Security Enhancement using Chaotic Map and Secure Encryption Transmission for Wireless Sensor Networks

--Wireless Sensor Network (WSN) is a collection of variety of sensor nodes. Wireless sensor network allures the researchers with its research procedures and it is applied on various sites. Based on chaotic map and genetic operations, a lightweight block cipher is implemented to address these limitations. Elliptic curve points and one of the chaotic map parameters are employed in this cryptographic scheme to verify the communicating nodes and also output the bit sequence pseudo randomly. To encrypt the data blocks, XOR, mutation and crossover operations are used in this sequence. Chaotic map and genetic operations is mechanism used in sensor networks to provide confidentiality and security for data. In addition to Chaotic map algorithm, secure encryption transaction algorithms are used to verify the nodes by checking whether it is transferred by Authorized user or not. In future this protocol is used for audio and video encryption.

When compared to public key cryptography for WSN, the symmetric techniques of cryptography consist of own value which makes highly efficient. Sensor nodes must accomplish keys for encryption in order to provide security in WSN. The delivery of variety of keys over nodes of sensor device is referred as key distribution.

II. RELATED WORK
Number of security attacks are exposed to the transmission protocols of data which also includes clusteroriented protocols are exposed to a [12] [14]. The algorithms used are classified into three classifications for security purpose. They are conventional block cipher and lightweight block cipher and hardware based compact cryptographic schemes. Cluster head attacks in WSNs results in severe harm to the network instead out sending and aggregation of information fundamentally that depends on the cluster heads. If a hacker handles to act like attacks of selective forwarding, thereby it promotes attacks similar sink hole and damaging the network.
The present research on security is focused on design of lightweight block cipher which is more secure. Inspite of the researchers activity, most of the cryptographic schemes which is conventional is compared in which lightweight ciphers which have relatively worst execution. In order to address these limitations, cipher block based to genetic operations of chaotic map was introduced in sensor network devices combining both sender and receiver nodes which is small that enables less cost and data communication securely.
III. PROPOSED SYSTEM The proposed system aims to guarantee the data transmissions to be secure and efficient between nodes existing intermediately. The existing algorithms for encryption process tend to use key management technique for security purpose. This causes many issues. With the help of chaotic map algorithm and secure encryption techniques we try to correct those issues thereby reducing computational overhead in Secure and Efficient data Transmission-Identity Based digital Signature (SET-IBS) with the help of IBOOS scheme.

A. Network Module
In the network, nodes of sensors are located uniquely. In an undirected graph G, the nodes are connected with edges that are communicated with each other. In the graph V and E are represented in which V denotes the collection of vertices that denotes the network node set and E denotes the number of edges that denotes the travelling path location of moving nodes. Consider N as a network of travelling nodes denoted as s. N1, N2...Ns are the collection of nodes delivered in the network where 1 to s types of nodes are there. Considering any two mobile nodes Ni and Nj, delay in transmission of a data is represented as Tij. Delay is represented in unit-size that is transferred to those two nodes.

B. Bit Sequence
Bit sequence phase produces bit sequences using the algorithms chosen. The test code is used to decide the randomness of the binary sequence derived [15]. Chaotic maps algorithm involves floating point calculation to generate the random numbers continuously. They are not suited for wireless sensor networks consisting of limited resources. Chaotic map discretely influences security level which relies on never ending period and unpredictability properties of random number generation technique. Using logistic map of N frequencies provides advantage of handling the parameters which is of integer points that limits the wireless sensor network's operational computing process. The equations followed explain the chaotic functions which derive the bit sequences in the scheme implemented.
Where, ∈ 0, , ∈ 0, 4 , ∈ 0, 2 , ∈ 4, 5 , There are two principles used namely confusion and diffusion to shape the block cipher pattern. Confusion technique is the communication among the symmetric key with cipher text. Diffusion is assuming the duplicacy of the plaintext. XOR, mutation and crossover are the three operations used for the proposed scheme. XOR denotes the xor operation applied between the bit that is longer than the plaintext. The technique of considering bit strings of two parent bits and predicting the bit strings of corresponding child is referred as Crossover operation. This operation exchanges the bit string's parts between the parents. The process of combining the strings in the bits is referred as Mutation. In the cipher text, the diffusion and confusion properties are achieved with the help of mutation and crossover genetic operations. After completing the mutation operation the order of the image data and text data are changed with the help of crossover operation. A fair difference in cipher text is the advantage of using genetic operations proceeding to plaintext. D. Network Clustering   Fig 3. Shows the clustering network which consist of base station, cluster head and mobile nodes where functionalities and capabilities are homogenous in nature. The nodes of sensor may be convinced by hackers and on wireless channel, the transmission of data may be disturbed by attacks. In clustering network, group of clusters are developed by sensor nodes in which every clusters has a CH(Cluster Head). Depending on the signal strength received, clustered sensor node without cluster head is joined and the data sensed is transmitted through CH to the BS to save energy. Base station is always authentic. It implies that the base station is a confidential authority. The CHs transmit data to the BS directly thus performing data fusion and with comparatively high energy.
In wireless sensor networks, sensing of data, processing of data and transmission of data influences sensor node's energy consumption. The cost incurred in transmitting data is more costly. TDMA referred as Time Division Multiple Access control is used to send data. Thus, the node present in the middle of network (e.g., a CH) collects and combines the needed information and send back it to the base station which is better than the method in which information is received by the base station directly sent by the sensor node [16] [19]. Along with that, all sensor nodes are assumed in which the BS are coordinated with time along with corresponding radio frequency channels. The energy is constrained in which the nodes are distributed randomly. When sensor node presents idle without sensing or transmitting data, it changes into sleeping mode to save energy.

E . SET-IBS
Operations on pre-distribution of key to the nodes of sensor networks are performed by the base station. The Identity Based digital Signature scheme in the developed SET-IBS algorithm comprised of three different operations. They are signing, verification and extraction techniques. Extraction node first obtains the private key of the node. Then the generated time stamp by the channel head of a node's time interval in the current round from the TDMA control is also obtained. A random number is chosen by the sensor node and computed generation with the help of Signature signing. In Verification, authenticity is verified by each sensor node in the corresponding way upon receiving the message. After initialising the protocol, during communication SET-IBS operates in rounds. To encrypt data messages for similar encryption scheme the base station generates an encryption key k, where I is the huge integer. Considering equities, Equi= , , , , , / , 1, 2, , , ҭ, generator P of G1 is selected practically. Point mapping hash function denoting H and arbitrary input mapping h are two cryptographic hash functions. In G1, H points elements as strings and h points to fixed-length outputs.
 An integer is chosen randomly as the master key mk , Ppub=p is set as public key of the network.
 Every node of sensor network should be preloaded along the equities of the system.
, , , , , / , 1, 2, , , ҭ,  A leaf sensor node i is assumed to send a message M to its cluster head j and the data is encrypted with the help of encryption key k from homomorphic encryption scheme. The node of sensor network i selects a number randomly i=>q and computes i = E(p,P). The encrypted message's cipher text is denoted as Extraction node denoted as i first get pki as its private key from mk and IDEj, where IDEj is its identity, and ti refers the time stamp of node I that is produced by its cluster head j as time gap in the present round from the TDMA control. Then the computation of sensor node network is denoted as Where , denote the encrypted message Cj.'s digital signature node i. After receiving the message the broadcast message is then combined in which each sensor node verifies the time interval's time stamp and confirms the legal nodes and thereby checks that the received message is clean. The sensor node checks whether the received message is authorized or not. The sensor node with the help of the current time gap ti's time stamp is evaluated, if the time stamp is right. Then the message is moved to the next hop or user. The message is considered by the sensor node as either attacked or restored, if the verification fails. Although it can be a defected one and it ignores that. Then the stage starts and during communication SET-IBS operates in rounds.

F. SET-IBOOS
This phase generates the identity based online offline digital signature method. For distribution of key in the network, the following operation is done by the base station. For the homomorphic encryption scheme, exhibit an encryption key k for data messages encoding process, where k=>(N-1), N is considered as huge integer. A random generator g of group CG generation is chosen by the public key generator and also t=>Zq* is chosen as the master key mk at random. A multiplicative finite cyclic group is denoted as CG with order q. For its private key production randomly select ri=>Zq* for each and every node i.

G. Performance Evaluation
Many experiments are conducted for validation of proposed algorithms. Assumption of the uniform distribution of nodes is applied in this experiment, in the sensing field. For sink in small and large networks, the relative network behavior, throughput, overhead and lifetime is compared to cover the uncovered node using relay node. According to the number of nodes, Fig 4. represents the comparison of sender and receiver networks behavior. Fig 5. Shows the increase in data packets delivery issue considering throughput and overhead, Fig 6. illustrates the increase in lifetime of sensor network nodes.

IV. CONCLUSION
Issues related to transmission of data and security in wireless sensor network is first reviewed. After that transmission protocols for WSN are used which is secure and more efficient? The protocols used are chaotic map and genetic operations, secure encryption transmission protocols based on IBS and IBOOS scheme. For transmission of data securely, the disadvantages of the symmetric key management is discussed. The performance of the implemented schemes of SET-IBS and SET-IBOOS algorithms were analyzed in this evaluation. Routing attack analysis and security requirements were evaluated. The algorithms used are more efficient to communicate. Identity based cryptosystem is accomplished for security requirements in sensor