CN107148013A - A source location privacy protection method based on multi-phantom node strategy - Google Patents

Abstract

A kind of source position method for secret protection based on many phantom facility strategies, it includes, and netinit, node ternary set constructor, phantom node are alternately chosen, source node phantom node is based on sector region division forwarding and phantom Node base station avoids visible area forwarding.The present invention is that source node produces two phantom nodes simultaneously using many phantom node thoughts, and constitutes node triple, and cause any two node in triple can as the 3rd node alternative phantom node；In addition source data packet forwarding is carried out in route working stage combination sector region division methods and visible area avoidance strategy, not only can be effectively increased source node security by avoiding source node visible area, while extending to route energy consumption during preferable controlling transmission.

Description

A source location privacy protection method based on multi-phantom node strategy

technical field

The invention relates to a network technology, in particular to a network and communication technology, in particular to a source location privacy protection method of a multi-phantom node strategy.

Background technique

Wireless Sensor Network (WSN) has been widely used in smart home, military defense, traffic management, environmental monitoring, medical Health, emergency rescue, industrial manufacturing and other fields. Because wireless sensor network nodes are often deployed in relatively remote and unattended environments, and wireless multi-hop communication methods are vulnerable to attackers, network security has always been a problem that cannot be ignored. Therefore, a lot of research has focused on the security research of wireless sensor networks.

At present, there are many security research directions in wireless sensor networks, which can be mainly divided into data encryption methods, identity authentication, key management, attack detection and defense, security routing protocols, and privacy issues. Among them, the privacy of wireless sensor networks includes location privacy, time privacy and data privacy. Among them, node location privacy, including source node location privacy and base station node location privacy, is one of the important concerns of wireless sensor network privacy. For example, in a sensor network deployed in a wildlife monitoring environment, the location information of the monitoring object (that is, the wild animals that may appear in the environment) is extremely important. Once it is leaked to a threat object (such as a predator), the safety of the monitoring object will exist. Great threat. Therefore, it is of great significance to study the source location privacy protection technology of wireless sensor networks for the large-scale deployment and application of sensor networks.

Ozturk et al. first proposed the "Panda-Hunter" model, which became the basic model for studying the privacy protection of source node locations. In this model, wireless sensor network nodes are deployed in the environment where pandas live to monitor the living habits of pandas. The monitoring data is sent to the base station in the network by forwarding data packets hop by hop between nodes through the node that has detected the target. According to this model, the goal of designing the source location privacy protection protocol is to change the original shortest path routing and forwarding data packets, and increase the time for attackers (ie hunters) in the network to track the location of the source node, that is, the security time of the source node. In addition, considering the factors of network performance, relevant privacy protection protocols should also consider ensuring the strength of privacy protection while optimizing data packet transmission delay and network energy consumption to improve the performance of the protocol.

The existing research work divides the attackers in WSN into two categories: local traffic attackers with relatively limited attack capabilities and global traffic attackers with strong attack capabilities. For the more common local traffic attackers, Ozturk et al. proposed the idea of phantom routing strategy for the first time, and proposed the phantom routing protocol PR (Phantomrouting) and the phantom single-path routing protocol PSPR (Phantom Single-path routing). The methods of the two routing strategies are to generate a false source node by randomly walking the specified number of hops (such as custom h hops) through the source data packet of the source node, which is called a phantom source node. Then the phantom node sends the source data packet to the base station to complete the transmission of the source node monitoring event data. Wang et al. first proposed the concept of the source node's visible area, which is defined as: the source node is located within a certain monitoring range of the attacker, that is, the position of the source node is exposed, and the range of a circle with the source node as the center and a specified radius R This is called the "viewable area". Based on this definition, the routing path passing through the visible area in the phantom single-path stage is also called the failure path. For this kind of local attacker with visibility ability, the general source location privacy protection scheme based on phantom routing strategy is not effective, so It is particularly important to study a source location privacy protection scheme with the ability to avoid visible regions.

Contents of the invention

The purpose of the present invention is to solve the problem of poor effect of the existing source location privacy protection scheme based on phantom routing strategy, and to invent a source location privacy protection method that solves the multi-phantom node strategy based on the "Panda-Hunter" model.

Technical scheme of the present invention is:

A source location privacy protection method based on a multi-phantom node strategy, characterized in that it comprises the following steps:

Step 1: The network is initialized; the base station initializes flooding data packets to common nodes in the entire network, and each node reports its own relevant information to the base station Sink through a message packet after completion; after the initialization phase is completed, all nodes in the network get The minimum hop value of the base station, the base station Sink holds the geographical location information of each node, and the shortest hop value between each node and the base station;

Step 2: Node triplet construction; according to the hop value between the network node and the base station obtained by the base station after the initialization phase, the base station creates a hop distance value table, sorts the nodes according to the hop value in the table, and creates node triplets in turn; In the routing working stage, any two nodes in each triplet can be used as the phantom source node of another node;

Step 3: The routing work stage starts after any node monitors the target event. First, store the monitoring event information, source node ID, source node coordinates, target node ID and target node coordinates in the data packet, and enter the routing work stage; Phantom node alternate selection process, each round alternately selects one of the two candidate phantom nodes to forward the source data packet;

Step 4: After step 3 is completed, perform source node-phantom node forwarding based on fan-shaped area division; limit the forwarding path range of source data packets, and ensure the randomness of the path at the same time, so as to deal with the attacker's backtracking attack;

Step 5: After step 4 is completed, the source data packet is forwarded by the phantom node-base station avoiding the visible area; the next-hop node is selected to avoid the visible area by calculating the distance between the relay node and the source node.

In step 2, in the process of constructing base station node triplets, it is calculated to ensure that the candidate phantom node pairs are located outside the visible range of the source node; assuming that the geographic location coordinates of the source node S are (x _s , y _s ), the candidate phantom node The coordinates are (x _p , y _p ), so that the phantom node does not fall within the range of the visible area, the conditions should be met:

In order to ensure that the distance between two phantom nodes is large enough to avoid each other's visible area, the candidate phantom nodes should meet the following conditions:

In the formulas (1) and (2), d _{p_min} is the minimum limit value of the distance between any two nodes in the node triplet set by the network initialization, d _{s_p} is: the distance between the phantom node and the source node d _{p_p} is: two The distance between phantom nodes; R _V is the radius of the visible area of the source node; through the above calculations to ensure that when any two nodes in the node triplet are phantom nodes, the phantom node is far enough away from the source node and completely avoids the possible Viewport extent.

The alternate selection strategy of phantom nodes in step 3 is:

The network node internally stores a selection flag SelectFlag, which is set to FLASE during initialization. Before the source node starts sending source data packets, it judges the selection flag. If the flag is FALSE, the phantom node 1 of the source node is selected as The phantom node that sends data in this round, and the ID _P1 of phantom node 1 and the position coordinates (x _P1 , y _P1 ) are added to the data packet, set as the phantom node ID and coordinates of the target phantom node to send in this round, and the selection flag The bit value is set to TRUE; if the flag bit is TRUE, the phantom node 2 of the source node is selected as the phantom node sending data in this round, and the ID of phantom node 2 is ID _P2 and the position coordinates are (x _P2 , y _P2 ) add the data packet, set it as the target phantom node ID and coordinates of the current round, and set the value of the flag bit to FALSE; through the above alternate selection mechanism of the flag bit, it can be ensured that the data packets of adjacent timings are sent to different target phantom nodes, It effectively prevents the chance that the path is easy to repeat due to the duplication of phantom nodes.

The forwarding steps of the source node-phantom node adopted by each relay node in step 4 based on fan-shaped area division are as follows:

Step 4.1: Set the parameter sector division angle β, the number of divided sub-sectors L and the communication radius R _t ;

Step 4.2: Obtain the coordinates (x _P , y _P ) of the phantom node selected in this round from the source data packet;

Step 4.3: Obtain the coordinates (x _C , y _C ) of this node from the internal storage of the current node;

Step 4.4: Calculate the distance d _{C_P} between the current node C and the phantom node P;

Step 4.5: Judging whether d _{C_P} is less than or equal to the communication radius R _t , if it is less than or equal to, it will be forwarded directly to the phantom node P, and this stage is over, entering the stage of forwarding avoiding the visible area; otherwise, go to step 4.6;

Step 4.6: Use the parameter L to generate an integer random number V; L is the number of divided sub-fan areas, and V is a natural number;

Step 4.7: Use the current node C and the target phantom node P to generate a fan angle in the range of (-β, β), and use random numbers and fan angles to divide the parameters to generate a random sub-fan area angle range θ as the currently selected random sub-fan area vector;

Step 4.8: Sequentially calculate the angle between the straight line formed by the node N _i in the set of neighbor nodes and the current node C, and the straight line formed by the nodes C and P;

Step 4.9: If there is a node N _i located in the sub-sector area vector, deliver the source data packet to the N _i node; if not, go to step 4.6 and regenerate the random number V to select a random sub-sector area;

Step 4.10: Repeat the above steps until the source data packet is delivered to the phantom node P.

Step 5: In the phantom node-base station avoiding the visible area forwarding, assuming that the next hop coordinates are (x _n , y _n ), according to the definition of the visible area range, the next hop node should satisfy the formula:

In the formula: x _s , y _s are the geographic location coordinates of the source node S, and d _{s_n} is the distance between the source node S and the next hop coordinate point n;

Each relay node divides the neighboring nodes into two sets: the far node set and the near node set. The hop value of the base station is larger than that of the current node; in order to control the transmission delay, the data packet will be sent to the base station as soon as possible, and the node located in the near node set of the current relay node will be selected for forwarding.

The beneficial effects of the present invention are:

The source location privacy protection method proposed by the present invention, for attackers with visibility, can not only make the forwarding path avoid the visible area of the source node through operations such as node triplet construction, thereby effectively increasing the security of the source node, but also through The method based on fan-shaped area division can better optimize the transmission delay and routing energy consumption, and enhance the practicability of the privacy protection method.

Description of drawings

Figure 1 is a schematic diagram of the principle of the multi-phantom node method EMPRP.

Figure 2 is the overall framework of the source location privacy protection protocol EMPRP based on the multi-phantom node strategy.

FIG. 3 is a flow chart of a source node-phantom node forwarding method based on fan-shaped area division.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figure 1-3.

A source location privacy protection method of a multi-phantom node strategy, which comprises the following steps:

Step 1: The network is initialized. The base station initializes by flooding data packets to common nodes, and each node reports its own relevant information to the base station through data packets after completion. After the initialization phase is completed, all nodes in the network obtain the minimum hop value with the base station, the base station holds the geographic location information of each node, and the shortest hop value between each node and the base station. This step provides enough data for the node triplet construction process.

Step 2: Node triplet construction. According to the hop value obtained by the base station after the initialization phase, the base station creates a hop distance value table, sorts the nodes according to the hop value in the table, and creates node triplets in turn. In the routing working stage, any two nodes in each triple can be used as the phantom source node of another node.

Step 3: Phantom nodes are selected alternately. The routing work stage starts after any node monitors the target event. First, the monitoring event information, source node ID, source node coordinates, target node ID, and target node coordinates are stored in the data packet, and enter the routing work stage. Firstly, the alternate selection process of phantom nodes is carried out, and one of the two candidate phantom nodes is alternately selected in each round to forward the source data packet. The alternate selection process ensures that data packets in adjacent timings are sent to different phantom nodes, which increases the difficulty of backtracking for the attacker to ensure the privacy of the source location.

Step 4: The source node-phantom node divides and forwards based on the fan-shaped area. This step ensures that the source data packet will be forwarded along a fan-shaped area between the source node and the phantom node, thereby avoiding the unlimited random walk of the source data packet, thereby effectively controlling the transmission delay and energy consumption. The division of multiple sub-sector areas and random selection and forwarding ensure the randomness and diversity of routing paths, thus increasing the difficulty of backtracking for attackers.

Step 5: Phantom node-base station avoids visible zone forwarding. In this step, the distance between the relay node and the source node is calculated to ensure that the relay node is located outside the scope of the visible area, thereby effectively avoiding failure paths and increasing the privacy protection strength of the source location.

The details are as follows:

As shown in Figure 1, it is a schematic diagram of the principle of the present invention. The source node S sets two phantom nodes at the same time, namely P ₁ and P ₂ , and the distance between P ₁ and P ₂ and the source node is greater than the radius of the visible area. , so that the phantom node effectively avoids the scope of the visible zone; the process of forwarding the source data packet to the base station is divided into two stages: the phantom routing stage and the forwarding stage avoiding the visible zone. In the phantom routing stage, one of the two phantom nodes is randomly selected, and the data packet is forwarded based on the fan-shaped area forwarding method between the source node and the phantom node. The candidate next-hop nodes are limited to the fan-shaped area of size 2β, and the child The fan-shaped area selects the next hop node; avoids the visible area and calculates the distance of the candidate node in the forwarding stage to ensure that the visible area is avoided and the failure path is avoided, thereby increasing the security time of the source node.

As shown in FIG. 2 , the present invention is divided into two stages of network configuration and routing work as a whole. Network configuration is divided into two steps: network initialization and node triplet construction. The routing work stage is divided into three steps: alternate selection of phantom nodes, source node-phantom node forwarding based on fan-shaped area division, and phantom node-base station forwarding avoiding the visible area.

1. Network initialization uses the base station to flood data packets to common nodes for initialization, and each node reports its own relevant information to the base station through data packets after completion. After the initialization phase is completed, all nodes in the network obtain the minimum hop value with the base station, the base station holds the geographic location information of each node, and the shortest hop value between each node and the base station.

2. The base station constructs network node triplets to construct phantom node pairs that are located outside the visible range for the source node. This step selects two phantom nodes for each node in the network to form a node triplet Triple(N ₁ ,N ₂ ,N ₃ ), where N _i (i=1,2,3) all represent sensor nodes, and triple Any two nodes in the group can be phantom nodes for each other, and the routing work stage randomly selects one of the phantom nodes to forward data packets through random number generation. The specific implementation of the base station node triplet is as follows:

Step 2.1: Initialize parameters d _{p_min} and R _V . d _{p_min} is the minimum limit value of the distance between any two nodes in the node triplet set by network initialization, and R _V is the radius of the visible area to ensure that when any two nodes in the node triplet are phantom nodes, the phantom The node is far enough away from the source node and completely avoids the scope of the viewport.

Step 2.2: Assume that the geographic coordinates of the source node S are (x _s , y _s ), and the coordinates of the candidate phantom nodes are (x _p , y _p ), in order to prevent the phantom nodes from falling within the visible area, according to the two-dimensional plane The calculation of the physical distance between internal nodes should meet the following conditions:

In order to ensure that the distance between two phantom nodes is large enough to avoid each other's visible area, the candidate phantom nodes should meet the following conditions:

Select appropriate phantom node pairs by formulas (1) (2) to form node triplets.

Step 2.3: The base station sends a data packet to inform the node of the ID and coordinates of the other two nodes in the node triplet. After the node receives it, the ID and coordinates of the phantom node pair are stored in the node respectively, and are used as the candidate phantom of the node node pair. Let the IDs of two phantom nodes be ID _P1 and ID _P2 respectively, and the corresponding coordinates are (x _P1 , y _P1 ), (x _P2 , y _P2 ) respectively. In the routing work phase, each round of data packet transmission will select one of these two nodes as a phantom node and add the corresponding ID and coordinate information to the data packet.

3. The source node sends the source data packet to the phantom node to carry out the alternate selection process of the phantom node to ensure that the data packets of adjacent timing are sent to different phantom nodes, so as to increase the difficulty of the attacker's attack. The specific implementation method is:

Step 3.1: The network node internally stores a Boolean variable SelectFlag as a selection flag, which is set to FLASE during initialization.

Step 3.2: Before the source node starts to send the source data packet, judge the selection flag bit, if the flag bit is FALSE, select the phantom node 1 of the source node as the phantom node sending data in this round, and set the phantom node 1 The ID is ID _P1 and the position coordinates (x _P1 , y _P1 ) are added to the data packet, set as the target phantom node ID and coordinates sent in this round, and the value of the selection flag is set to TRUE; if the flag is TRUE, select The phantom node 2 of the source node is selected as the phantom node sending data in this round, and the ID _P2 of phantom node 2 and the position coordinates (x _P2 , y _P2 ) are added to the data packet, and set as the phantom sending target in this round Node ID and coordinates, and set the value of the flag to FALSE.

4. As shown in Figure 3, the source node-phantom node used by the source node and the relay node is based on the fan-shaped area division. The specific implementation method is as follows:

Step 4.1: Set the parameter sector division angle β, the number of divided sub-sectors L and the communication radius R _t .

Step 4.2: Obtain the coordinates (x _P , y _P ) of the phantom node selected in this round from the source data packet.

Step 4.3: Obtain the coordinates (x _C , y _C ) of the current node from the internal storage of the current node.

Step 4.4: Calculate the distance d _{C_P} between the current node C and the phantom node P. The calculation method is:

Step 4.5: Determine whether d _{C_P} is less than or equal to the communication radius R _t , if it is less than or equal to, forward it directly to the phantom node P, this stage is over, and enter the forwarding stage avoiding the visible area; otherwise, go to step 4.6.

Step 4.6: Use the parameter L to generate an integer random number V, and the generation method is:

Step 4.7: Use the current node C and the target phantom node P to generate a fan angle in the range of (-β, β), and use the random number V and the fan angle to divide the parameters to generate a random sub-fan area angle range θ, as the currently selected random sub-fan A vector of regions, the range of which is:

Step 4.8: Calculate in turn the angle between the straight line formed by the node N _i in the set of neighbor nodes and the current node C, and the straight line formed by nodes C and P. The calculation method is:

Step 4.9: If there is a node N _i located in the sub-sector area vector, deliver the source data packet to the N _i node; if not, go to step 4.6, and regenerate the random number V to select a random sub-sector area.

Step 4.10: Repeat the above steps until the source data packet is delivered to the phantom node P.

5. In the phantom node-base station avoiding the visible zone forwarding, assuming that the next hop coordinates are (x _n , y _n ), the specific implementation method for selecting the next hop node is as follows:

Step 5.1: Each relay node divides the neighbor nodes into two sets: the far node set and the near node set. The hop value of the node from the base station is larger than the current node. In order to control the transmission delay, the data packet is sent to the base station as soon as possible, and the node located in the near node set of the current relay node is selected for forwarding. First judge whether the candidate node belongs to the near node set; if yes, go to step 5.2.

Step 5.2: According to the definition of the scope of the visible area, the next hop node should satisfy the formula:

If the node satisfies formula (3), it is the next hop forwarding node.

The parts not involved in the present invention are the same as the prior art or can be solved by using the prior art.

Claims (5)

1. a source location privacy protection method based on many phantom node strategies, is characterized in that: it comprises the following steps: Step 1: The network is initialized; the base station initializes flooding data packets to common nodes in the entire network, and each node reports its own relevant information to the base station Sink through a message packet after completion; after the initialization phase is completed, all nodes in the network get The minimum hop value of the base station, the base station Sink holds the geographic location information of each node, and the shortest hop value between each node and the base station; Step 2: Node triplet construction; according to the hop value between the network node and the base station obtained by the base station after the initialization phase, the base station creates a hop distance value table, sorts the nodes according to the hop value in the table, and creates node triplets in turn; In the routing working stage, any two nodes in each triplet can be used as the phantom source node of another node; Step 3: The routing work stage starts after any node monitors the target event. First, store the monitoring event information, source node ID, source node coordinates, target node ID and target node coordinates in the data packet, and enter the routing work stage; Phantom node alternate selection process, each round alternately selects one of the two candidate phantom nodes to forward the source data packet; Step 4: After step 3 is completed, perform source node-phantom node forwarding based on fan-shaped area division; limit the forwarding path range of source data packets, and ensure the randomness of the path at the same time, so as to deal with the attacker's backtracking attack; Step 5: After step 4 is completed, the source data packet is forwarded by the phantom node-base station avoiding the visible area; the next-hop node is selected to avoid the visible area by calculating the distance between the relay node and the source node. 2. The source location privacy protection method based on the multi-phantom node strategy according to claim 1, characterized in that: in step 2, during the construction of the base station node triplet, it is ensured by calculation that the candidate phantom node pairs are all located at the source node. Outside the scope of the viewing area; assuming that the geographic location coordinates of the source node S are (x _s , y _s ), and the coordinates of the candidate phantom nodes are (x _p , y _p ), in order to prevent the phantom nodes from falling within the scope of the viewing area, it should satisfy condition: <mrow> <msub> <mi>d</mi> <mrow> <mi>S</mi> <mo>_</mo> <mi>p</mi> </mrow> </msub> <mo>=</mo> <msqrt> <mrow> <msup> <mrow> <mo>(</mo> <msub> <mi>x</mi> <mi>p</mi> </msub> <mo>-</mo> <msub> <mi>x</mi> <mi>s</mi> </msub> <mo>)</mo> </mrow> <mn>2</mn> </msup> <mo>+</mo> <msup> <mrow> <mo>(</mo> <msub> <mi>y</mi> <mi>p</mi> </msub> <mo>-</mo> <msub> <mi>y</mi> <mi>s</mi> </msub> <mo>)</mo> </mrow> <mn>2</mn> </msup> </mrow> </msqrt> <mo>&amp;GreaterEqual;</mo> <msub> <mi>d</mi> <mrow> <mi>p</mi> <mo>_</mo> <mi>m</mi> <mi>i</mi> <mi>n</mi> </mrow> </msub> <mo>&gt;</mo> <msub> <mi>R</mi> <mi>v</mi> </msub> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>1</mn> <mo>)</mo> </mrow> </mrow> In order to ensure that the distance between two phantom nodes is large enough to avoid each other's visible area, the candidate phantom nodes should meet the following conditions: <mrow> <msub> <mi>d</mi> <mrow> <mi>p</mi> <mo>_</mo> <mi>p</mi> </mrow> </msub> <mo>=</mo> <msqrt> <mrow> <msup> <mrow> <mo>(</mo> <msub> <mi>x</mi> <mrow> <mi>p</mi> <mn>1</mn> </mrow> </msub> <mo>-</mo> <msub> <mi>x</mi> <mrow> <mi>p</mi> <mn>2</mn> </mrow> </msub> <mo>)</mo> </mrow> <mn>2</mn> </msup> <mo>+</mo> <msup> <mrow> <mo>(</mo> <msub> <mi>y</mi> <mrow> <mi>p</mi> <mn>1</mn> </mrow> </msub> <mo>-</mo> <msub> <mi>y</mi> <mrow> <mi>p</mi> <mn>2</mn> </mrow> </msub> <mo>)</mo> </mrow> <mn>2</mn> </msup> </mrow> </msqrt> <mo>&amp;GreaterEqual;</mo> <msub> <mi>d</mi> <mrow> <mi>p</mi> <mo>_</mo> <mi>m</mi> <mi>i</mi> <mi>n</mi> </mrow> </msub> <mo>&gt;</mo> <msub> <mi>R</mi> <mi>v</mi> </msub> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>2</mn> <mo>)</mo> </mrow> </mrow> In the formulas (1) and (2), d _{p_min} is the minimum limit value of the distance between any two nodes in the node triplet set by the network initialization, d _{s_p} is: the distance between the phantom node and the source node d _{p_p} is: two The distance between phantom nodes; R _V is the radius of the visible area of the source node; through the above calculation to ensure that when any two nodes in the node triplet are phantom nodes, the phantom node is far enough away from the source node and completely avoids the possible Viewport extent. 3. The source location privacy protection method based on multi-phantom node strategy according to claim 1, characterized in that: the alternate selection strategy method of phantom nodes in step 3 is: The network node internally stores a selection flag SelectFlag, which is set to FLASE during initialization. Before the source node starts sending source data packets, it judges the selection flag. If the flag is FALSE, the phantom node 1 of the source node is selected as The phantom node that sends data in this round, and the ID _P1 of phantom node 1 and the position coordinates (x _P1 , y _P1 ) are added to the data packet, set as the phantom node ID and coordinates of the target phantom node to send in this round, and the selection flag The bit value is set to TRUE; if the flag bit is TRUE, the phantom node 2 of the source node is selected as the phantom node sending data in this round, and the ID of phantom node 2 is ID _P2 and the position coordinates are (x _P2 , y _P2 ) Add data packets, set as the current round sending target phantom node ID and coordinates, and set the value of the flag bit to FALSE; through the above flag bit alternate selection mechanism, it can ensure that the data packets of adjacent timings are sent to different target phantom nodes, It effectively prevents the probability that the path is easy to repeat due to the duplication of phantom nodes. 4. The source location privacy protection method based on the multi-phantom node strategy according to claim 1, characterized in that: the source node-phantom node adopted by each relay node in step 4 is divided into forwarding steps based on fan-shaped areas: Step 4.1: Set the parameter sector division angle β, the number of divided sub-sectors L and the communication radius R _t ; Step 4.2: Obtain the coordinates (x _P , y _P ) of the phantom node selected in this round from the source data packet; Step 4.3: Obtain the coordinates (x _C , y _C ) of this node from the internal storage of the current node; Step 4.4: Calculate the distance d _{C_P} between the current node C and the phantom node P; Step 4.5: Judging whether d _{C_P} is less than or equal to the communication radius R _t , if it is less than or equal to, it will be forwarded directly to the phantom node P, and this stage is over, entering the stage of forwarding avoiding the visible area; otherwise, go to step 4.6; Step 4.6: Use the parameter L to generate an integer random number V, where L is the number of divided sub-fan areas, and V is a natural number; Step 4.7: Use the current node C and the target phantom node P to generate a fan angle in the range of (-β, β), and use the random number V and the fan angle to divide the parameters to generate a random sub-fan area angle range θ, as the currently selected random sub-fan region vector,; Step 4.8: Sequentially calculate the angle between the straight line formed by the node N _i in the set of neighbor nodes and the current node C, and the straight line formed by the nodes C and P; Step 4.9: If there is a node N _i located in the sub-sector area vector, deliver the source data packet to the N _i node; if not, go to step 4.6 and regenerate the random number V to select a random sub-sector area; Step 4.10: Repeat the above steps until the source data packet is delivered to the phantom node P. 5. The source location privacy protection method based on the multi-phantom node strategy according to claim 1, characterized in that: in step 5 phantom node-base station avoiding the visible zone forwarding, it is assumed that the next hop coordinates are (x _n , y _n ), according to the scope definition of the visible area, the next hop node should satisfy the formula: <mrow> <msub> <mi>d</mi> <mrow> <mi>s</mi> <mo>_</mo> <mi>n</mi> </mrow> </msub> <mo>=</mo> <msqrt> <mrow> <msup> <mrow> <mo>(</mo> <msub> <mi>x</mi> <mi>n</mi> </msub> <mo>-</mo> <msub> <mi>x</mi> <mi>s</mi> </msub> <mo>)</mo> </mrow> <mn>2</mn> </msup> <mo>+</mo> <msup> <mrow> <mo>(</mo> <msub> <mi>y</mi> <mi>n</mi> </msub> <mo>-</mo> <msub> <mi>y</mi> <mi>s</mi> </msub> <mo>)</mo> </mrow> <mn>2</mn> </msup> </mrow> </msqrt> <mo>&gt;</mo> <msub> <mi>R</mi> <mi>v</mi> </msub> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>3</mn> <mo>)</mo> </mrow> </mrow> In the formula: x _s , y _s are the geographic location coordinates of the source node S, and d _{s_n} is the distance between the source node S and the next hop coordinate point n; Each relay node divides the neighboring nodes into two sets: the far node set and the near node set. The hop value of the base station is larger than that of the current node; in order to control the transmission delay, the data packet will be sent to the base station as soon as possible, and the node located in the near node set of the current relay node will be selected for forwarding.