CN101742490A - Safe and effective wireless sensor network program dynamic update method - Google Patents

Abstract

The invention discloses a safe and effective method for dynamically updating a wireless sensor network program, belonging to the field of wireless communication. The method comprises the following steps of: determining an euclidean space by a base station and dividing the euclidean space into a first subspace and a second subspace which are orthogonal to each other before deploying sensor nodes; randomly selecting a standard orthogonal basis of the first subspace, and randomly selecting a vector for each sensor node from the second subspace; determining a hash function, and selecting a same random number for all the sensor nodes as a cluster key; installing the vector, the cluster key and the hash function into each sensor node; broadcasting program updating message to a sensor network by the base station when the base station needs to update the programs on all the sensor nodes, and checking the validity of the message by each sensor node; if the program updating message is valid, receiving the program updating message by the sensor node and updating programs per se; otherwise, rejecting the program updating message.

Description

Safe and effective wireless sensor network program dynamic update method

technical field

The invention relates to a method for dynamically updating programs, which belongs to the field of wireless communication.

Background technique

In recent years, wireless sensor networks have attracted the attention of a large number of researchers because of their broad application prospects. In most cases, the base station needs to update the program on the sensor nodes. The base station here refers to the server connected to the sensor network and has unlimited resources. Recently, many secure dynamic program update mechanisms for wireless sensor networks have been proposed, some of which are not suitable for resource-constrained sensor networks because of the use of digital signatures, an energy-intensive operation, and some other mechanisms have been pointed out to have security vulnerabilities . Therefore, up to now, there has not been a safe and effective method for dynamically updating programs in wireless sensor networks.

Contents of the invention

The purpose of the present invention is to provide a safe and effective wireless sensor network program dynamic update method.

The technical solution adopted by the present invention to solve the technical problems is: the safe and effective wireless sensor network program dynamic update method mainly includes the following steps:

1) Before the deployment of sensor nodes, the base station performs the following operations:

Determine a Euclidean space, and decompose the Euclidean space into two orthogonal first subspaces and second subspaces; randomly select an orthonormal basis of the first subspace, and for each sensor node from the first Randomly select a vector in the second subspace;

Determine a hash function and choose the same random number as the cluster key for all sensor nodes;

installing the vector, cluster key and hash function into each sensor node;

2) After the sensor nodes are deployed, when the base station updates the programs on all sensor nodes, the base station broadcasts a program update message to the sensor network, which includes the time stamp of message sending, the updated program, and the program version number , the identifier of the program, the hash function value with the cluster key as input, and auxiliary information used to check the validity of the program update message;

3) After each sensor node receives the program update message, it verifies the validity of the message. If the program update message is valid, the sensor node accepts the program update message and updates its own program; otherwise, it rejects the program update message.

Compared with prior art, the advantage of the present invention is:

(1) The present invention realizes the safety of the system through the principle of matrix orthogonality, which is simple and reliable, so it is especially suitable for wireless sensor networks with limited resources;

(2) The sensor node has carefully verified the program update message so that it can effectively resist various

Such attacks, especially the use of cluster keys, can effectively resist wormhole attacks;

(3) In order to update the programs on all sensor nodes, the base station only needs to send a unique broadcast message.

(4) The length of the program update information in the present invention is fixed and has nothing to do with the number of nodes in the sensor network, so it is suitable for large-scale wireless sensor network program update.

Description of drawings

Fig. 1 is a working flowchart of the method for dynamically updating wireless sensor network programs of the present invention.

Detailed ways

The relevant technical terms are as follows:

M program

Identifier of the X ^pid program M

Version of X ^VER program M

h one-way hash function

异或操作

XOR operation

A·B The dot product of matrix A and matrix B

^AT Transpose of matrix A

A. Before the deployment of sensor nodes, the base station selects an n-dimensional Euclidean space V, and decomposes V into two orthogonal first subspace V ₁ and second subspace V ₂ , where V ₁ is k-dimensional, V ₂ is nk dimension. The base station then randomly selects an orthonormal basis {Q ₁ , Q ₂ ,...,Q _k } of V ₁ ; and selects a vector C i for each sensor node _i , i=1, 2K, k, where C _i is an element belonging to _V2 . The base station determines a hash function, and then selects the same m-bit random number x _B as the cluster key for all sensor nodes. m should be large enough, such as 256, which means that x _B is a random number with high information entropy . Then, vector C _i , hash function h and cluster key x _B are loaded into each sensor node.

B. After the sensor nodes are deployed, when the program needs to be updated, the base station sends a program update message M _ddv ^(j) to all sensor nodes, $m_{\mathrm{adv}}^{\left(j\right)}\stackrel{\mathrm{\Δ}}{=}\{j,t_j,m{,x}^{\mathrm{pid}},x^{\mathrm{ver}},h(j,t_{j,},m,x^{\mathrm{pid}},x^{\mathrm{ver}},x_B),\mathrm{\β}{o}_j^T\},$ Where j=1, 2Kk, j represents the program update sequence number, which is an auxiliary information used to check the validity of the program update message; t _j represents the timestamp sent by the message M _ddv ^(j) ; M represents the updated program, X ^pid represents the identifier of the program, X ^ver represents the version number of the program, and β is a vector satisfying the relationship h(j, t _j , M, X ^pid , X ^ver , x _B )·β=0.

C. When any sensor node i receives the message M _ddv ^(j) , perform the following operations on the validity verification of the program update message:

1) Verify the validity of j: if j is less than or equal to j ^* stored in the sensor node, the sensor node rejects the message; otherwise, the sensor node considers j to be fresh and replaces j ^* with j (initially, The sensor node stores j ^* = 0), and proceed to the next step.

2) Verify the validity of t _j : the current time of the sensor node is Clock, if |Clock-t _j |<Δt, proceed to the next step; otherwise, the sensor node rejects the message. Here Δt is the preset time delay threshold;

3) Next, the sensor node uses the stored cluster key x _B to calculate h(j, t _j , M, X ^pid , X ^ver , x _B ), and the calculated h(j, t _j , M, X ^pid , X ^ver , x _B ) is compared with the corresponding hash function value h(j, t _j , M, X ^pid , X ^ver , x _B ) in M _adv ^(j) , if the two are not equal, the sensor The node rejects the message; if both are equal, proceed to the next step.

4) The sensor node calculates h(j, t _j , M, X ^pid , X ^ver , x _B ) ^T βO _j ^T , if it is equal to 0, proceed to the next step; otherwise, the sensor node rejects the message;

5) The sensor node randomly selects a non-zero row vector R _j ^T from βO _j ^T , multiplies R _j ^T with the C _i stored in node i, if the result is 0, proceed to the next step; otherwise the sensor node reject the message;

6) The sensor node checks whether R _j is a linear combination of R ₁ , R ₂ K R _j-1 , if not, stores R _j , inserts R _j into the vector set {R ₁ , R ₂ K R _j-1 }, Accept the message; otherwise reject the message.

Each sensor node performs the above series of checks on the validity of the program update message for the received program update message. If the message can pass all checks, the sensor node accepts the program update message and performs program update. Dynamic update; otherwise, the sensor node rejects the program update message.

Claims (1)

1. method for dynamically updating wireless sensor network program safely and effectively is characterized in that may further comprise the steps:

1) before sensor node deployment, following operation is carried out in the base station:

Determine an Euclidean space, and this Euclidean space is decomposed into first subspace and second subspace of two quadratures; Select an orthonormal basis of first subspace at random, and from second subspace, select a vector at random for each sensor node;

Determine a hash function, and be that all sensor nodes select an identical random number as bunch key;

Described vector, bunch key and hash function are installed in each sensor node;

2) behind sensor node deployment, when the base station is upgraded the program on all the sensors node, the base station is to sensor network radio program updating message, this program updating message comprises timestamp that message sends, the identifier of the program after upgrading, program version number, program, with bunch key as the hash function value of input be used for the supplementary of validity of check problem updating message;

3) after each sensor node is received program updating message, utilize bunch key stored, verify the validity of this message, if this program updating message is effective, then sensor node is accepted this program updating message and is upgraded self program; Otherwise refuse this program updating message.

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