KR20100092768A - Method for providing mac protocol for data communication security in wireless network communication - Google Patents

Abstract

The present invention provides a method for providing a MAC protocol for data communication security in a wireless network communication system, comprising: an encrypted key seed for encryption and a time stamp for time synchronization at a data transmitting node Generating and transmitting a request to send (RTS) message data frame including the value in a data field area to a data receiving node; and receiving the time stamp and key at the data receiving node receiving the RTS message data frame. After demodulating the seed value, a time stamp and a key seed value are generated based on the seed value and included in the data field area of the clear to send message data frame and transmitted to the node that sent the RTS message data frame. And a time stamp received at the data transmitting node receiving the CTS message data frame. It is characterized in that it comprises the process of performing the change to the corresponding channel and the duration by the value.

Description

METHOD FOR PROVIDING MAC PROTOCOL FOR DATA COMMUNICATION SECURITY IN WIRELESS NETWORK COMMUNICATION}

 The present invention relates to a method for providing a Mac protocol for data communication security in a wireless network communication system. In particular, an encryption algorithm for securing data communication in a Mac protocol in a process of initializing communication of data transmission / reception nodes is provided. It is applied to the channel negotiation and channel time slot of the frequency hopping method to reduce the data transmission security at the physical layer of the transmitting / receiving node and to secure data communication in the wireless network communication system. The present invention relates to a Mac protocol providing method.

Due to the diversification of communication environments such as mobile networks and home networks, the stability of information security between communication devices is one of important concerns. Such IP-based communication environment has been developed to improve user convenience, but at the same time has a problem that information security is vulnerable due to easy access by third parties.

To solve this problem, various types of encryption algorithms exist in the data communication service provided by the wireless network communication system.

In a wireless network, the encryption algorithm is applied for encrypted communication, and the entire data is encrypted by software or hardware, and data messages are transmitted and received. In addition to being able to drop, network encryption devices incur inefficient power consumption due to complex encryption algorithms for processing the encrypted message.

In addition, encryption media access control (MAC) protocols currently used in wireless network communication encrypt and process all data during channel negotiation and channel duration, that is, time slot allocation, and to maintain the encryption state. It has a security vulnerability that can be attacked in the process of distributing cryptographic keys.

In the encrypted MAC protocol, the management of encryption keys is very important. For example, centralized key generation is a method of assigning individual keys to a plurality of nodes that form a network in which a key distribution server exists. Because it is encrypted with hardware, if there is a problem with the key distribution server, the entire network is affected, and the node forming the network is applied to a self-organized network in which the network nodes arbitrarily repeat joining or leaving the network. This is difficult. Here, the autonomous-subscribing network is represented by an Ad-Hoc network and a mesh network.

In addition, the distributed group key generation method not only increases the complexity of the calculation but also exposes the key to a third party because when the new node joins the network, not only the new node participating but also all nodes forming the network must update the key at the same time. Vulnerability is in the process of being distributed to crypto communication partners.

As described above, the problems of encryption technologies based on key management assume that the communication process before the formation of a wireless network is secure, and focus only on encryption and encryption key management. Inefficient power consumption occurs in terms of communication efficiency and speed of wireless networks.

An object of the present invention is to provide a MAC protocol for data communication security in a wireless network communication system. In particular, 1: 1 key distribution, authentication and time slots between nodes for encrypted communication in communication initialization of data transmission / reception nodes are provided. In addition, by blocking the possibility of attack inherently, data communication is applied to the Mac protocol by applying an encryption algorithm for the security of data communication to the frequency hopping channel negotiation and channel time slot. The present invention relates to a method for providing a MAC protocol for data communication security in a wireless network communication system that reduces the eavesdropping probability in the physical layer of a transmitting / receiving node and denies eavesdropping.

According to an aspect of the present invention to achieve the above object, in a method for providing a MAC protocol for data communication security in a wireless network communication system, a time stamp for time synchronization (sync) and at the data transmitting node and Generating a request to send (RTS) message data frame by generating an encrypted key seed value for encryption and including the same in a data field area, and transmitting the request to send (RTS) message data frame to the data receiving node; After demodulating the time stamp and key seed values at the receiving node, the time stamp and key seed values are generated based on this, and are included in the data field area of the clear to send message data frame. Transmitting the RTS message data frame to the transmitting node, and transmitting the CTS message data frame. And performing a change to the corresponding channel and a duration according to the received time stamp value at the received data transmitting node.

As described above, the present invention enables 1: 1 time synchronization between data transmitting / receiving nodes that does not burden the entire network by channel division according to time in a wireless network communication system, thereby effectively using communication frequency and data. In addition to reducing the transmission failure, since the address of each node is not used due to the 1: 1 time synchronization, there is an effect of preventing the possibility of being attacked from the outside.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, specific matters such as specific elements are shown, which are provided to help a more general understanding of the present invention. It is self-evident to those of ordinary knowledge in Esau.

First, the present invention is to perform secure data communication in a wireless network using a carrier sense multiple access / collision detect (CSMA / CD) protocol based on the IEEE 802.3 standard. Applicable to negotiation and time slots, it is noted that the network communication is related to the reduction of the eavesdropping probability at the physical PHY level and the rejection of the eavesdropping.

In addition, in the practice of the present invention, all nodes in the wireless network communication have pre-distributed pre-shared keys capable of decrypting key authentication and key-seed for data security. On the premise.

Hereinafter, a structure of a data frame transmitted / received in a wireless network according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

First, FIG. 1 illustrates a general structure of a data frame 100 transmitted during data communication in a wireless network communication system based on an encryption algorithm of a MAC protocol according to an embodiment of the present invention.

Referring to FIG. 1, first, the data frame 100 includes a preamble (110) field for providing frame arrival notification information to a receiver, and a message type (message type) 112 for specifying a type of data. Field, a source address (114) field indicating the physical address of the source, a destination address (116) field indicating the physical address of the destination, and a data length (118) indicating the length of the data. Field, a data field 120 for data received from a higher layer, and a cyclic redundancy check field 122 for error detection.

Subsequently, FIG. 2 illustrates a structure of a data frame for each transmission / reception node during data communication in a wireless network communication system based on an encryption algorithm of a MAC protocol according to an embodiment of the present invention.

Referring to FIG. 2, first, 200 is a request to send (RTS) message data frame, and the RTS message data frame 200 is generated at a transmitting node to which data is to be transmitted.

In the data frame 100 shown in FIG. 1, the RTS message data frame 200 sets a message type field that specifies the type of data to RTS, and the data fields 206 for data each perform time synchronization. A time stamp (202) field and a key seed (204) value field field.

The time stamp 202 field is an area for time synchronization between nodes for data transmission / reception.

That is, an area for matching the time relationship in the time domain rather than the frequency domain between two space and time data transmitting / receiving nodes, which is an exact match with the current time (hour / minute / second). In this case, time synchronization means one-to-one time synchronization between communicating nodes, not absolute synchronization over the entire network.

The key seed value field field is an area for a key seed value generated by encrypting for communication security during data transmission / reception.

Here, various existing encryption algorithms may be applied to encrypt the key seed value, and the present invention will be described by ciphering Francis Bacon as an example.

Francis Bacon's cryptography uses an uppercase letter of the English alphabet as 0 and a lowercase letter as 1. For example, if the key seed value is 0x06 in hexadecimal, 0b0000 0101 in binary. The value may be symmetrical to the SAFE SaFe, since SAFE is all uppercase 0000, SaFe may be represented as 0101 because the uppercase, lowercase, uppercase, lowercase.

Subsequently, 210 is a clear to send message data frame, and the CTS message data frame 210 is generated at a receiving node that receives data from a transmitting node.

The CTS message data frame 210, in the data frame 100 shown in FIG. 1, sets a message type field that specifies the type of data to CTS, and the data fields 208 for data each perform time synchronization. A time stamp field 212 and a key seed value field field.

The time stamp 212 field is an area for time synchronization between nodes for data transmission / reception. In this case, time synchronization means one-to-one time synchronization between communicating nodes, not absolute synchronization over the entire network.

The key seed (214) value field is a field for a key seed value generated by encrypting for communication security during data transmission / reception, and various existing encryption algorithms can be applied. In the present invention, Francis Bacon Will be described using the cipher method as an example.

Next, 220 is a Tx complete message data frame, and the Tx complete message data frame 220 is for notification of completion of data transmission.

In the data frame 100 shown in FIG. 1, a message type field specifying a type of data is set to a Tx complete message, and data is not included and is generated when data transmission is completed at each transmitting and receiving node.

FIG. 3 is an exemplary view schematically illustrating frequency hopping (FH) for each node on a wireless channel in data communication between transmitting and receiving nodes in a wireless network according to an embodiment of the present invention.

Here, the frequency hopping is a frequency hopping, i.e., a spreading band scheme in which the center frequency of the transmission signal continues to move within a specific frequency band. Means move.

Referring to FIG. 3, a node trying to transmit or receive data uses a common channel 310 to request RTS message data frames B, C, and E, and CTS message data frames A and D, respectively. , F) is transmitted to the node to be transmitted. Data transmitting / receiving nodes attempting to transmit on the common channel 310 indicate communication initialization over time, using a time set in a time stamp area of each RTS or CTS message data frame. Will communicate. Therefore, each data transmission / reception node occupying a certain area in each of the divided plurality of channels 312, 314, and 316 illustrated in FIG. 3 means an occupation for a specific time on the corresponding channel. This means that a plurality of channels are divided and used over time. For example, after the nodes ie A and C to communicate using the common channel 310 receive the RTS and CTS message data frames for data transmission / reception, respectively, the nodes of the other party are referred to. Based on the time set in the time stamp area of each RTS and CTS message data frame received via node A, the node A occupies a specific time of channel 2 314 and channel 3 316, and node C occupies channel 1 312. And occupy a specific time of channel 3 316.

A detailed description of the channel allocation method according to the present invention and a Mac protocol method for data communication security in a wireless network communication system according to an embodiment of the present invention will be described in detail with reference to FIGS. 4 and 5.

4 is a flowchart illustrating an operation process of a data transmitting node in a method of providing a MAC protocol for data communication security in a wireless network communication system according to an embodiment of the present invention.

Referring to FIG. 4, first, communication initialization for data communication is performed in step 410, that is, each node to communicate with is in a standby state. The RTS message data frame is generated using a common channel for channel negotiation for communication. In this case, the RTS message data frame sets a message type field that specifies the type of data to RTS, and the data field for data includes a time stamp area and a key seed value area field.

The time stamp region is an area for time synchronization between nodes for data transmission / reception, and is an area for time relationship matching in a time domain, not a frequency domain, between two space and data transmission / reception nodes having different time. , Exact match for current time (hours / minutes / seconds). Accordingly, the data transmitting node designates the time to be used by the data transmitting node and records the time in the time stamp field.

Here, time synchronization according to an embodiment of the present invention means one-to-one time synchronization between communicating nodes, not absolute synchronization over the entire network.

The key seed value field field is an area for a key seed value generated by encrypting for communication security during data transmission / reception.

When encrypting the key seed value, Francis Bacon's encryption method is used, and the key seed value encrypted by the algorithm is modulated for transmission.

The RTS message data frame generated in step 412 is transmitted to a receiving node to communicate with it (step 414).

In step 416, after confirming reception of the CTS message data frame from the node transmitting the RTS message data frame in step 414, the process proceeds to step 422.

In the CTS message data frame, the message type field is set to CTS. The data field is the same as the data field of the RTS message data frame including a time stamp area for time synchronization between nodes and a key seed value area field generated by encrypting for security.

If the CTS data frame is not received from the node that transmitted the data frame, the flow proceeds to step 420. When the RTS message is generated in step 412 in the reception standby state, the set time is checked to continuously receive the CTS message data frame from the counterpart node within the set time. If the set time has elapsed in this process, the process jumps to step 412 and the node to transmit data regenerates an RTS message data frame using a common channel for channel negotiation for data communication with the data receiving node to communicate with. do.

Meanwhile, in step 422 after receiving the CTS message data frame, the data transmitting node negotiates a channel by using a key seed value and a time stamp information value included in the received CTS message data frame for data communication with the receiving node. And search for information of channel duration.

In step 424, the data transmission node starts a channel change and channel duration timer using the key seed value and the time stamp information value.

In step 424, the channel is changed, and carrier sensing of the corresponding channel is performed to confirm the frequency of use of the channel to be changed, that is, whether other nodes are used. As a result of the check, if the channel is in use by another node at the time corresponding to the channel time that the data transmitting node wants to use, that is, the time stamp information value included in the received CTS message data frame, the change to another channel and other Jump to the previous step 412 for channel occupancy on channel time, ie, return to the common channel, regenerate the RTS message data frame, and repeat the steps below 412.

If the corresponding channel is empty at the time that the data transmitting node wants to use, the time specified in step 412 is assigned to the time stamp information value included in the CTS message data frame by the channel information obtained by the process in step 422. The timer is set by adding the stamp value to determine the final channel duration (step 427).

In step 428, within the determined final channel duration, the data transmitting node transmits data to a receiving node with which it wants to communicate, and when all data to be transmitted are completed, the data transmitting node sends a Tx complete message to the receiving node. By transmitting a notification of the completion of data transmission between the transmitting and receiving nodes (430).

The Tx complete message sets a message type field indicating a type of data in a Mac data frame as a Tx complete message and does not include data, and is generated when data transmission is completed at each transmitting and receiving node.

5 is a flowchart illustrating an operation process of a data receiving node in a Mac protocol providing method for data communication security in a wireless network communication system according to an exemplary embodiment of the present invention.

Referring to FIG. 5, first, communication initialization is performed for data communication in step 510, that is, nodes to be communicated through the standby state, and in step 512, whether the RTS data message frame is received from a predetermined node in the wireless network is checked. do.

In this case, the RTS message data frame sets a message type field that specifies the type of data to RTS, and the data field for data includes a time stamp area and a key seed value area field. When it is received, demodulating the time stamp region included in the modulated RTS message data frame and the value of the key seed value region field to obtain channel and duration information to which the data transmitting node communicates (step 514).

In operation 516, the time stamp value of the RTS message data frame received from the data transmitting node is compared with its own time stamp value, thereby correcting time synchronization, that is, an error with the received time stamp value. In this case, time synchronization means one-to-one time synchronization between communicating nodes, not absolute synchronization over the entire network.

In step 518, the data receiving node encrypts the CTS message data frame by encrypting the corrected time stamp value and the key seed value. The modulated CTS message data frame is transmitted to the node that transmitted the RTS message data frame (step 520).

In step 522, the data receiving node changes its channel according to the channel information included in the received RTS message data frame and the time stamp value corrected in step 516, and then starts its own timer.

After the timer is started, after checking whether the data is received from the data transmitting node (step 524), if no data is received, continuously checking whether the timer is operated (step 526), and checking whether the data is received within the set time. Keep checking.

At this time, when the set time is over, the data receiving node transmits a TX complete message to the receiving node to notify completion of data transmission between the transmitting and receiving nodes (step 528).

When data is received from the data transmission node, the received data is processed (step 530), and communication with the data transmission node is terminated.

As described above, an operation related to a Mac protocol providing method for security of data communication in a wireless network communication system according to an embodiment of the present invention may be performed. Meanwhile, in the above description of the present invention, specific embodiments have been described. Branch modifications may be made without departing from the scope of the present invention.

Accordingly, the scope of the present invention should not be limited by the illustrated embodiments, but should be determined by equivalents of the claims and the claims.

1 is a structural diagram showing a general structure of a data frame transmitted during data communication in a wireless network communication system based on an encryption algorithm of the MAC protocol according to an embodiment of the present invention.

2 is a structural diagram of a data frame for each transmitting / receiving node during data communication in a wireless network communication system based on an encryption algorithm of a MAC protocol according to an embodiment of the present invention.

FIG. 3 is an exemplary view illustrating frequency hopping (FH) for each node on a wireless channel during data communication between transmitting and receiving nodes in a wireless network according to an embodiment of the present invention.

4 is a flowchart illustrating an operation process of a data transmitting node in a Mac protocol providing method for data communication security in a wireless network communication system according to an embodiment of the present invention.

5 is a flowchart illustrating an operation process of a data receiving node in a Mac protocol providing method for data communication security in a wireless network communication system according to an embodiment of the present invention.

Claims (14)

In the Mac protocol providing method for data communication security in a wireless network communication system, Request to send (RTS) message data that generates a time stamp for time synchronization and an encrypted key seed value for encryption at the data sending node and includes it in the data field area. Generating a frame and transmitting the frame to a data receiving node; A data field of a CTS (clear to send) message data frame is generated by demodulating a time stamp and key seed value at the data receiving node receiving the RTS message data frame, and generating the time stamp and key seed value based on the demodulated time stamp and key seed value. Transmitting the RTS message data frame to a node including the data in a region; And a process for changing to a corresponding channel and performing a channel duration by a time stamp value received at the data transmitting node receiving the CTS message data frame. How to provide a protocol. The method of claim 1, The data transmitting node may further include starting an operation of its own timer according to a set time stamp value when generating an RTS message data frame. How to provide a protocol. The method of claim 1, The data transmitting node may further include continuously checking a timeout of its own timer in operation when the CTS message data frame is not received from the node transmitting the RTS message data frame. How to provide Mac protocol for data communication security in system. The method of claim 1, In either node of data transmission or reception, if the message type field specifying the data type is set to a Tx complete message and a Tx complete message data frame including no data is received, the process of completing the entire data communication is completed. Mac protocol method for data communication security in a wireless network communication system, further comprising. The method of claim 1, wherein the transmission of the RTS and CTS message data frames is performed on a common channel in a wireless network. 2. The MAC of claim 1, wherein the time stamp values of the RTS and CTS message data frames are one-to-one time synchronization between nodes transmitting / receiving data. How to provide a protocol. The method of claim 1, In the wireless network communication system, the data transmitting node further includes a step of checking whether the corresponding channel time is used by another node after carrier sensing of a channel corresponding to a channel time to be changed. How to provide Mac protocol for data communication security. The method of claim 1, If the corresponding channel to be changed by the data transmission node is in use by another node, the method returns to the common channel and regenerates an RTS message data frame. . The method of claim 1, The time stamp value for the CTS message data frame of the data receiving node is set after correcting the error by comparing with the time stamp value of the received RTS message data frame. How to provide one Mac protocol. The method of claim 1, The data receiving node changes the time stamp values of the RTS and CTS message data frames to the corresponding channel time through comparison and error correction, and starts its own timer at the set time. How to provide Mac protocol for Windows. The method of claim 10, And the data receiving node continuously checks whether or not data is received for a predetermined time from the data transmitting node after the timer is started. The method of claim 1, The key seed value is generated by applying to an encryption algorithm, the MAC protocol providing method for communication security in a wireless network communication system. The wireless network communication according to claim 1, wherein the data transmitting / receiving node communicates data in a wireless network using a carrier sense multiple access / collation detect (CSMA / CD) protocol based on the IEEE 802.3 standard. How to provide Mac protocol for communication security in new system. The method according to any one of claims 1 to 12, wherein the plurality of channels are divided according to time.

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