WO2009067951A1

WO2009067951A1 - Method for determining multicasting proxy nodes, and method, device and system for multicasting

Info

Publication number: WO2009067951A1
Application number: PCT/CN2008/073150
Authority: WO
Inventors: Yongjun Liu
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2007-11-21
Filing date: 2008-11-21
Publication date: 2009-06-04
Also published as: CN101442419A; CN101442419B

Abstract

A method for determining multicasting proxy nodes is provided, and a method, device and system for multicasting are also provided. The method for determining multicasting proxy nodes comprises the following steps: a discovering request for multicasting proxy node is sent out by a multicasting original node; a routing cost is returned to the multicasting original node by each member in the group receiving the discovering request or by the intermediate node storing the routing information of each member of the group, in which the routing cost is the routing cost from the multicasting original node to each member node of the group; the member of the group node corresponding to the least routing cost is selected as the multicasting proxy node by the multicasting original node according to the returned routing cost. In the invention, the multicasting is implemented according to the optimal path by the multicasting original node, and the load of the multicasting proxy node is dispersed so that the problem that the same node serving as the multicasting proxy node for several multicasting original nodes becomes overload is avoided.

Description

Method for determining multicast proxy node, multicast method, device and system The application is submitted to the Chinese Patent Office on November 21, 2007, and the application number is 200710124665.3, and the invention name is "Method for determining multicast proxy node, multicast method" The priority of the Chinese application, the device and the system, the entire contents of which are incorporated herein by reference. Technical field

The embodiments of the present invention relate to the field of communications, and in particular, to a method, a multicast method, a device, and a system for determining a multicast proxy node. Background technique

Multicast, also called multicast, means that one node in the network simultaneously sends data to multiple destination nodes. Multicast technology mainly involves multicast routing, group member management, and multicast security. Among them, in terms of multicast security, it is necessary to ensure that multicast data is not obtained by unauthorized nodes, usually by encryption and decryption. In some existing networks, such as the ZigBee network, the multicast source node and the group member node respectively use the network key shared by all network nodes to encrypt and decrypt the multicast data, since the non-group member node also knows the network key. Therefore, non-group members cannot be prevented from obtaining multicast data.

In other networks, multicast source nodes and group member nodes use group keys to encrypt and decrypt multicast data. All group member nodes know or can obtain the group key, while non-group member nodes do not know the group key, thus preventing non-group member nodes from obtaining multicast data. However, the multicast source node may be a group member node or a non-group member node. When the multicast source node is a non-group member node, since the non-group member node does not grasp the group key, it cannot be directly encrypted using the group key. . The prior art solution is to set up a multicast manager in each group, which is one of the group member nodes, and manages security centrally. All multicast data initiated by non-group members is sent to the multicast manager. The multicast manager then uses the group key to encrypt the packets and then sends them to each group member node.

In the process of implementing the present invention, the inventors have found that at least the following problems exist in the prior art. Problem: All multicast data must be sent to the multicast manager first, and the routing is not necessarily optimal. Summary of the invention

The embodiment of the invention provides a method, a multicast method, a device and a system for determining a multicast proxy node, so that the multicast source node can perform multicast according to an optimal route.

The method for determining a multicast proxy node in the embodiment of the present invention includes: a multicast source node sends a multicast proxy node discovery request; and each group member node that receives the discovery request or an intermediate node that stores routing information of a group member node returns a route The cost is given to the multicast source node, and the routing cost is a routing cost of the multicast source node to each group member node; the multicast source node selects a path corresponding to the path with the lowest routing cost according to the returned routing cost The group member node acts as a multicast proxy node.

The embodiment of the present invention further provides a multicast method, a node device, and a multicast system, which can implement multicast routing optimization under the premise of satisfying multicast security requirements.

The multicast method of the embodiment of the present invention includes: the multicast source node encrypts the multicast data by using a key shared by the multicast proxy node, and then sends the multicast data according to a preset route; the multicast proxy node is a multicast source node. The group member node corresponding to the path with the lowest cost of each group member node, the preset route is the path with the least cost of the route, and the multicast data carries the destination group identifier, and the shared secret The key is a key other than the group key corresponding to the destination group identifier; after receiving the multicast data, the multicast proxy node decrypts the multicast data by using the shared key The processing is performed to the upper layer, and the decrypted multicast data is encrypted by using the group key and transmitted to other group member nodes.

The node device of the embodiment of the present invention includes: a storage unit, configured to: when the node device is used as a multicast source node, store the destination group identifier and the corresponding preset route, and the identifier of the corresponding corresponding multicast proxy node and/or a shared key between the corresponding multicast proxy node and the node device, where the multicast proxy node is a group member node corresponding to a path with the least cost route between the node device and each group member node, the pre-predetermined Let the route be the path with the least cost of the route, and the shared key is other than the group key corresponding to the destination group. The encryption unit is configured to encrypt the multicast data by using the shared key, and the sending unit is configured to send the encrypted multicast data according to the preset route.

A node device according to another embodiment of the present invention includes: a receiving unit, configured to receive multicast data from a multicast source node; and a determining unit, configured to determine whether it is a multicast proxy node corresponding to the received multicast data, The multicast proxy node is a group member node corresponding to a path with the least cost route between the multicast source node and each group member node; the decryption unit is configured to determine, in the determining unit, that the node device is a corresponding multicast And proxying the node, decrypting the multicast data by using a key shared by the multicast source node, the shared key being a key other than the group key; and an encryption unit, configured to use the The group key encrypts the decrypted multicast data, and the sending unit is configured to send the multicast data encrypted by using the group key.

The multicast system of the embodiment of the present invention includes: a multicast source node, configured to encrypt the multicast data by using a key shared by the multicast proxy node, and then send the data according to a preset route; the multicast proxy node is multicast The group member node corresponding to the route with the least cost route between the source node and the member nodes of the group, the preset route is the path with the least cost of the route, and the shared key is a key other than the group key. a multicast proxy node, after receiving the multicast data, decrypting the multicast data by using the shared key, transmitting the multicast data to a higher layer for processing, and using the decrypted multicast data The group key is encrypted and transmitted to other group member nodes.

A method for determining a multicast proxy node according to still another embodiment of the present invention includes: sending a multicast proxy node discovery request to each group member node or an intermediate node storing routing information of the group member node;

Selecting, according to the routing cost returned by the group member node or the intermediate node storing the routing information of the group member node, the group member node corresponding to the path with the lowest routing cost as the multicast proxy node, and the routing cost is the multicast The routing cost from the source node to each member node.

A multicast method according to still another embodiment of the present invention includes:

Receiving multicast data sent by the multicast source node, where the multicast data is encrypted by using the key shared by the multicast source node and shared by the multicast proxy node, and sending according to the preset route The multicast proxy node is a group member node corresponding to a path with a least cost route from the multicast source node to each member node, and the preset route is a path with the least cost of the route, and the multicast data is The destination group identifier is carried, where the shared key is a key other than the group key corresponding to the destination group identifier;

The multicast data is decrypted using the shared key and transmitted to a higher layer for processing, and the decrypted multicast data is encrypted using a group key and transmitted to other group member nodes.

Compared with the prior art, the embodiment of the invention has the following advantages:

In the embodiment of the present invention, the multicast source node selects a group member node corresponding to the path with the least route cost from the group member node or the intermediate node as a multicast proxy node, so that the multicast source node can perform multicast according to the optimal route. . DRAWINGS

1 is a flow chart of a method for determining a multicast proxy node according to Embodiment 1 of the present invention;

2 is a flowchart of a multicast method according to Embodiment 2 of the present invention;

3 is a flow chart of a method for determining a multicast proxy node according to Embodiment 3 of the present invention;

4 is a schematic diagram of a network structure in a scenario according to an embodiment of the present invention; FIG. 5 is a flowchart of a method for determining a multicast proxy node according to Embodiment 1 of the third embodiment of the present invention;

6 is a flowchart of a multicast method according to Embodiment 4 of the present invention;

7 is a flowchart of a multicast method according to Embodiment 1 of the fourth embodiment of the present invention; and FIG. 8 is a schematic diagram of a multicast system according to Embodiment 5 of the present invention. detailed description

The present invention will be further described in detail below with reference to the accompanying drawings. A first embodiment of the present invention describes a method for determining a multicast proxy node. As shown in FIG. 1, the method includes:

Step slOl, sending a multicast proxy node discovery request to each group member node or an intermediate node storing routing information of the group member node;

Step s 102: Select, according to the routing cost returned by each group member node or the intermediate node storing the routing information of the group member node, the group member node corresponding to the path with the lowest routing cost as the multicast proxy node, and the routing cost is the multicast source node. The routing cost to each member node.

In the embodiment of the present invention, the multicast source node selects a group member node corresponding to the path with the least route cost from the group member node or the intermediate node as a multicast proxy node, so that the multicast source node can perform multicast according to the optimal route. .

A second embodiment of the present invention describes a multicast method. As shown in FIG. 2, the method includes: Step s201: Receive multicast data sent by a multicast source node, where the multicast data is shared by the multicast source node and shared by the multicast proxy node. The key is encrypted and the multicast data is sent according to the preset route; the multicast proxy node is the group member node corresponding to the path with the most cost of the route from the multicast source node to the member nodes of each group, and the preset route For the route with the most cost, the multicast data carries the destination group identifier, and the shared key is the key other than the group key corresponding to the destination group identifier.

Before decrypting the multicast data by using the shared key, the method further includes: determining whether it is a multicast proxy node corresponding to the multicast data.

The method for determining whether the multicast proxy node is the multicast data is: the multicast data carries the identifier of the multicast proxy node, and is determined according to the identifier; or

The multicast data also carries the Flag flag. When the destination group is determined to be the group in which the destination group is located, and the Flag flag indicates that the multicast data is not forwarded by the group member, the group corresponding to the multicast data is determined. Broadcast proxy node; or,

The multicast data carries the multicast source node identifier, and the multicast proxy node stores the destination group identifier and the multicast source node identifier corresponding to the multicast proxy node, and the destination group identifier carried in the multicast data. The multicast source node identifier is the same as the identifier stored by itself. When it is time, it is judged that it is a multicast proxy node corresponding to the multicast data.

Step s202: Decrypt the multicast data by using the shared key, and then transmit the multicast data to the upper layer for processing, and encrypt the decrypted multicast data by using the group key and transmit the data to the other group member nodes.

According to the embodiment of the present invention, the multicast source node selects the group member node corresponding to the path with the least routing cost as the multicast proxy node from the group member nodes, so that the multicast source node can perform multicast according to the optimal route.

Embodiment 3 of the present invention describes a method for determining a multicast proxy node. As shown in Figure 3, the method includes the following steps:

Step s301: The multicast source node sends a multicast proxy node discovery request, where the discovery request carries the destination group identifier. The multicast proxy node discovery request can be sent by broadcast.

Step s302: After receiving the discovery request, each group member node determines the routing cost of the node to the multicast source node, and then returns the result to the multicast source node.

Before the discovery request arrives at each member node, it usually passes through the intermediate node, which may be a group member node or a non-group member node. After receiving a discovery request, a node can determine whether it is a member node of the group according to the destination group identifier carried in the discovery request. If it is a member node of the group, it returns the routing cost information to the multicast source node. That is, the non-group member node;), accumulates the routing cost from the previous hop to its own, and then forwards the multicast proxy node discovery request to its neighbor until it reaches the group member node.

Each group member node can return all routing costs to the multicast source node. Here, "all routing costs" theoretically refers to the route corresponding to all objective existing paths of the multicast source node to each group member node according to the network structure. The cost, but in fact, the multicast source node usually presets a period of time, and after the preset time is over, it no longer receives the returned route cost. Therefore, "all routing costs" usually refers to the routing cost of each path within a preset time.

Each group member node can also compare the routing costs of each path first, and only return the minimum routing cost. It can also return to the multicast source node after receiving the discovery request for the first time. The routing cost of the requesting transmission path is found for the first time. When the discovery request is received for the second time, it is determined whether the routing cost corresponding to the second discovery request transmission path is smaller than the routing cost corresponding to the first discovery request transmission path. Returns the smaller route cost, if not, does not return, and records the smaller route cost. When each subsequent discovery request is received, it is compared with the previous smaller routing cost. If it is smaller, the smaller routing cost is returned, otherwise it is not returned.方式 Compare and return to the smaller or the smallest, and reduce the number of returns relative to returning all routing costs, thereby reducing the signaling interaction of each node on the way back, which is beneficial to reduce network load.

In addition, if an intermediate node stores its own routing information to each group member node, the intermediate node can directly return the routing cost to the multicast source node after receiving the discovery request. The routing cost here may be the sum of the routing cost of the multicast source node to the intermediate node and the routing cost of the intermediate node to each group member node, and preferentially, the minimum route from the multicast source node to the intermediate node. The cost is the sum of the minimum routing cost of the intermediate node to each group member node, because the number of returns can be reduced.

Step s303: The multicast source node selects, according to the routing cost information returned by the member nodes of each group, a group member node corresponding to the path with the smallest routing cost as the multicast proxy node of the destination group.

The application example 1 of the method of the third embodiment in the network shown in Fig. 4 will be described below. FIG. 4 is a schematic diagram of a network structure in a scenario according to an embodiment of the present invention. Nodes A, B, C, D, and E belong to a group member of a multicast group G, and all members in the group G share one. Group key Kg, the non-group member node cannot obtain this group key. Node S is a non-group member and needs to send multicast data to each group member node of group G. That is to say, in this multicast process, node S is a multicast source node.

In the network, as shown in FIG. 5, the method for determining the multicast proxy node is as follows: Step s501: The multicast source node S broadcasts a multicast proxy node discovery request to its neighbor nodes K and I, and discovers the request at the multicast proxy node. The request carries the identifier and routing cost of the destination group G. Here, the initial value of the routing cost is 0.

Step s502: After receiving the multicast proxy node discovery request, the node K determines, according to the identifier of the destination group G, that it does not belong to the group G, and therefore, accumulates the route generation from S to K. The price is 1, and then the multicast proxy node discovery request is re-broadcasted. The routing cost carried in the request is the accumulated routing cost, that is, 1. After receiving the multicast proxy node discovery request re-broadcasted by the node K, the node A determines that it belongs to the group member of the group G according to the identifier of the destination group G. Therefore, the route cost from K to A is accumulated 1.2, and the accumulated route is obtained. The cost is 2.2, and the accumulated routing cost is returned to the multicast source node S. Similarly, the group member node A also receives the multicast proxy node discovery request forwarded by other non-group member nodes (for example, node I), and accumulates the routing cost, and returns the accumulated routing cost to the multicast source node S. It should be noted that the group member node A may also separately accumulate the routing cost in the multicast proxy node discovery request forwarded by each non-group member, that is, the routing cost of different paths of the multicast source node S to A, and then select one of them. The minimum routing cost, and the lowest routing cost is returned to the multicast source node S.

Other group member nodes: 8, C, D, and E also receive the multicast proxy node discovery request forwarded by the non-group member node, and add the route cost to the multicast source node. There are two ways to return, that is, to return the routing cost of different paths respectively, or to select the smallest one from the routing costs of different paths and then return the minimum routing cost.

Step s503: The multicast source node S selects a group member node corresponding to the path with the lowest route cost as the multicast proxy node of the destination group G according to the routing cost returned by the member nodes of each group. For example, if a group member node returns the routing cost of multiple paths, if the minimum routing cost selected by the multicast source node is one of the routing costs of the multiple paths, the group member node is used as a multicast proxy. node. In this case, the multicast source node can also select the minimum of multiple routing costs returned by the same group of member nodes, and then compare the minimum values of the routing costs returned by each group member node, and finally obtain the minimum value. The corresponding group member node is a multicast proxy node. In the case that only one routing cost is returned for each group member node, the multicast source node directly selects the group member node corresponding to the path with the least routing cost as the multicast proxy node. In this application embodiment, the multicast source node determines that the route cost corresponding to the A node is the smallest, and therefore uses the node A as its multicast proxy node.

It should be noted that the group member node A is only a multicast proxy node for the group G and the source node S, and different multicast source nodes, or different groups, multicast proxy nodes. May be different.

Next, a specific application example 2 of the method of the third embodiment in the network shown in Fig. 4 will be described.

In this embodiment, the intermediate node from the multicast source node S to the group member nodes of the group G stores related routing information, and the intermediate node may be a group member node or a non-group member node. For example, the intermediate node K stores the routing information of K to the group member nodes A, B, C, D, and E. The stored routing information may be the minimum routing cost information of K to a single group member node, or may be the minimum routing cost information obtained by comparing the minimum routing cost corresponding to each group member node.

In this embodiment, after receiving the multicast proxy node discovery request and knowing that the destination group is the group G, the node directly returns the routing cost information to the multicast source node according to the routing information stored in the group G. That is, the routing cost stored by the member nodes of each group is added to the routing cost of K to S, and then the accumulated routing cost is returned to the node A.

Embodiment 4 of the present invention describes a multicast method. As shown in FIG. 6, the multicast method includes the following steps:

Step s601: The multicast source node encrypts the multicast data by using a key shared by the multicast proxy node, and then sends the multicast data according to a preset route. The multicast proxy node is a group member node corresponding to the path with the highest route cost from the multicast source node to the member nodes of each group. It is pre-determined and stored in the multicast source node, and the determined method may be The method for determining a multicast proxy node in the foregoing first embodiment may also use other methods. The preset route is a route with the least cost between the multicast source node and the multicast proxy node, and is also determined and stored in the multicast source node, and may be determined by using the method in the foregoing Embodiment 1, or may be determined. Use other methods to determine. The shared key may be a key other than the group key corresponding to the multicast data, and may be a point-to-point key, a multi-point-to-point key, or a point-to-multipoint key. The multi-point-to-point key can be determined by the multicast proxy node and its corresponding multiple multicast source nodes by negotiation, distribution, and the like.

Step s602: After receiving the multicast data, the multicast proxy node decrypts the multicast data by using the shared key, transmits the multicast data to the upper layer for processing, and uses the decrypted multicast data to use the group secret. The key is encrypted and transmitted to other group member nodes.

Before decrypting the multicast data, the multicast proxy node may first determine whether it is the multicast proxy node corresponding to the received multicast data. There are a plurality of methods for judging. One method is: when the multicast source node sends the multicast data, it carries the identifier of the multicast proxy node, and after receiving the multicast data, the multicast proxy node determines according to the identifier; In the method, when the multicast source node sends the multicast data, it carries the destination group identifier and the Flag flag. When the multicast proxy node receives the multicast data, if the destination group is found to be the group in which it belongs, and the Flag flag indicates the multicast. When the data is not forwarded by the group member, it is judged that it is the multicast proxy node corresponding to the received multicast data. The third method is to carry the destination group identifier and group when the multicast source node sends the multicast data. The source node identifier is identified, and the group identifier and the multicast source node identifier corresponding to the multicast proxy node are stored in the multicast proxy node (the multicast proxy node can obtain the information from each multicast source node in advance and store the information. When the destination group identifier and the multicast source node identifier carried in the received multicast data are consistent with the identifiers stored by the multicast data, it is determined. It is the corresponding multicast proxy node. Among the three methods, the first two methods are preferred, which are simple and convenient, and consume less signaling.

The application example of the multicast method in the fourth embodiment will be described in detail below with reference to the network shown in FIG.

In the application embodiment 1, the multicast method is as follows. As shown in FIG. 7, the method includes the following steps: Step s701: The multicast source node S encrypts the multicast data packet by using the point-to-point key Ks shared by the multicast proxy node A. The payload portion of the frame is encrypted with Ks). The trailing edge is sent out by a preset route. The data packet carries the identifier of the destination group G (in this embodiment, the destination group address) and a Flag flag. The initial value of the flag is 0, indicating that the data packet is not forwarded by the group member node. If the multicast packet has been forwarded by the multicast member, Flag becomes 1. Table 1 shows a possible frame format for a multicast packet, including the Flag flag, the source node address, and the destination group identifier. Table 1 A possible frame format for multicast packets

In this embodiment, the multicast source node stores a shared key including each multicast group and corresponding route, a corresponding multicast proxy node, and the multicast source node. As shown in Table 2, in the routing table, the identifier of the multicast group G is represented by its address, which is 0x1234. At the same time, the routing table also stores the minimum cost route from S to A. Before sending a multicast packet, the multicast source node searches its own routing table based on the destination group address to obtain the corresponding route and shared key. In this embodiment, the multicast source node may also store the multicast proxy node identifier corresponding to each shared key.

Table 2 Routing Table 1

Step s702: The multicast data packet arrives at the node K according to the preset route, and the node K determines that the destination group identifier of the data packet is not the group in which it is located, and therefore forwards according to the preset route. Since K does not know the key Ks, the content of the packet cannot be intercepted.

In step s703, the multicast data packet arrives at node A according to the preset route, and according to the destination group identifier, it is determined that the destination group is the group in which it is located, and then the value of Flag is checked to be 0, so that it is determined that it is a multicast proxy node. At the same time, the node A knows that the source node is S according to the source node address. Therefore, the data packet is decrypted using the key Ks shared with the S, and then transmitted to the upper layer for processing. Moreover, the node A changes the value of the Flag identifier to 1, re-encrypts the multicast data packet using the group key Kg, and then transmits the multicast data packet between the nodes in the group, which may be multicast or used. Broadcast or unicast. Step s704: After the multicast node: 8, C, D, and E receive the multicast data packet, determine, according to the destination group identifier, that the destination group is the group in which it belongs, and check that Flag=l, therefore, directly use the group. The key Kg decrypts the data packet and transmits it to the upper layer for processing, and transmits the data packet to the members of other groups.

It can be understood that, in this embodiment, the process of sending a data packet according to a preset route may be implemented by using multiple routing algorithms. For example, the AODV algorithm may be used to record only the next hop in the routing table. The address can also use the DSR algorithm to record the address of the full path in the routing table, and the remaining full routing node address in the sent multicast packet.

In the application embodiment 2, the difference from the application embodiment 1 is that the proxy node identifier is stored in the multicast source node, and is represented by the proxy node address. As shown in Table 3, the multicast source node stores the destination group identifier (here represented by the destination group address) and the corresponding route and proxy node address. The multicast source node also stores a shared key of each multicast proxy node and the multicast source node. When the multicast source node sends a multicast packet, it carries the destination group identifier and the identifier of the multicast proxy node. The identifier of the multicast proxy node is determined in advance and stored in the multicast source node. The method for determining the multicast proxy node may use the method for determining the multicast proxy node in the foregoing first embodiment, or may use other methods. After receiving the multicast data packet, each node on the preset route determines whether the multicast proxy node identifier in the data packet is its own identifier. If yes, the key shared by the multicast source node is used for decryption, and is transmitted to The high-level processing, at the same time, uses the group key Kg corresponding to the destination group identifier to encrypt the data packet and transmit between the nodes in the group. If not, continue to forward down according to the preset route.

Table 3 Routing Table 2

In Application Example 3, unlike the application embodiment 1, the multicast proxy node stores its own multicast source node and multicast group information corresponding to the multicast proxy node. The data frame contains the multicast source node identifier (for example, it can be a multicast source node address). When the multicast proxy node receives the multicast data packet, it determines that it is the corresponding multicast proxy node according to the destination group identifier and the multicast source node identifier in the data packet, and uses the key shared with the multicast source node. The decryption is transmitted to the upper layer processing, and at the same time, the packet is encrypted using the group key Kg and transmitted between the nodes in the group.

It will be understood that, although the above embodiments have been described in order to facilitate the understanding of the steps of the method, it should be noted that the order of the above steps is not strictly limited.

It will be understood by those skilled in the art that all or part of the steps of the foregoing embodiments may be implemented by a program instructing related hardware, and the program may be stored in a computer readable storage medium, the storage medium It can be ROM/RAM, disk, CD, etc.

Embodiment 5 of the present invention describes a multicast system. As shown in FIG. 8, the multicast system includes a multicast source node 8000 and a multicast proxy node 8002.

The source node 8000 specifically includes a storage unit 8004, an encryption unit 8006, and a transmission unit 8008. The storage unit 8004 is configured to store the destination group identifier and the corresponding preset route, and the corresponding multicast proxy node identifier and/or the shared key between the corresponding multicast proxy node and the node device. The destination group identifier may be the address of the destination group, and the multicast proxy node identifier may be the address of the multicast proxy node, and the preset route is the path with the lowest routing cost between the multicast source node 8000 and the corresponding multicast proxy node. The shared key is a key other than the group key corresponding to the destination group, that is, the group key corresponding to the destination group identifier. Encryption unit 8006 is for encrypting the multicast data using a key (e.g., a point-to-point key) shared with the corresponding multicast proxy node. The shared key cannot be the group key of the corresponding destination group. The sending unit 8008 is configured to send the encrypted multicast data according to a preset route.

The multicast proxy node 8002 includes a receiving unit 8018, a determining unit 8016, a decrypting unit 8014, an encrypting unit 8012, and a transmitting unit 8010. Wherein, the receiving unit 8018 uses After receiving the multicast data from the multicast source node 8000, the determining unit 8016 is configured to determine whether the multicast proxy node 8002 is a multicast proxy node corresponding to the received multicast data. If so, the decryption unit 8014 decrypts the multicast data using the shared key described above for transmission to higher layer processing. The judging unit 8016 may use a plurality of judging methods, for example, the three methods described in step 602 may be employed. The encryption unit 8012 is configured to re-encrypt the decrypted multicast data using the group key, and then the re-encrypted data is transmitted by the transmitting unit 8010 to the other group member nodes.

It will be understood that the drawings (or in the embodiments) are merely illustrative and represent logical structures in which the units shown as separate components may or may not be physically separated, and the components displayed as a unit may be Or it may not be a physical unit, that is, it can be located in one place or distributed to several network units. For example, the transmitting unit 8010 and the receiving unit 8018 may be physically located in one place to synthesize the transceiver unit, and the encrypting unit 8012 and the decrypting unit 8014 may also be located in one place and combined into an encryption and decryption unit.

According to the embodiment of the present invention, the multicast source node selects the group member node corresponding to the path with the least routing cost as the multicast proxy node from the group member nodes, so that the multicast source node can perform multicast according to the optimal route. Moreover, the multicast source node encrypts the multicast data by using a key other than the group key, which satisfies the requirements of multicast security. In addition, for different multicast source nodes, the multicast proxy nodes may be different, thereby dispersing the burden of the multicast proxy node, and avoiding the problem that the same node is overburdened as a multicast proxy node of different multicast source nodes.

The drawings and the related description are merely illustrative of the principles of the invention and are not intended to limit the scope of the invention. For example, the present invention can be applied to any type of communication network, wired network, fixed network, satellite network, etc., and is not limited to the network structure shown in FIG. Therefore, any modifications, equivalents, improvements, etc. made within the spirit and scope of the present invention are included in the scope of the present invention.

Claims

Rights request

A method for determining a multicast proxy node, the method comprising: the multicast source node sending a multicast proxy node discovery request;

The group member node that receives the discovery request or the intermediate node that stores the routing information of the group member node returns a routing cost to the multicast source node, where the routing cost is the multicast source node to each group member node. Routing cost

The multicast source node selects a group member node corresponding to the path with the lowest route cost as the multicast proxy node according to the returned routing cost.

2. The method of claim 1 wherein

The routing cost returned by the group member node is the minimum routing cost of the multicast source node to the group member node.

3. The method according to claim 1, wherein the routing cost returned by the intermediate node is: a minimum routing cost of the member node to each group and a minimum routing cost of the multicast source node to the intermediate node. Sum.

4. A method according to claim 1, 2 or 3, characterized in that

The discovery request carries a destination group identifier;

The group member node that receives the discovery request returns a routing cost to the multicast source node, and the node that receives the discovery request determines whether it is a group member node according to the destination group identifier, and if yes, returns Routing the cost to the multicast source node; if not, forwarding the discovery request until the group member node is reached.

5. A multicast method, comprising:

The multicast source node encrypts the multicast data by using a key shared by the multicast proxy node, and then sends the multicast data according to a preset route; the multicast proxy node is the least costly route between the multicast source node and each group member node. The group member node corresponding to the path, the preset route is the path with the least cost of the route, the multicast data carries the destination group identifier, and the shared key is the group key corresponding to the destination group identifier. Other keys outside;

After receiving the multicast data, the multicast proxy node decrypts the multicast data by using the shared key, and then transmits the multicast data to a higher layer for processing, and the decrypted multicast number is used. After being encrypted using the group key, it is transmitted to other group member nodes.

The multicast method according to claim 5, wherein before the multicast proxy node decrypts the multicast data by using the shared key, the method further includes: the multicast proxy node determining itself Whether it is a multicast proxy node corresponding to the multicast data.

The multicast method according to claim 6, wherein the method for determining whether it is the multicast proxy node corresponding to the multicast data is:

The multicast data further carries a multicast proxy node identifier, and the multicast proxy node determines according to the identifier; or

The multicast data further carries a Flag flag, and when the multicast proxy node determines, according to the destination group identifier, the destination group is the group in which the group is located, and the Flag flag indicates that the multicast data is not forwarded by the group member. Determining that it is a multicast proxy node corresponding to the multicast data; or

The multicast data carries a multicast source node identifier, where the multicast proxy node stores the destination group identifier and the multicast source node identifier corresponding to the multicast proxy node, when the multicast data is in the multicast data. When the carried destination group identifier and the multicast source node identifier are consistent with the identifiers stored by the multicast destination node, the multicast proxy node corresponding to the multicast data is determined.

8. Method according to claim 5, 6 or 7, characterized in that the shared key is a point-to-point key.

9. A node device, comprising:

a storage unit, configured to store the destination group identifier and the corresponding preset route, and the identifier of the corresponding corresponding multicast proxy node and/or the corresponding multicast proxy node and the node when the node device is used as the multicast source node a shared key between the devices, the multicast proxy node is a group member node corresponding to a path with the least cost route between the node device and each group member node, and the preset route is a path with the least cost of the route The shared key is a key other than the group key corresponding to the destination group;

The encryption unit is configured to encrypt the multicast data by using the shared key, and the sending unit is configured to send the encrypted multicast data according to the preset route.

10. A node device, comprising:

a receiving unit, configured to receive multicast data from a multicast source node;

a determining unit, configured to determine whether it is a multicast proxy node corresponding to the received multicast data, where the multicast proxy node is a path corresponding to a path with the least cost route between the multicast source node and each group member node Group member node;

a decryption unit, configured to: when the determining unit determines that the node device is a corresponding multicast proxy node, decrypt the multicast data by using a key shared by the multicast source node, where the shared key Other keys than the group key;

An encryption unit, configured to encrypt the decrypted multicast data by using the group key;

And a sending unit, configured to send the multicast data encrypted by using the group key.

11. A multicast system, comprising:

a multicast source node, configured to encrypt the multicast data by using a key shared by the multicast proxy node, and then send the multicast data according to a preset route; the multicast proxy node is a route between the multicast source node and each group member node. The group member node corresponding to the least cost path, the preset route is the path with the least cost of the route, and the shared key is a key other than the group key;

a multicast proxy node, after receiving the multicast data, decrypting the multicast data by using the shared key, and transmitting the multicast data to a higher layer for processing, and using the decrypted multicast data to use the group The key is encrypted and transmitted to other group member nodes.

12. A method for determining a multicast proxy node, the method comprising: sending a multicast proxy node discovery request to each group member node or an intermediate node storing routing information of the group member node;

13. A multicast method, comprising:

Receiving multicast data sent by the multicast source node, where the multicast data is the multicast source section The point is encrypted by using a key shared by the multicast proxy node, and the multicast data is sent according to a preset route; the multicast proxy node is a path corresponding to a path with the least cost route between the multicast source node and each group member node. The group member node, the preset route is a path with the least cost of the route, and the multicast data carries the destination group identifier, where the shared key is other than the group key corresponding to the destination group identifier. key;

The multicast method according to claim 13, wherein before decrypting the multicast data by using the shared key, the method further includes:

Determine whether it is the multicast proxy node corresponding to the multicast data.

The multicast method according to claim 14, wherein the method for determining whether it is a multicast proxy node corresponding to the multicast data is:

The multicast data further carries a multicast proxy node identifier, and is determined according to the identifier; or

The multicast data further carries a Flag flag. When the destination group is determined according to the destination group identifier, the destination group is the group in which the group belongs, and the flag indicates that the multicast data is not forwarded by the group member. The multicast proxy node corresponding to the multicast data; or the multicast data carries the multicast source node identifier, and the multicast proxy node stores the destination group identifier and group corresponding to the multicast proxy node The source node identifier is determined to be the multicast proxy node corresponding to the multicast data when the destination group identifier and the multicast source node identifier carried in the multicast data are consistent with the identifiers stored by the multicast source node.