter 300 may perform a function differently depending on which position in the network section of the server 200 is installed.

For example, when the servlet filter 300 is installed after the network section encryption / decryption filter of the server 200, the servlet filter 300 may perform an encrypted keyboard input value decryption function. On the other hand, when the servlet filter 300 is installed at the front end of the server 200, the servlet filter 300 may perform a network section encryption / decryption function.

Here, when the servlet filter 300 is installed after the network section encryption / decryption filter of the server 200, the key input encryption apparatus 100 may transmit the encrypted keyboard input value (encryption value) and identification information together. The identification information is for performing decoding in the servlet filter 300 and may be represented by using, for example, an arbitrary prefix.

When the encrypted keyboard input value including the identification information is received as described above, the servlet filter 300 may perform decryption using the value shared from the user terminal A as a decryption key.

Meanwhile, FIG. 8A is a screen illustrating an encryption module script redefined to perform encryption of a network section, and (b) is a screen illustrating decryption of a network section through an API to perform encryption of the network section. Indicates.

As shown in FIG. 8, when the servlet filter 300 is installed at the front end of the server 200, the servlet filter 300 redefines encryption module scripts (functions and XHR classes) to perform encryption or redefines decryption APIs and XHR classes to decrypt them. Function can be performed. Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements have been made by those skilled in the art to which the present invention pertains. Belongs to.

A: user terminal 100: key input encryption device
110: key input unit 120: key event grasping unit
130: DOM portion 140: encryption portion
150: storage unit 160: communication unit
200: server 300: servlet filter

Claims (10)

A key input unit which receives a user input input through an input means,
A key event grasping unit which grasps a key event corresponding to a user input input through the key input unit and a target object corresponding to the event;
When a web page file of a new web page is received from the server, the web page file is interpreted to generate a Document Object Model (DOM) tree structure, and the user entered after setting the encryption mode according to the type of key event. A DOM unit that prevents input from being propagated to the target object or to the outside, and encrypts the input of the user input after setting the encryption mode;
An encryption unit for encrypting a user input received from the DOM unit and storing an encrypted encryption value;
A storage unit for storing the encrypted value encrypted by the encryption unit, and
Communication unit in charge of Internet communication between the user terminal and the server
Key input encryption device of the document object model level comprising a. In claim 1
The encryption unit encrypts a plurality of user inputs sequentially input by using a symmetric key. If there is a previously encrypted encryption value, the encryption unit decrypts the encryption value and then inputs the previously input user and the currently input user input. Key input encryption device of document object model level that combines and combines user input using symmetric key. The method of claim 1 or 2,
And encrypting and storing the first user input, thereby encrypting a representation unrelated to the first user input on a screen of the user terminal. In claim 3,
The DOM unit prevents a user input received after setting the encryption mode from being propagated to the <html> object and the object after the <html> object, and further, the event is not propagated to the outside from the object of the DOM tree structure after setting the encryption mode. A keystroke encryption device at the document object model level. The method of claim 4, wherein
The server,
And a document object model level key input encryption device that decrypts the encrypted encryption value through a servlet filter when the encrypted encryption value, the encrypted symmetric key, and the identification information are received.
Creating a DOM tree structure by interpreting the webpage files of the webpage at the Document Object Model (DOM) level,
Setting an encryption mode according to a type of key event at the DOM level,
Setting a flag so that a key event generated when setting the encryption mode at the DOM level is not propagated to a target object or propagated to the outside; and
Encrypting and storing a user input input after setting the encryption mode at the DOM level
Document object model level keystroke encryption method comprising a.
In claim 6,
Encrypting and storing the user input,
Encrypts a plurality of user inputs sequentially by using a symmetric key, and if there is a previously encrypted encryption value, decrypts the encryption value and then merges and combines the previously input user input with the currently input user input. A method of encrypting keystrokes at the document object model level, which encrypts user input using symmetric keys. In claim 6 or 7,
Encrypting and storing the user input,
And encrypting and storing a user input so that a mark irrelevant to the first user input is displayed on the screen of the user terminal. In claim 8,
The setting of the flag includes:
Document object that prevents the user input received after setting the encryption mode to the <html> object and the object after the <html> object, and does not propagate events from the object of the DOM tree structure to the outside after setting the encryption mode Model-level keystroke encryption method.
The method of claim 9,
Transmitting the encrypted encryption value and the encrypted symmetric key to a server,
The server,
And receiving the encrypted cipher value, the encrypted symmetric key, and the identification information, and decrypting the encrypted cipher value through a servlet filter.

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