KR20020074344A - Method and system for restricting access to specific internet sites and LAN card for the same - Google Patents

Abstract

PURPOSE: A harmful site blocking system, method and LAN card is provided to store a list of harmful sites at a memory of a LAN card, to check if a packet, passing through the LAN card, is included in the list, and to send a query to a harmful site list providing server if a user wants to access a web site not included in the list. CONSTITUTION: The method comprises steps of temporarily stopping a packet transmission of a LAN card and extracting a destination address(IP or URL) of a corresponding process target packet(S110), storing the temporarily stopped packet at a packet transmission queue(S120), comparing the extracted destination address with latest connected addresses stored at a buffer(S130), in a case that the extracted destination address is included in the latest addresses or is classified in a non-harmful site list, passing the packet(S180), transmitting a message of "not existing address" to a user computer in a case that the extracted destination address is included in the latest addresses or is classified in a harmful site list(S170), storing the destination address at the buffer and checking if the destination address is included in the harmful site list in a case that the destination address is not included in the latest connected addresses(S140), checking if the destination address is included in the non-harmful site list in a case that the destination address is not included in the harmful site list(S150), and asking a query to a harmful site information providing server if the destination address is a harmful site in a case that the destination address is not included in the non-harmful site list(S160).

Description

Method and system for blocking access to harmful sites and LAN card for him {Method and system for restricting access to specific internet sites and LAN card for the same}

The present invention relates to a method and apparatus for blocking access to a harmful site, and a LAN card for the same. More specifically, a packet to and from a harmful site is included for all packets passing through the LAN card with a memory recording a list of harmful sites on the LAN card. Access to sites not listed in this list is related to a method and device for blocking access to harmful sites and a LAN card for blocking access to harmful sites by querying a harmful site list providing server to determine whether harmful sites are present. .

The Internet is an open computer communication network that enables companies, research institutes, libraries, schools, and individuals around the world to use computers to search and exchange information with each other. The trend is spreading rapidly.

On the other hand, while the Internet is proliferating and the number of users is increasing rapidly, there is a problem that serious social side effects occur due to various harmful information provided to the client from the server on the Internet.

Harmful sites on the Internet are not only sites that provide sexually explicit information such as pornographic images, novels, chats, sites that provide non-social information such as suicide methods and bomb-making methods, but also day trading or chatting during business hours. It refers to various sites that bring work loss by doing.

By accessing these harmful sites, young people are hampered by studying, causing crimes, violence, sexual activity, and suicidal thoughts.

Therefore, various methods for preventing access to harmful Internet information have been introduced.

One such method is to prevent Internet Service Providers (ISPs) from accessing harmful sites. In this method, as shown in FIG. 1A, the Internet service provider 30 prepares a list database 35 of harmful sites, and accesses the users 10a..10n or modems connected to the LAN 20. By monitoring the Internet address input by the users 11 connecting through the telephone network 25 to prevent access to the Internet address published in the list database 35 of the harmful site.

However, this method not only raises the issue of censorship of information, but also prevents access to harmful sites according to the specificity of each user group. The disadvantage is that you lose.

As a result, autonomous control in accordance with the judgment of each user group (school, work, home) rather than ISP is becoming a general trend.

In order to solve this problem, a method of installing the blocking software on each computer 10 may be used. In this method, when the blocking software is installed in each computer 10 as shown in FIG. 1B, the blocking software periodically downloads the blocking site list from the server 50 providing the blocking site list updating service, and then the computer 10 The blocked site list database 35 is constructed in the inside. Then, each time a user accesses an Internet site, the user checks whether the corresponding Internet address matches a site address stored in the blocked site list database 35, thereby preventing access to a site listed in the blocked site list.

However, according to this method, there is a disadvantage in that the removal of blocking software installed on the hard disk or the use of another operating system is inevitable. In addition, the modification of the registry may remove the function of the blocking software, so the blocking effect may vary depending on the parent's computer use ability.

Another way to block harmful sites is to install harmful site blocking software on server computers in a LAN environment. In this method, if the harmful site blocking software is installed on the server computer 21 of the LAN 20 and the block list 35 is provided, the users 10a..10n can access the Internet site. Each time the connection is made, the server 21 checks the data packet and checks whether the corresponding Internet address matches the site address stored in the blocked site list database 35, thereby preventing access to the sites listed in the blocked site list. .

However, this method cannot operate properly when the server computer is powered off or fails, and there is a problem that the Internet speed is reduced by checking data packets on the server. In addition, it requires a manager of a server computer and requires a server computer to be expensive. In addition, there is a disadvantage that individual users who are not in a LAN environment cannot use the method.

In addition, there is a blocking method using a firewall, but this method also has disadvantages in that the cost of purchasing the firewall and filtering system is excessive and cannot be used by individual users.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a method and system that can block access to a harmful site and a LAN card therefor.

Another object of the present invention is to provide a method and system for blocking access to a harmful site that can operate independently of an operating system or a system, a system registry, and the like, and a LAN card therefor.

Another object of the present invention is to provide a method and system for blocking access to harmful sites and a LAN card therefor, capable of minimizing Internet speed degradation due to site blocking.

Another object of the present invention is to provide a method and system for blocking harmful site access and a LAN card therefor that can be selectively blocked according to their purpose in each individual, group, company, and the like.

Another object of the present invention is to provide a method and system for blocking access to harmful sites without requiring a server and an administrator, and a LAN card therefor.

1A to 1C are network configuration diagrams illustrating a conventional harmful site access blocking method.

2 is a block diagram illustrating a method for blocking access to a harmful site according to the present invention.

3 is a schematic block diagram showing an internal configuration of a LAN card having a harmful site access blocking function of the present invention.

4 is a flowchart illustrating a method of blocking a connection to a harmful site by inspecting a transmission packet in an address discriminating unit.

5 is a flowchart illustrating a method of blocking an information from a harmful site by inspecting a received packet in the address discriminating unit.

6 is a schematic block diagram showing the configuration of a harmful site list providing server.

Explanation of symbols on the main parts of the drawings

10 Your computer 20 Local network

21 server 25 telephone network

30Internet Service Providers 35,36 Harmful Site List Database

40 Internet List of 50 Harmful Sites

100 Lancard 200 Harmful Site Listing Database

300 Hazardous Site List Server 400 Hazardous Site List Database

In the present invention, a list of harmful sites and / or healthy sites is provided on the LAN card, and the packets passing through the LAN card are examined to block packets transmitted to the harmful site or packets received from the harmful site. In addition, whether the site is a healthy site or a harmful site for a recently accessed site is stored in the buffer to determine whether the site is a harmful or healthy site. For sites that are not in the healthy site list and the harmful site list provided on the LAN card, the server that provides the harmful / healthy site list update service is inquired about whether the site is harmful or healthy. Until the answer to the query arrives, the packet is queued. In addition, the harmful / healthy site list is periodically downloaded from the harmful / healthy site list providing server, and the harmful site list and / or healthy site list in the LAN card are updated.

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

2 is a block diagram illustrating a method for blocking access to a harmful site according to the present invention.

The LAN card 100 installed in the user's computer 10 is provided with a list 200 of harmful sites and / or healthy sites. Packets from / to the user's computer 10 necessarily pass through the LAN card 100. The LAN card 100 extracts an IP address or URL from the packet passed and compares it with the list 200. Since it is highly likely to be reconnected to a recently accessed site, the list of recently accessed sites may be stored in a separate buffer provided in a LAN card for retrieval speed.

As a result of the search, packets with addresses found to be healthy sites are passed as they are, while packets with addresses found to be harmful sites are discarded.

If the address listed in the packet is a site that is not in the list 200, the LAN card 100 sends a packet to the harmful site list providing server 300 asking whether the site is a harmful site. Until the answer to the query comes from the harmful site list providing server 300, the packet is stored in the queue.

The harmful site list providing server 300 is connected to the harmful site and the healthy site database 400. The harmful site list providing server 300 determines whether the corresponding site is a harmful site according to a query from the LAN card 100, and transmits the result to the LAN card 100.

When the answer from the harmful site list providing server 300 is a harmful site, the LAN card 100 deletes the corresponding packet stored in the queue, and passes the packet stored in the queue in the case of the healthy site.

For example, if a particular website A is a harmful site, even if a user tries to access the site A, the packet is dropped and is not delivered to that site. In addition, even if the user tries to access the harmful site through the link of the healthy site, the packet from the harmful site is blocked in the LAN card 100, so that the user cannot receive information from the harmful site.

Next, an internal configuration of the LAN card 100 according to the present invention will be described with reference to FIG. 3.

In general, the LAN card 100 includes a PCI interface 110 for accessing a PCI bus, which is an internal bus of a computer, a MAC processor 150 for processing a MAC (Media Access Control), and a physical layer for processing a physical layer. A physical layer device (PHY), a buffer for booting a packet, a boot ROM, a connector, and the like are provided.

LAN card 100 of the present invention, in addition to the address discrimination unit 130, the health site list storage unit 141 and / or harmful site list storage unit 142, the transmission packet queue 143, the reception packet queue 144, The server address storage unit 145 is further provided. In addition, a buffer 120 that stores whether a recently accessed site is harmful may be further provided.

In FIG. 3, the address discriminator 130 is located between the PCI interface 110 and the MAC processor 150, but is provided between the MAC processor 150 and the PHY 160 or at the rear of the PHY 160. It is also possible.

The healthy site list storage unit 141 stores the healthy site list provided from the harmful site list providing server 300, and the harmful site list storage unit 142 is a harmful site provided to the harmful site list providing server 300. You are saving a list. The LAN card 100 may include both lists or only one of them.

As the healthy site list storage unit 141 and the harmful site list storage unit 142, a nonvolatile memory such as a flash memory or an EEPROM is used.

The contents stored in the storage units 141 and 142 are numeric values corresponding to IP addresses or character values corresponding to URL addresses. In addition, it is preferable to store by hashing (HASH) without storing the numeric value or the character value as it is. Since the hash algorithm does not have an inverse function, important data contained in the packet cannot be read even if the packet transmitted by the LAN card 100 is intentionally intercepted. In addition, the content stored as a hash value has the advantage that the search time is much faster than the general text search.

The transmission packet queue 143 is a place where packets waiting for a harmful result determination result from the server 300 are temporarily stored among the packets transmitted from the computer 10 to the website A. FIG. Similarly, the reception packet queue 144 is a place in which packets waiting for the harmfulness determination result from the server 300 are temporarily stored among the packets received from the website A. FIG. As the queues 143 and 144, a nonvolatile memory such as a flash memory may be used, or a volatile memory such as a RAM may be used. Existing LAN cards also use queues for buffering when sending and receiving packets.These queues can also be used in common with receive and send packet queues. It may be.

The server address storage unit 145 is formed of a nonvolatile memory such as an EEPROM or a flash memory, and stores an address of the harmful site list providing server 300. The address discrimination unit 130 determines the packet received from the server 300, or transmits a query packet for an address that cannot be identified as a harmful site in the LAN card to the server 300, the server address storage unit 145. Use the address stored in.

The buffer 120 stores whether a recently accessed site is harmful. The number of recently accessed sites stored in the buffer 120 can be arbitrarily determined. If the number of recent access sites stored in the buffer 120 is large, the size of the buffer is increased and the time required for searching the buffer is increased, whereas if the number of recent access sites stored in the buffer 120 is small, the healthy site list storage unit ( 141) or the harmful site list storage unit 142 needs to be searched for, so that the overall speed may be slowed down.

As the buffer 120, a nonvolatile memory such as a flash memory may be used, or a volatile memory such as RAM may be used, but a volatile memory having a high access speed is preferably used.

The address discrimination unit 130 extracts an IP address or URL from the packet passing and compares the address with the addresses stored in the buffer 120 or the list storage units 141 and 142 to determine whether the packet passes. The address discrimination unit 130 may inspect all packets passing through, but first determine whether the packet is a target to be processed, and then process all packets that are not to be processed, and determine whether the packet passes only for the packet to be processed. It is desirable to. Packets to be processed are preferably limited to HTTP (Hyper-Text Transfer Protocol), Telnet, or FTP (File Transfer Protocol) packets, and the determination of whether the packet is to be processed can be known from the packet type and the port number. .

On the other hand, when the address is stored as a hash (HASH) value in the storage unit, the address discriminator 130 determines whether the address matches using the hash value.

Next, the algorithm for determining whether the packet passes through the address discrimination unit 130 will be described in detail with reference to FIGS. 4 and 5. 4 is a flowchart illustrating a method of blocking a connection to a harmful site by inspecting a transmission packet at an address discriminator, and FIG. 5 is a flowchart illustrating a method of blocking information from a harmful site by inspecting a received packet at an address discriminator. to be.

First, referring to FIG. 4, an algorithm for determining whether a packet transmitted from the computer 10 has passed will be described.

As described above, the address discrimination unit 130 may examine all the packets passing through, first determine whether the packet is a processing target packet, and then pass all the packets that are not the processing target and pass the packet only to the packet that is the processing target. You can also decide whether to pass. In the following description, the processing for the packet to be processed is described.

With respect to the packet to be processed, the address discrimination unit 130 pauses the packet transmission of the LAN card and extracts the destination address (IP or URL information) of the packet (S110).

The address discrimination unit 130 stores the paused packet in the packet transmission queue 143 (S120), and compares the destination address extracted from the packet with the address of the latest connection state stored in the buffer 120 ( S130).

As a result of the comparison, if there is a matching address in the buffer 120 and the address is classified as a healthy site (NO in S135), the packet is simply passed (S180). The transmitted packet is deleted from the queue 143.

On the other hand, if there is a matching address in the buffer 120 and the address is classified as a harmful site (YES in S135), the corresponding packet is deleted from the packet transmission queue 143 and the message that the address does not exist. To the computer 10 (S170).

The message of the address which does not exist is sent to a computer by adjusting the HTTP status value. That is, an arbitrary state value is selected from 400 to 499, or 500 to 599. Among the HTTP status values, 400 to 499 correspond to incomplete client requests, and 500 to 599 correspond to status values indicating server errors.

In addition, in the case of TCP / IP, in addition to adjusting the HTTP status value as described above, if TTL (Time To Live) is set to 0, the packet cannot pass through any gateway, so that the user cannot access the harmful site. do.

Instead of sending an error message when attempting to connect to a harmful site, it is also possible to forcibly connect to a healthy site. That is, when the user attempts to access the harmful site, the address discrimination unit 130 changes the address to the address of the healthy site and passes the address. Then, the user attempts to access the harmful site, but since the user is connected to the healthy site, the user can prevent access to the harmful site.

As a result of the determination in step S130, if no address matching the destination of the packet exists in the buffer 120 (NO in S130), the destination of the packet is stored in the buffer 120 as one of the most recent access addresses and the buffer is stored. Delete the oldest address at 120. Then, it is checked whether an address matching the destination of the packet exists in the harmful site list storage unit 142 (S140).

If the address corresponding to the destination of the packet exists in the harmful site list storage unit 142, the process goes to step S170 to delete the packet and sends an addressless message to the computer. Alternatively, as described above, it may be forcibly connected to the healthy site.

If the address corresponding to the destination of the packet does not exist in the harmful site list storage unit 142, it is checked whether the address corresponding to the destination of the packet exists in the healthy site list storage unit 141 (S150).

If the address corresponding to the destination of the packet exists in the healthy site list storage unit 141, the process goes to step S180 to pass the packet as it is.

If the address that matches the destination of the packet does not exist in the healthy site list storage unit 141, the destination address of the packet waiting in the transmission packet queue 143 or the corresponding packet is transmitted to the harmful site list providing server 300. Inquiry whether the site is harmful (S160). The address discrimination unit 130 reads the address of the harmful site list providing server 300 from the server address storage unit 145 and attempts to connect with the server 300.

At this time, since a new connection with the harmful site list providing server 300 is required, the address discrimination unit 130 performs TCP flow control. If the address discrimination unit 130 is not in front of the MAC processing unit 150, a separate block for TCP flow control should be provided in front of the MAC processing unit 150.

When the connection with the harmful site list providing server 300 is established, the address discriminator 130 transmits the address of the target packet to the harmful site list providing server 300. At this time, when the packet address is hashed, the packet is transmitted with the hash value. In this case, the packet transmitted to the server 300 has a structure as shown in Table 1.

IP header TCP Hash Serial Number URL

Since the IP header or TCP are used for general packet transmission, detailed description is omitted. The hash represents the hash value for the extracted IP address or URL. The serial number is a unique serial number of the LAN card (100). The unique serial number is different from the MAC address and is used to distinguish the packet from the computer equipped with the LAN card embodying the present invention in the server 300.

The serial number may consist of a unique number assigned to each LAN card and a serial number assigned to distinguish a packet on its own. When the server 300 sends a response message, by using the serial number as it is, the LAN card 100 can identify which packet the response is. The URL is a target address for querying whether or not it is a harmful site.

Instead of sending the address to query the server 300 whether it is a harmful site, a packet waiting for the transmission packet queue 143 may be sent to the server 300. At this time, in order to send the waiting packet to the server 300, the waiting packet enters the transmission packet queue 143 in the data area of the transmitted packet, and the destination of the packet should be the harmful site list providing server 300.

After the address discrimination unit 130 sends a packet to the harmful site list providing server 300, the address discriminating unit 130 ends the connection with the harmful site list providing server 300 after receiving a response to the query from the harmful site list providing server 300. do. When receiving a response from the harmful site list providing server 300, the address discrimination unit 130 passes or deletes the corresponding packet accordingly. This will be described in detail with reference to FIG. 5.

In addition, if there is no response from the server 300 for a predetermined time after sending the first connection request to the harmful site list providing server 300, for example, 300 seconds, the address discrimination unit 130 sends a second connection request. do. After a second connection request, if there is no response again for a predetermined time, a message indicating that the page does not exist is sent to the computer 10 to delete the packet. Alternatively, the packet may be deleted if a certain time elapses after the first connection request, or the packet may be deleted if a certain time elapses after the third connection request. The present invention is not limited in the number of connection requests. .

Next, an operation when the address discrimination unit 130 receives a packet will be described in detail with reference to FIG. 5.

When receiving the packet, the address discrimination unit 130 stores the packet in the reception packet queue 144 and extracts a source address from the received packet (S210). In addition, the address discrimination unit 130 determines whether the extracted address matches the address stored in the server address storage unit 145 (S220). If the two addresses match, that is, if the received packet is a packet transmitted from the malicious site list providing server 300, it is checked in step S230 whether the packet is a response to the query result.

The packet from the server 300 includes at least a field indicating whether it is a response to the query result or a packet for updating the list, whether or not it is a response to the query, whether it is a harmful site, or a list update.

If the packet from the server is a response to the query result, the address discrimination unit 130 checks whether the address queried by the LAN card 100 is an address of a harmful site if the packet from the server is a response to the query result.

If the address queried by the LAN card 100 is a harmful site, the address discrimination unit 130 sends an addressless message to the user's computer and deletes the packet from the queue 143 or 144 (S242). And, since the address is not listed in the harmful site list storage unit 142, the address discriminating unit 130 stores the address in the harmful site list storage unit 142 (S244). In addition, it records that the address is a harmful site in the buffer 120 having a recent access address.

If the address queried by the LAN card 100 is a healthy site, the address discrimination unit 130 passes the packet as it is and deletes the packet from the queue 143 or 144 (S246). In addition, since the address is not listed in the healthy site list storage unit 141, the address discriminating unit 130 stores the address in the healthy site list storage unit 141 (S248). In addition, it records that the address is a healthy site in the buffer 120 having the latest access address.

As a result of the determination in step S230, if the received packet is not a response to the query result, it is determined whether the packet is list update information (S250). In the case of list update information, the address discrimination unit 130 determines the contents of the packet. As such, the healthy site list storage unit 141 or the harmful site list storage unit 142 is updated (S252).

On the other hand, if it is not a packet transmitted from the server 300 of the received packet, it is determined whether the packet is from a harmful site.

First, in step S260 the address discriminator 130 checks whether the address of the received packet matches the recently connected address stored in the buffer 120.

If there is a matching address, check whether the corresponding address is a harmful site (S261), and if the harmful site deletes the packet from the receiving packet queue 144 and sends an addressless message to the computer (S270). If the address is a healthy site, the packet is passed to the computer 10 as it is (S280).

As a result of checking in step S260, if the address that matches the address of the received packet does not exist in the buffer 120, the address discriminator 130 searches the harmful site list storage unit 142, and the matched address matches the harmful site list. Check whether the storage unit 142 is present (S262). If the address that matches the address of the received packet is in the harmful site list storage unit 142, the process goes to step S270, the packet is deleted from the receiving packet queue 144, and an addressless message is sent to the computer.

If there is no address matching the harmful site list storage unit 142, it is checked whether an address matching the address of the received packet exists in the healthy site list storage unit 141 (S264). If the address that matches the address of the received packet is in the healthy site list storage unit 141, the flow goes to step S280 to pass the packet to the computer 10 as it is.

If the address of the received packet is not present in both the harmful site list storage unit 142 and the healthy site list storage unit 141, the address discrimination unit 130 determines whether the address of the packet is the address of the harmful site. A packet for querying the list providing server 300 is transmitted (S266). Since the procedure at this time has already been described with reference to step S160 of FIG. 4, a detailed description thereof will be omitted.

Next, the configuration and operation of the harmful site list providing server 300 will be described with reference to FIG. 6.

The harmful site list providing server 300 updates a web server 310 for accessing the Internet, a response to a query from the LAN card 100, and a harmful site list and / or a healthy site list in the LAN card 100. LAN card management module 320, DB server 330 that manages the database, such as LAN card DB (370), harmful site DB (350), healthy site DB (360), and while surfing the web periodically A harmful site search engine 340 for updating the site DB 360 and the harmful site DB 350 is included.

When the LAN card management module 320 receives an inquiry about whether a harmful site is a specific address from the LAN card 100, an address corresponding to the harmful site DB 350 or the healthy site DB 360 is transmitted through the DB server 330. If there is a search, the result is sent to the LAN card 100. At this time, by copying the serial number in the packet from the LAN card 100 as it is transmitted to the LAN card 100 so that the LAN card 100 to know which packet to respond.

In addition, from the serial number in the packet received from the LAN card 100 may be to determine whether the LAN card 100 is a legitimate user. That is, when the LAN card 100 is manufactured, a unique number is assigned to each LAN card 100 and stored in the LAN card DB 370. Then, when a query asking for a harmful site from the LAN card 100 comes to check whether a number matching the serial number included in the corresponding query packet exists in the LAN card DB 370, only the query from the LAN card 100 of a legitimate user. It is also possible to respond.

In addition, the LAN card management module 320 generates and transmits a packet for updating the harmful site list and / or the healthy site list in the LAN card 100. The list update packet can be sent regularly, or whenever a socially-issued harmful site appears.

The harmful site search engine 340 updates the harmful site DB 350 and the healthy site DB 360 while surfing the web from time to time or regularly. Since the website is created and destroyed from time to time, it searches for it and continues to update the databases 350 and 360. In addition, in connection with the LAN card management module 320, it is possible to periodically or irregularly transmit the information about the newly created site or expired site to the LAN card (100).

The user can decide what kind of harmful sites his LAN card will block. For example, a typical home may register a securities site as a healthy site, while a company may want to register a securities site as a harmful site. Therefore, the LAN card DB 370 to store the information about the harmful site registered by the user. In addition, the harmful site list stored in the harmful site DB 350 stores information of what type of harmful site, for example, an adult site, a violent site, a chat site, and the like. Then, when the LAN card management module 320 responds whether it is a harmful site according to a query from the LAN card, or when updating the list of harmful sites in the LAN card, the LAN card management module 320 stores the harmful site type stored in the LAN card DB 370. The LAN card management module 320 determines whether or not the harmful site according to the information and the type of the site stored in the harmful site DB (350).

In addition, the LAN card management module 320 is preferably configured to enable or disable the harmful site blocking function of each LAN card (100). That is, a field for activating or deactivating a harmful site blocking function of the LAN card 100 is provided in a packet transmitted to the LAN card 100, and a blocking function activation packet or a blocking function deactivation packet is transmitted to the LAN card 100 as necessary. By activating or deactivating the harmful site blocking function of the LAN card (100).

When the LAN card 100 receives the harmful site blocking function deactivation packet, the LAN card 100 omits the operation of FIG. 4. In addition, in the operation of FIG. 5, only the packet transmitted from the server is checked, and if the packet is transmitted from the server, only the operation of updating the list or activating the harmful site blocking function is performed according to the contents of the packet.

In addition, the user can register to activate the harmful site blocking function only at certain times. Then, the LAN card DB 370 stores data about what time to what time, or from what day to what day to activate the harmful site blocking function in the corresponding LAN card. The LAN card management module 320 transmits a harmful site blocking function activation packet or a harmful site blocking function deactivation packet according to this information stored in the LAN card DB 370, thereby implementing a blocking function by time.

While the present invention has been described with reference to some embodiments, the present invention is not limited thereto. Those skilled in the art will appreciate that many modifications and variations can be made without departing from the spirit of the invention.

According to the present invention, since the access to the harmful site is blocked by installing only the LAN card of the present invention, there is an effect that the access to the harmful site can be blocked irrespective of the reinstallation of the operating system or the system or the system registry.

In addition, since the LAN card itself operates to block harmful sites and does not use computer system resources, there is an effect that it is possible to minimize the Internet speed degradation due to site blocking.

In addition, the blocking site list is stored in the LAN card itself, and the blocking site type for each LAN card can be set in the harmful site list providing server, so that each individual, group, or company can selectively block the block according to their purpose. There is.

In addition, even if a user accesses the Internet using an ADSL modem or a cable modem without a server, the LAN card of the present invention may be installed, so that access to a harmful site can be blocked without a server and an administrator.

Claims (20)

In a method of blocking access to a harmful site from a LAN card having a healthy site list, Storing the packets transmitted or received by the LAN card in a predetermined place and extracting addresses from the packets; Checking whether an address matching the extracted address is stored in the list of healthy sites in the LAN card; If an address matching the extracted address is stored in the list of healthy sites in the LAN card, passing the corresponding packet stored in the predetermined place. Hazardous site access blocking method comprising a. In a method of blocking access to a harmful site from a LAN card having a harmful site list, Storing the packets transmitted or received by the LAN card in a predetermined place and extracting addresses from the packets; Checking whether an address matching the extracted address is stored in the list of harmful sites in the LAN card; If an address matching the extracted address is stored in the list of harmful sites in the LAN card, deleting the corresponding packet stored in the predetermined place and transmitting an addressless message to the computer. Hazardous site access blocking method comprising a. In a method of blocking access to a harmful site from a LAN card having a harmful site list, Storing the packets transmitted or received by the LAN card in a predetermined place and extracting addresses from the packets; Checking whether an address matching the extracted address is stored in the list of harmful sites in the LAN card; If the address that matches the extracted address is stored in the list of harmful sites in the LAN card, changing the destination address of the packet to the address of a preset healthy site and passing the packet through Hazardous site access blocking method comprising a. The method according to claim 2 or 3, The LAN card has a list of healthy sites, Storing the packets transmitted or received by the LAN card in a predetermined place and extracting addresses from the packets; Checking whether an address matching the extracted address is stored in the list of healthy sites in the LAN card; If an address matching the extracted address is stored in the list of healthy sites in the LAN card, passing the corresponding packet stored in the predetermined place. Harmful site access blocking method characterized in that it further comprises. The method of claim 4, wherein Extracting an address from the packet, and then checking whether an address matching the extracted address exists in a buffer that stores the address of a recently accessed site and whether it is a harmful or healthy site, If an address matching the extracted address exists in the buffer and the address is recorded in the buffer as a harmful site, deleting the corresponding packet stored in the predetermined place and transmitting an addressless message to the computer; Passing the corresponding packet stored in the predetermined place when an address matching the extracted address exists in the buffer and the address is recorded in the buffer as a healthy site. Harmful site access blocking method characterized in that it further comprises. The method of claim 4, wherein For an address that is not in both the harmful site list and the healthy site list in the LAN card, sending a packet to the address of the server stored in the LAN card to ask whether the address is a harmful site, Receiving a packet indicating that the address is a harmful site from the server, deleting the packet stored in the predetermined place and transmitting an addressless message to the computer; When a packet indicating that the address is a healthy site is received from the server, passing the packet stored in the predetermined place. Harmful site access blocking method characterized in that it further comprises. The method of claim 6, Storing the address in a list of harmful sites in the LAN card when a packet indicating that the address is a harmful site is received from the server; Storing the address in a list of healthy sites in the LAN card when a packet indicating that the address is a healthy site is received from the server; Harmful site access blocking method characterized in that it further comprises. The method of claim 7, wherein When the packet arrives to disable the harmful site blocking function from the server, thereafter, the LAN card does not perform the harmful site blocking function by passing all the transmitted or received packets except for the packet received from the server. If harmful packet blocking function arrives from the server while the harmful site blocking function is deactivated, then the harmful site blocking function is again performed. Harmful site access blocking method characterized in that it further comprises. The method of claim 6, If the harmful site list update packet is received from the server, updating the harmful site list in the LAN card according to the received packet contents; If a healthy site list update packet is received from the server, updating the healthy site list in the LAN card according to the received packet contents; Harmful site access blocking method characterized in that it further comprises. A harmful site database that stores a list of harmful sites, A healthy site database that stores a list of healthy sites, A database server for managing the databases, If a query for harmful site comes from each LAN card, the LAN card management module sends a response to the corresponding LAN card after searching the harmful site database and the healthy site database through the database server to determine whether the harmful site exists. And a list of harmful sites provided with a server, A server address storage unit storing the address of the harmful site list providing server, A transmission packet queue that temporarily stores the transmission packet, A received packet queue that temporarily stores a received packet, A harmful site list storage unit that stores an address of a harmful site, A healthy site list storage unit that stores the address of the healthy site, By extracting the address from the packet transmitted and received, it is determined whether the harmful site by referring to the harmful site list storage unit and the healthy site list storage unit, and for the addresses that are not both the harmful site list storage unit and the healthy site list storage unit Harmful Site List Provides a query to the server for harmful sites to determine whether they are harmful, and if it is a harmful site, deletes the packet, and if it is a healthy site, an address discrimination unit that passes the packet. LAN card with Hazardous site access blocking system consisting of. The method of claim 10, The harmful site list providing server further includes a LAN card database that stores identification information of each LAN card and information on the type of a site to be determined as a harmful site for each LAN card. The harmful site database stores the harmful site address and the type of the harmful site. The LAN card management module is harmful site access blocking system, characterized in that for updating the harmful site list storage unit of each LAN card according to the information on the type of harmful site or in response to the query for harmful sites from each LAN card. The method of claim 11, The LAN card database further includes information on the time zone for activating the harmful site access blocking function for each LAN card, The LAN card management module transmits a harmful site access blocking function activation or deactivation packet to each LAN card according to the information on the time zone of the LAN card database. The address discrimination unit omits the operation of determining the harmful site by extracting the address of the packet when the harmful site access blocking function deactivation packet is received, and extracts the address of the packet when receiving the harmful site access blocking function activation packet. Harmful site access blocking system, characterized in that to resume the operation of determining. The method of claim 11, The LAN card management module transmits a harmful site determination result packet only when a LAN packet identification number included in the query packet matches a LAN card identification number stored in the LAN card database when a query packet regarding a harmful site comes from a LAN card. Hazardous site access blocking system. The method of claim 10, The LAN card further includes a buffer that stores the address of the recently accessed site and whether the address is harmful site, Before referring to the harmful site list storage unit and the healthy site list storage unit, the address discriminating unit checks whether an address corresponding to an address extracted from the packet exists in the buffer and matches the extracted address. If the address is present in the buffer, the harmful site is blocked according to the information on whether the harmful site is stored in the buffer, the packet is deleted if the harmful site, and if the healthy site access packet blocking system, characterized in that passing through the packet . A LAN card comprising a PCI interface for interfacing with a PC, a MAC processing unit for processing a MAC of a packet, and a physical layer interface for connecting to an Internet network, Server address storage unit that stores the address of the harmful site list providing server, A transmission packet queue that temporarily stores the transmission packet, A received packet queue that temporarily stores a received packet, A harmful site list storage unit that stores an address of a harmful site, A healthy site list storage unit that stores the address of the healthy site, By extracting the address from the packet transmitted and received, it is determined whether the harmful site by referring to the harmful site list storage unit and the healthy site list storage unit, and for the addresses that are not both the harmful site list storage unit and the healthy site list storage unit, It reads the address of the harmful site list providing server from the server address storage unit and transmits a packet querying the harmful site list providing server to check whether the harmful site exists. The address discrimination unit determines whether or not a site, and deletes the packet in case of harmful site and passes the packet in case of health LAN card having a. The method of claim 15, It further includes a buffer that stores the address of the recently accessed site and whether the address is harmful, Before referring to the harmful site list storage unit and the healthy site list storage unit, the address discriminating unit checks whether an address corresponding to an address extracted from the packet exists in the buffer and matches the extracted address. And if the address is present in the buffer, delete the packet in the case of a harmful site according to the information on whether the harmful site is stored in the buffer, and pass the packet in the case of a healthy site. The method of claim 15, The address discriminating unit is a LAN card, characterized in that for the packet to the site that is found to be a harmful site change the address to a predetermined health site address and pass the packet. The method of claim 15, And the information stored in the harmful site list storage unit and the healthy site list storage unit is stored in an encrypted form using a hash function. The method of claim 15, And the address discriminating unit is located between the PCI interface and the MAC processing unit. The method of claim 15, The address discriminator LAN card, characterized in that if the response to the harmful site from the harmful site list providing server reaches a harmful site list storage unit or harmful site list storage according to whether the harmful site.