KR102038473B1 - Group communication method and system - Google Patents

Abstract

The present invention relates to a group communication method where nodes that can participate in a group have a common red-black (RB) tree construction algorithm. According to the present invention, the group communication method comprises the steps of: sharing a member list including identification information of nodes by nodes wishing to form a group; configuring, by each of the nodes, an RB tree using an RB tree construction algorithm based on the identification information of the member list, and identifying a node connected to the node on the RB tree; and establishing a security session with a node to which each of the nodes is connected.

Description

Group communication method and system

The present invention relates to a group communication method and system, and more particularly, to a group communication method and system in which group members can establish a group communication environment without a centralized device.

With the recent increase in Internet speed and connectivity, group communication environments such as group chat, video conferencing, online collaborative workspaces, multi-user games, etc. have exploded.

The existing group communication environment mainly uses a server-client model, in which multiple users connect to a common server and exchange information with each other through a server. However, this server-client based group communication environment is more vulnerable to security than one-to-one communication environment, and service providers open the platform and APIs to expand their services, which makes it easier for attackers to analyze vulnerability. Exposure and attack threats are increasing.

In order to enhance security in the group communication environment, there is a communication method in which group members share a group key and encrypt / decrypt data with the group key, but this also requires a centralized device that manages the group key. It takes a long time to share or update the network, which is inefficient.

The technical problem to be achieved by the present invention is to provide a group communication method and system that allows group members to build a group communication environment without a centralized device and to efficiently perform group communication by reducing the number of secure sessions established between group members. There is.

The problem to be solved of the present invention is not limited to the above-mentioned problem, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

In the group communication method according to the present invention for solving the technical problem, the nodes that can participate in the group has a common Red-Black (RB) tree configuration algorithm, the group communication method, Sharing the member list including the identification information of the nodes; Identifying, by the nodes, an RB tree using the RB tree construction algorithm based on the identification information of the member list, and a node connected to the node on the RB tree; And establishing a secure session with each node connected to the nodes.

In the sharing of the member list, one of the nodes may share the member list by transmitting the member list to other nodes.

The group communication method may include: transmitting a message through a secure session to a node connected to the node to which the node to transmit the message is connected; And the node receiving the message further transmits the message to a node connected to the node other than the node that has sent the message through a secure session, so that the message can be delivered to all of the nodes. .

The group communication method may further include: when there is a node to additionally join the group, any one of the nodes sends a join request message of the node to a node connected with the node through a secure session; The node receiving the participation request message further includes transmitting the participation request message through a secure session to a node connected to the node other than the node that sent the participation request message to the node. The request message can be delivered.

In the group communication method, a new RB tree is formed using the RB tree construction algorithm based on the identification information of the member list, wherein the nodes and the node to join each further include identification information of the node to join. Identifying a node associated with itself on the new RB tree; And each of the nodes and the node to participate in establishes a secure session with a node newly connected to the node or maintains a secure session with a previously connected node according to a node connected with itself on the new RB tree. The method may further include terminating the session.

The group communication method may further include transmitting, by a node intending to leave the group, a withdrawal request message to a node connected to the node through a secure session; The node receiving the withdrawal request message further includes transmitting the withdrawal request message to a node connected to itself other than the node that sent the withdrawal request message through a secure session, thereby transmitting the withdrawal request to all of the nodes. The request message can be delivered.

In the group communication method, each node receiving the withdrawal request message constructs a new RB tree using the RB tree construction algorithm based on the identification information of the member list except for the identification information of the node to withdraw. Identifying nodes associated with themselves on the RB tree; And each node receiving the withdrawal request message establishes a secure session with a node newly connected to each other, maintains a secure session with a node already connected, or a secure session with a node previously connected according to a node connected with the node on the new RB tree. It may further comprise the step of ending.

The secure session can be established using public key based encryption.

The group communication system according to the present invention for solving the above technical problem, includes nodes having a common RB tree configuration algorithm as nodes that can participate in the group, the nodes to configure the group to identify the identification information of the nodes Share a member list, wherein the nodes each form an RB tree using the RB tree construction algorithm based on the identification information of the member list, and identify nodes connected to themselves on the RB tree; It is characterized by establishing a secure session with the node connected to it.

In order for the nodes to share the member list, one of the nodes may send the member list to other nodes.

Among the nodes, a node that wants to transmit a message transmits a message through a secure session to a node connected to the node, and a node receiving the message transmits a message through a secure session to a node connected to itself other than a node that has sent a message to the node. The message can be delivered to all of the nodes by sending the message.

If there is a node to further participate in the group, one of the nodes sends a participation request message of the node to a node connected to the node through a secure session, and the node that receives the participation request message The participation request message may be delivered to all of the nodes by transmitting the participation request message to a node connected to the node other than the node that sent the participation request message to the node through a secure session.

The nodes and the node to join each form a new RB tree using the RB tree construction algorithm based on the identification information of the member list further including identification information of the node to join, and on the new RB tree. Identify the node connected to the node, and the nodes and the node to join each establish a secure session with the node newly connected to each other or maintain a secure session with the node connected to the node according to the node connected with the node on the new RB tree. Or terminate a secure session with a previously connected node.

A node intending to leave the group transmits a withdrawal request message to a node connected to the node through a secure session, and the node receiving the withdrawal request message is secured to a node connected to itself other than the node that sent the withdrawal request message to the node. The withdrawal request message may be delivered to all of the nodes by sending the withdrawal request message through a session.

Each node receiving the withdrawal request message forms a new RB tree using the RB tree construction algorithm based on the identification information of the member list except for the identification information of the node to withdraw, and is connected with itself on the new RB tree. Nodes that have checked the node and received the withdrawal request message each establish a secure session with, or maintain a secure session with, a newly connected node according to their associated node on the new RB tree. You can terminate the secure session with.

The secure session can be established using public key based encryption.

In the group communication method according to the present invention for solving the technical problem, the nodes that can participate in the group has a common RB tree configuration algorithm, the group communication method, the nodes to configure the group of nodes Sharing a member list including identification information; Identifying, by the nodes, an RB tree using the RB tree construction algorithm based on the identification information of the member list, and a node connected to the node on the RB tree; Establishing, by the nodes, a secure session using public key based encryption with a node connected to each of the nodes; Transmitting a message through a secure session to a node connected to the node to which a message to be transmitted is transmitted; The node receiving the message transmits the message through a secure session to a node connected to itself other than the node that has sent the message to the node, thereby delivering the message to all of the nodes; If there is a node to further participate in the group, any one of the nodes sends a join request message of the node to a node connected to the node through a secure session; The node receiving the participation request message transmits the participation request message to a node connected to itself other than the node that sent the participation request message through a secure session, whereby the participation request message is transmitted to all the nodes. step; The nodes and the node to join each form a new RB tree using the RB tree construction algorithm based on the identification information of the member list further including identification information of the node to join, and on the new RB tree. Identifying a node associated with itself; And each of the nodes and the node to participate in establishes a secure session with a node newly connected to the node or maintains a secure session with a previously connected node according to a node connected with itself on the new RB tree. Terminating the session.

In the group communication method according to the present invention for solving the technical problem, the nodes that can participate in the group has a common RB tree configuration algorithm, the group communication method, the nodes to configure the group of nodes Sharing a member list including identification information; Identifying, by the nodes, an RB tree using the RB tree construction algorithm based on the identification information of the member list, and a node connected to the node on the RB tree; Establishing, by the nodes, a secure session using public key based encryption with a node connected to each of the nodes; Transmitting a message through a secure session to a node connected to the node to which a message to be transmitted is transmitted; The node receiving the message transmits the message through a secure session to a node connected to itself other than the node that has sent the message to the node, thereby delivering the message to all of the nodes; Transmitting, by a node intending to leave the group, a leave request message to a node connected to the node through a secure session; The node receiving the withdrawal request message transmits the withdrawal request message to a node connected with itself other than the node that has sent the withdrawal request message to the node through a secure session, thereby transmitting the withdrawal request message to all the nodes. step; Nodes receiving the withdrawal request message each form a new RB tree using the RB tree construction algorithm based on the identification information of the member list excluding the identification information of the node to withdraw, and are connected to themselves on the new RB tree. Identifying a node; And each node receiving the withdrawal request message establishes a secure session with a node newly connected to each other, maintains a secure session with a node already connected, or a secure session with a node previously connected according to a node connected with the node on the new RB tree. It characterized in that it comprises the step of ending.

According to the present invention described above, there is an advantage that group members can establish a group communication environment without a centralized device and can efficiently perform group communication by reducing the number of secure sessions established between group members.

The effects of the present invention are not limited to the above-mentioned effects, and other effects that are not mentioned will be clearly understood by those skilled in the art from the following description.

1 shows an example of an RB tree.
2 is a flowchart illustrating a process of configuring a group communication network according to an embodiment of the present invention.
3 shows an example of nodes that will constitute a group communication network.
4 shows an example of how an RB tree is constructed from a member list.
5 is a flowchart illustrating a process of transmitting a message from one node to other nodes in a group communication network configured by using an RB tree.
FIG. 6 shows an example in which a message from one node is delivered to all nodes in the group communication network configured through FIG. 4.
7 is a flowchart illustrating a process of reconfiguring a group communication network by joining a new node to an already configured group communication network.
8 shows an example in which a join request message is delivered to all nodes in a group communication network.
9 shows an example of constructing a new RB tree from a new member list with a node added.
FIG. 10 shows an example in which a message from one node is delivered to all nodes in the group communication network configured through FIG. 9.
11 is a flowchart illustrating a process of reconfiguring a group communication network by withdrawing one node from a group communication network.
FIG. 12 shows an example of the withdrawal request message being delivered to all nodes in the group communication network of FIG. 10.
13 shows an example of a new RB tree being constructed from a new member list in which a node is deleted.
FIG. 14 shows a newly configured group communication network through FIG. 13.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description and the accompanying drawings, the substantially identical components are represented by the same reference numerals, and thus redundant description will be omitted. In addition, in the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

The group communication method and system according to an embodiment of the present invention constitute a group communication network using a red-black (RB) tree. First, the RB tree will be briefly described.

1 shows an example of an RB tree. The RB tree is a self-balancing binary search tree, typically a data structure used to implement associative arrays. When there are n elements in the tree, you can insert, delete, and search with O (log n) time complexity.

RB trees are a special form of binary trees that are used in computer engineering to organize comparable data such as numbers. In a binary tree, each piece of data is stored in a node. When storing data in a tree structure, the node at the top of the nodes is called the root node. In a binary tree, a node can have up to two child nodes associated with it. Each child node can also have up to two child nodes associated with it, and so on. Therefore, any tree can reach all nodes belonging to that tree from the root node of that tree.

If a node does not have child nodes, it is called a leaf node because it is at the very edge of the tree. One of the nodes of the tree is the root node, and the tree composed of itself and its child nodes has the same tree structure, which is called a sub-tree. In RB trees, leaf nodes are empty and contain no data.

The RB tree has the condition that for every node, 'the data that you have is less than or equal to all of the data that the subtree located to the right of you is greater than or equal to all of the data of the subtree located to the left of you'. Satisfies. Because of these characteristics, specific values can be found quickly, and efficient in-order traversal between elements is possible.

The RB tree is a binary search tree with color attributes where each node is red or black. The general condition of the binary search tree must satisfy the following additional conditions to be a valid RB tree.

1. A node is either red or black.

2. The root node is black.

3. All leaf nodes are black.

4. Both child nodes of a red node are always black. (I.e. red nodes cannot appear in succession, only black nodes can be parent nodes of red nodes)

5. Every path starting from a node to a leaf node has the same number of black nodes except the leaf node.

If the above conditions are met, the RB tree exhibits important characteristics. The distance from the root node to the farthest path is always less than twice the distance to the nearest path. In other words, the RB tree is roughly balanced. Therefore, it is more efficient than the ordinary binary search tree because the time complexity in the worst-case of insertion, deletion and search is determined by the height (or depth) of the tree.

When representing a tree structure, some nodes may have only one child, and leaf nodes may contain data. The RB tree can also be represented in this manner, but such representation may change the characteristics of the RB tree and may conflict with the algorithm. Thus, in the example of FIG. 1, "nil leaves" or "null leaves" are used. The "null leaf" does not have data as in FIG. 1 and is used only to indicate the end of the tree. When expressing a tree structure, it is often omitted to draw this "null leaf" ("null leaf" is also omitted in the RB tree of other drawings in this specification), then the characteristics of the red-black tree graphically It may seem unsatisfactory, but in reality it is not. By doing so, all nodes will have two children, even if one or two children are "null leaf".

2 is a flowchart illustrating a process of configuring a group communication network according to an embodiment of the present invention. FIG. 3 shows an example of nodes that will constitute a group communication network, and FIG. 4 shows an example of an RB tree being constructed from a member list.

In an embodiment of the present invention, the nodes may be, in hardware, a smartphone, a tablet personal computer, a mobile phone, a video phone, an e-book reader, a desktop PC ( desktop personal computer, laptop personal computer, netbook computer, workstation, personal digital assistant, portable multimedia player (PMP) and the like. This can include applications installed on the node. In addition, all nodes that can participate in a group have a common RB tree construction algorithm. Therefore, when nodes construct the RB tree with the same data, they form the RB tree of the same structure.

In step 210, nodes which are to form a group share a member list including identification information of corresponding nodes. For example, referring to FIG. 2, the nodes to form a group include node D 101, node B 102, node F 103, node E 104, and node H 105 (for convenience). The identification information of the nodes will be referred to as D, B, F, E, and H, respectively). One of the nodes, Node D (101), is identified to the other nodes, namely Node B (102), Node F (103), Node E (104), and Node H (105) by identifying information D, B, F, E, The member list can be shared by sending a member list containing H.

In step 220, the nodes each form an RB tree using an RB tree construction algorithm based on the identification information of the member list. As described above, since the nodes all have a common RB tree construction algorithm, the nodes all form an RB tree having the same structure. For example, referring to FIG. 4, from the member list 410 including the identification information D, B, F, E and H, the node D 101 and the node B 102 through the RB tree construction algorithm 420. An RB tree 430 is constructed, with nodes F 103, Node E 104, and Node H 105 as nodes. In the RB tree of the following drawings, for convenience, black nodes are represented without color and red nodes are represented by gray.

In step 230, the nodes identify nodes connected to themselves on the configured RB tree, that is, a parent node, a left child node, or a right child node. For example, referring to FIG. 4, node B 102 identifies node D 101, the parent node, and node D 101 identifies node B 102, the left child node, and node F ( 103, node F 103 identifies the parent node Node D 101, the left child node Node E 104, the right child node Node H 105, and node E 104 identifies the node. Node F 103, which is the parent node, is identified, and node H 105 identifies Node F 103, which is the parent node.

In step 240, each node establishes a secure session with the node associated with it. In this case, the secure session may be established as a bidirectional secure communication channel using a key exchange algorithm based on public key-based encryption such as RSA (Rivest Shamir Adleman) and ECDH (Elliptic Curve Diffie-Hellman). For example, referring to FIG. 4, a secure session is established between node B 102 and node D 101, a secure session is established between node D 101 and node F 103, and node F 103 is established. A secure session is established between node E 104 and node E 104, and a secure session is established between node F 103 and node H 105.

5 is a flowchart illustrating a process of transmitting a message from one node to other nodes in a group communication network configured by using an RB tree. FIG. 6 shows an example in which a message from one node is delivered to all nodes in the group communication network configured through FIG. 4.

In step 510, the node to transmit a message transmits the message through a secure session to a node connected to it, that is, a parent node or a child node. For example, referring to FIG. 6, a node B 102 that wants to send a message sends a message B: hello to a node D 101.

In step 520, the node receiving the message transmits the message to a node connected to the node other than the node that has sent the message through a secure session, and the process is propagated on the RB tree so that the message is delivered to all nodes. For example, referring to FIG. 6, node D 101 is a node B 102 and a node F 103 that are connected, and node B 102 sends a message to node F 103 because node B 102 has sent a message to itself. B: hello). Node F (103) is a node D (101), node E (104), and node H (105) to which the connected node is connected. Since node D (101) has sent a message to itself, node E (104) and node H ( 105) and sends a message (B: hello). Therefore, the message B: hello sent by node B102 is delivered to all other nodes.

7 is a flowchart illustrating a process of reconfiguring a group communication network by joining a new node to an already configured group communication network. FIG. 8 shows an example in which a join request message is delivered to all nodes in a group communication network, and FIG. 9 shows an example of a new RB tree being constructed from a new member list to which nodes have been added.

In step 710, a node that wants to join a group transmits a join request message to a node having node addition authority. For example, referring to FIG. 8, a node A 106 wishing to join a group transmits a join request message (A: want join) to the node D 101. Although node D 101 is an example of a node having authority to add a node, the node having authority to add a node may be multiple nodes or all nodes, or may not be a root node. The participation request message may be delivered to all nodes through a message propagation process on the RB tree or to a node having authority to add a node even though the participation request message is delivered to any node on the RB tree.

In step 720, the node having the authority to add a node transmits a member list to the node that wants to join the group, and in step 730, the node requesting the node to participate in the secure session with the node connected to the node. Send it through. For example, referring to FIG. 8, node D 101 transmits a member list including node identification information of nodes constituting the group to node A 106, and then to node B 102 and node F 103. A join request message (A: want join) of node A 106 is transmitted.

In step 740, the node receiving the join request message transmits the join request message to the node connected to the node other than the node that has sent the message through the secure session, and the process is propagated on the RB tree so that the join request message is transmitted. Passed to all nodes. For example, referring to FIG. 8, after receiving a join request message (A: want join) of node A 106 from node D 101, node F 103 sends a node to node E 104 and node H 105. A join request message (A: want join) of A 106 is transmitted. Therefore, a join request message (A: want join) of node A 106 is delivered to all nodes.

In step 750, the nodes constituting the group and the nodes to join each form a new RB tree using the RB tree construction algorithm based on the identification information of the new member list further including identification information of the nodes to join. do. For example, referring to FIG. 9, from the new member list 410 ′ including identification information A, D, B, F, E, H, which further includes identification information A of node A 106, the RB tree New RB tree with nodes D 101, Node B 102, Node F 103, Node E 104, Node H 105, and Node A 106 as configuration algorithms 420. 430 'is configured.

In step 760, the nodes and the nodes to join the group identify nodes connected to themselves on the newly formed RB tree, that is, a parent node, a left child node, or a right child node. For example, referring to FIG. 9, node A 106 identifies node B 102, the parent node, and node B 102 identifies node D 101, the parent node, and node A 106, the left child node. Node D 101 identifies node B 102, the left child node, and node F 103, the right child node, and node F 101, node D 101, the left node, parent node. Identify node E 104, the child node, node H 105, the right child node, node E 104, identify node F 103, the parent node, and node H 105, the node that is the parent node. Check F 103.

In step 770, the nodes forming the group and the nodes to join each update the security session according to the node connected to the node on the new RB tree. That is, depending on the node connected to it on the new RB tree, it establishes a secure session with the newly connected node, maintains a secure session with the previously connected node (i.e., a node which has already established a secure session), or secures with the previously connected node. End the session. For example, referring to FIG. 9, a new secure session is established between Node A 106 and Node B 103. However, since node D 101, node F 103, node E 104, and node H 105 do not change the connection relationship with other nodes in the new RB tree with the existing RB tree, To keep the session secure.

FIG. 10 shows an example in which a message from one node is delivered to all nodes in the group communication network configured through FIG. 9. When node B 103 sends a message B: hello to node A 106 and node D 101, node D 101 sends a message B: hello to node F 103, Node F 103 sends a message (B: hello) to node E 104 and node H 105, so that message B: hello sent by node B 102 is forwarded to all other nodes.

11 is a flowchart illustrating a process of reconfiguring a group communication network by withdrawing one node from a group communication network. FIG. 12 shows an example in which a withdrawal request message is delivered to all nodes in the group communication network of FIG. 10, FIG. 13 shows an example of a new RB tree being constructed from a new member list in which a node is deleted, and FIG. 14 Shows a newly configured group communication network through FIG.

In step 1110, the node that wants to leave the group transmits an exit request message to a node connected to the node through a secure session. For example, referring to FIG. 12, a node B 102 who wants to leave transmits a leave request message (B: want out) to the node A 106 and the node D 101 connected to the node B 102.

In step 1120, the node receiving the withdrawal request message transmits the withdrawal request message through a secure session to a node connected with itself other than the node that has sent the message to the node, and this process is propagated on the RB tree so that the withdrawal request message is transmitted. Passed to all nodes. For example, referring to FIG. 12, a node D 101 that has received a withdrawal request message (B: want out) from a node B 102 reads a withdrawal request message (B: want out) of the node B 102, and a node F ( Node F 103 that transmits to node E 104 and node H 105 that receives the exit request message B of the node B 102 from node D 101. Send a withdrawal request message (B: want out) of 102; Therefore, the exit request message (B: want out) of node B 102 is delivered to all nodes.

In step 1130, the nodes receiving the withdrawal request message form a new RB tree using the RB tree construction algorithm based on the identification information of the new member list except for the identification information of the node to withdraw. For example, referring to FIG. 13, from the new member list 410 '' including the identification information A, D, F, E, and H, the identification information B of the node B 102 is deleted, the RB tree construction algorithm. Through 420 a new RB tree 430 '' is constructed with nodes D 101, F 103, E 104, H 105 and A 106 as nodes. .

In step 1140, the nodes receiving the withdrawal request message check each node connected to them on the newly formed RB tree, that is, a parent node, a left child node, or a right child node. For example, referring to FIG. 13, node A 106 identifies node D 101, the parent node, and node D 101 identifies node A 106, the left child node, and node F (the right child node) ( 103, node F 103 identifies the parent node Node D 101, the left child node Node E 104, the right child node Node H 105, and node E 104 identifies the node. Node F 103, which is the parent node, is identified, and node H 105 identifies Node F 103, which is the parent node.

In step 1150, the nodes receiving the exit request message each update the security session according to the node connected to the new RB tree. That is, depending on the node connected to it on the new RB tree, it establishes a secure session with the newly connected node, maintains a secure session with the previously connected node (i.e., a node which has already established a secure session), or secures with the previously connected node. End the session. For example, referring to FIGS. 12 and 13, node A 106 terminates a secure session with node B 102 and establishes a secure session with node D 101. Node D 101 also terminates the secure session with Node B 102 and establishes a secure session with Node A 106. However, since node F 103, node E 104, and node H 105 do not change the connection relationship with other nodes in the new RB tree with the existing RB tree, the secure session with the previously connected node is maintained. do. Thus, a new group communication network as shown in FIG. 14 is constructed.

According to the embodiment of the present invention, since a device other than the node constituting the group is not required, such as a centralized device, a person other than the member of the group sends a message to a member of the group or receives a message transmitted from a member of the group. Can be blocked at source. Therefore, the data transmitted in the group can be prevented from being stored, monitored, modified, stolen or retrieved by a third party, and has the advantage of being robust against hacking attacks such as eavesdropping and man-in-the-middle attacks.

In addition, the nodes constituting the group only need to establish up to three sessions per node for communication with other nodes, so that the number of secure sessions can be reduced, thereby efficiently performing group communication.

Embodiments of the present invention can be represented by functional block configurations and various processing steps. Such functional blocks may be implemented in various numbers of hardware or / and software configurations that perform particular functions. For example, an embodiment may comprise an integrated circuit configuration such as memory, processing, logic, look-up table, etc., which may execute various functions by the control of one or more microprocessors or other control devices. You can employ them. Similar to the components in the present invention may be implemented in software programming or software elements, embodiments include C, C ++, including various algorithms implemented in combinations of data structures, processes, routines or other programming constructs. It may be implemented in a programming or scripting language such as Java, an assembler, or the like. The functional aspects may be implemented with an algorithm running on one or more processors. In addition, embodiments may employ prior art for electronic configuration, signal processing, and / or data processing. Terms such as "mechanism", "element", "means", "configuration" can be used widely and are not limited to mechanical and physical configurations. The term may include the meaning of a series of routines of software in conjunction with a processor or the like.

Specific implementations described in the embodiments are examples, and do not limit the scope of the embodiments in any way. For brevity of description, descriptions of conventional electronic configurations, control systems, software, and other functional aspects of the systems may be omitted. In addition, the connection or connection members of the lines between the components shown in the drawings by way of example shows a functional connection and / or physical or circuit connections, in the actual device replaceable or additional various functional connections, physical It may be represented as a connection, or circuit connections. In addition, unless specifically mentioned, such as "essential", "important" may not be a necessary component for the application of the present invention.

So far I looked at the center of the preferred embodiment for the present invention. Those skilled in the art will appreciate that the present invention can be implemented in a modified form without departing from the essential features of the present invention. Therefore, the disclosed embodiments should be considered in descriptive sense only and not for purposes of limitation. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the scope will be construed as being included in the present invention.

Claims (18)

In the group communication method,
Nodes that can participate in the group have a common Red-Black (RB) tree construction algorithm,
Sharing a member list including identification information of the nodes to form a group, among the nodes to form a group;
Identifying each node connected with itself on the RB tree using the RB tree construction algorithm based on the identification information of the member list, respectively, for the nodes to form the group; And
Forming a group by establishing a secure session with each of the nodes to which the group wants to form the group,
If there is a node to further participate in the group, any one of the nodes constituting the group sends a join request message of the node to participate to the node connected to the node through a secure session; And
The node receiving the participation request message further includes transmitting the participation request message through a secure session to a node connected to the node other than the node that sent the participation request message to itself, thereby all nodes configuring the group. The join request message is delivered to the group communication method. The method of claim 1,
The sharing of the member list may include sharing the member list by transmitting one of the nodes to form the group to other nodes. The method of claim 1,
Transmitting a message through a secure session to a node connected to the node which wants to transmit a message among the nodes constituting the group; And
The node receiving the message further includes transmitting the message through a secure session to a node connected to the node other than the node that has sent the message to the node, thereby transmitting the message to all the nodes in the group. Group communication method, characterized in that. delete The method of claim 1,
The new RB tree is constructed using the RB tree construction algorithm based on the identification information of the member list including the nodes constituting the group and the node to which the node to participate further includes identification information of the node to participate. Identifying nodes associated with themselves on the RB tree; And
The nodes constituting the group and the node to join each establish a secure session with a node newly connected to each other according to a node connected to the node on the new RB tree, maintain a secure session with a previously connected node, or Terminating the secure session of the group communication method. The method of claim 1,
Transmitting, by a node intending to leave the group, a leave request message to a node connected to the node through a secure session;
The node receiving the withdrawal request message further includes transmitting the withdrawal request message through a secure session to a node connected to the node other than the node that has sent the withdrawal request message to the node, thereby all nodes constituting the group. The withdrawal request message is delivered to the group communication method. The method of claim 6,
Nodes receiving the withdrawal request message each form a new RB tree using the RB tree construction algorithm based on the identification information of the member list excluding the identification information of the node to withdraw, and are connected to themselves on the new RB tree. Identifying a node; And
Each node receiving the exit request message establishes a secure session with a newly connected node, maintains a secure session with a previously connected node, or establishes a secure session with a previously connected node according to a node connected with itself on the new RB tree. And terminating the group communication method. The method of claim 1,
And the secure session is established using public key based encryption. In a group communication system,
Nodes that can participate in a group, including nodes having a common Red-Black (RB) tree construction algorithm,
Nodes wishing to form a group share a member list including identification information of nodes wishing to form the group, and nodes wishing to form the group each perform the RB tree construction algorithm based on the identification information of the member list. The RB tree is used to identify the nodes associated with itself on the RB tree, and the nodes to form the group each form a group by establishing a secure session with the node connected to the node,
If there is a node to further participate in the group, any one of the nodes constituting the group transmits a participation request message of the node to participate through a secure session to a node connected to the group, and the participation request message The node receiving the message transmits the participation request message to a node connected to itself other than the node that sent the participation request message through a secure session, so that the participation request message is transmitted to all the nodes constituting the group. Group communication system. The method of claim 9,
In order for the nodes to form the group to share the member list, one of the nodes to form the group transmits the member list to other nodes. The method of claim 9,
Among the nodes constituting the group, a node that wants to transmit a message transmits a message to a node connected to the node through a secure session, and a node that receives the message is secured to a node connected to itself other than the node that sent the message to the node. Sending the message through a session, wherein the message is delivered to all the nodes that make up the group. delete The method of claim 9,
The nodes constituting the group and the node to join each form a new RB tree using the RB tree construction algorithm based on the identification information of the member list further including identification information of the node to join. Identifying nodes connected to themselves in the RB tree, the nodes constituting the group and the nodes to join each establish a security session with a node newly connected to each other according to the node connected to the new RB tree, A group communication system for maintaining a secure session with a node or terminating a secure session with a previously connected node. The method of claim 9,
A node intending to leave the group transmits a withdrawal request message to a node connected to the node through a secure session, and the node receiving the withdrawal request message is secured to a node connected to itself other than the node that sent the withdrawal request message to the node. The withdrawal request message is transmitted to all nodes that make up the group by transmitting the withdrawal request message through a session. The method of claim 14,
Each node receiving the withdrawal request message forms a new RB tree using the RB tree construction algorithm based on the identification information of the member list except for the identification information of the node to withdraw, and is connected with itself on the new RB tree. Nodes that have checked the node and received the withdrawal request message each establish a secure session with, or maintain a secure session with, a newly connected node according to their associated node on the new RB tree. And terminate the secure session with the group. The method of claim 9,
And the secure session is established using public key based encryption. In the group communication method,
Nodes that can participate in the group have a common Red-Black (RB) tree construction algorithm,
Sharing a member list including identification information of the nodes to form a group, among the nodes to form a group;
Identifying each node connected with itself on the RB tree using the RB tree construction algorithm based on the identification information of the member list, respectively, for the nodes to form the group;
Forming a group by establishing a secure session using a node and a node connected with each other and public key based encryption, respectively;
Transmitting a message through a secure session to a node connected to the node which wants to transmit a message among the nodes constituting the group;
The node receiving the message transmits the message through a secure session to a node connected to the node other than the node that has sent the message to the node, thereby delivering the message to all the nodes in the group;
If there is a node to further participate in the group, any one of the nodes constituting the group transmits a participation request message of the node to participate to the node connected to the node through a secure session;
The node receiving the participation request message transmits the participation request message to a node connected to itself other than the node that sent the participation request message through a secure session, thereby transmitting the participation request message to all the nodes constituting the group. Is delivered;
The new RB tree is constructed using the RB tree construction algorithm based on the identification information of the member list including the nodes constituting the group and the node to which the node to participate further includes identification information of the node to participate. Identifying a node associated with itself on the RB tree; And
The nodes constituting the group and the nodes to join each establish a secure session with a node newly connected to each other according to a node connected to the node on the new RB tree, maintain a secure session with a node previously connected, or And terminating the secure session of the group. In the group communication method,
Nodes that can participate in the group have a common Red-Black (RB) tree construction algorithm,
Sharing a member list including identification information of the nodes to form a group, among the nodes to form a group;
Identifying each node connected with itself on the RB tree using the RB tree construction algorithm based on the identification information of the member list, respectively, for the nodes to form the group;
Forming a group by establishing a secure session using a node and a node connected with each other and public key based encryption, respectively;
Transmitting a message through a secure session to a node connected to the node which wants to transmit a message among the nodes constituting the group;
The node receiving the message transmits the message through a secure session to a node connected to the node other than the node that has sent the message to the node, thereby delivering the message to all the nodes in the group;
Transmitting, by a node intending to leave the group, a leave request message to a node connected to the node through a secure session;
The node receiving the withdrawal request message transmits the withdrawal request message to a node connected to itself other than the node that has sent the withdrawal request message through a secure session, thereby transmitting the withdrawal request message to all the nodes constituting the group. Is delivered;
Nodes receiving the withdrawal request message each form a new RB tree using the RB tree construction algorithm based on the identification information of the member list excluding the identification information of the node to withdraw, and are connected to themselves on the new RB tree. Identifying a node; And
Each node receiving the exit request message establishes a secure session with a newly connected node, maintains a secure session with a previously connected node, or establishes a secure session with a previously connected node according to a node connected with itself on the new RB tree. And terminating the group.

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