A cryptosystem designed by using the combined features of fractal function and chaotic map, provides a secure and real time encryption environment. In this paper, a 2D-chaotic map is employed to create a chaotic key sequence to comply with the requirement of the key sensitivity. The set of initial values of the chaotic map has derived by iterating a conjugate transcendental fractal function (CTFF) i.e. z_(n+1)=conj(sin?(z_n^2 ) )+c. The fractal function produced three sets of initial values after iterating it using Picard, Mann, and Ishikawa iteration methods. Resultantly, three chaotic key sequences will be generated by executing 2D Sine Tent composite map (2D-STCM) for each set of initial values. Afterwards, perform zigzag scanning to each key stream to decorrelate the adjacent image pixels and combined them using XOR operation. By using a different summation of plain image pixels for each pixel encryption, improves the cryptosystem resistant against known/chosen-plaintext attack. Moreover, an encryption of a plain image pixel achieved using corresponding key sequence pixel and a previously ciphered pixel value. The proposed encryption/decryption scheme is evaluated using key space analysis, key sensitivity analysis, differential analysis and other statistical analyses. The performance result indicates the given scheme is efficient and reliable to be used with great potential for a secure image transmission application.

One of the most complex environment for the data transmission is the underwater channel. It suffers frequency selective deep fading with serious multi path time delay. The channel also has limited bandwidth. In this paper, the effect of Least Code Weight – Minimum Hamming Distance (LCW-MHD) polynomial code is studied using Viterbi Decoding Algorithm for the shallow Underwater Acoustic Communication (UAC) channel. Two different channels with the range of 100 and 1000 meters are considered for simulation purpose and the channel is designed using Ray Tracing algorithm. For data and image transmission in the channel, three different code rate of 1/2, 1/3 and 1/4 are considered and corresponding Bit Error Rate (BER) are evaluated. Result showed that the BER is least for the LCG-MHD polynomial code.

Steganography is a science of security technique through invisible communication; hiding secret message into cover objects without any suspicion. Protection of the hidden information from an adversary is the main purpose of any steganography system even if the embedding method is obvious. In this paper, an effective image steganography system based on a least significant bit (LSB) algorithm and chaos is proposed. The proposed method contains a spatial domain technique in which the Logistic map is used for generating chaotic bitstream and bitwise XOR operation which is used to create control bit. Control bit determines whether the LSB of a specific pixel is changed or not according to the secret message. This provides direct manipulation over the pixels of the image with a very low precision hence enhances the system security. In this study, gray image is used as secret message and a larger scale image as cover image. Experimental results demonstrate that the proposed method is very efficient to detect LSB replacement in the algorithm. Moreover, the proposed algorithm is highly sensitive to the stego key parameters due to complex structure of chaos which provides high level of security in the whole system and effectively hides and detects the image information.

Cryptographic image block encryption schemes play a significant role in information enabled services. This paper proposes an image block encryption scheme based on a novel three stage selection (TSS) method in a public cloud with reversible cellular automata. Due to the openness of public cloud, different attacks are possible over user sensitive information. The TSS method has three stages and they generate a robust master key with user plaintext as input and produces an encrypted block as key to be sent to authenticated users. An analysis of experimental results shows that this new method has a large key space and immune to brute force attacks, statistical cryptanalysis attacks and chosen plaintext attacks. Also, the encrypted image entropy value could be increased to 7.9988 making it ideal for a best image block encryption for key generation.

SDN (software defined networks) is a programmable network architecture that divides the forwarding plane and control plane. It can centrally manage the network through a software program, i.e., controller. Multiple controllers are required to manage the current software defined WAN. Placing multiple controllers in a network is known as controller placement problem (CPP). Only one controller is not capable to handle the scalability and reliability issues. To tackle these issues, multiple controllers are required. Efficient deployment of controllers in SDN is used to improve the performance and reliability of the network. To the best of our knowledge, this is the first attempt to minimize the total average latency of reliable SDN along with the implementation of TLBO and PSO algorithms to solve CPP. Our experimental results show that TLBO outperforms PSO for publicly available topologies.

Zone Routing Protocol (ZRP) has evolved as an efficient hybrid routing protocol with extremely high potentiality owing to the integration of two radically different schemes, proactive and reactive in such a way that a balance between control overhead and latency is achieved while maintaining routng and security concerns. The execution of ZRP in any case, is affected by different system conditions, for example, zone span, arrange measure, portability and so forth. The exploration work depicted in this paper centers around enhancing the execution of zone steering convention by lessening the measure of receptive traffic which is fundamentally in charge of corrupted system execution in the event of extensive systems. The methodology is structured to such an extent that the zone range of the system stays unaffected while accomplishing better QOS(Quality of Service) execution alongside productive memory utilization.This is actualized by utilizing two calculations. The principal calculation is intended to adjust the measure of proactive and receptive traffic without expanding the zone sweep dependent on the collection of courses in a focal overseer called Head.The utilization of Route Aggregation(RA) approach helps in decreasing the steering overhead and furthermore help accomplish execution optimization.The execution of proposed convention is evaluated under fluctuating hub size and versatility. The second calculation called the firefly streamlining calculation intends to accomplish worldwide enhancement which is very hard to accomplish due to non-linearity of capacities and multimodality of calculations. Different customary improvement procedures like angle based methods, tree based calculations need to manage such issues so this exploration based work uses the meta-heuristic calculation; it takes focal points of both course total and firefly calculations to upgrade QOS of Mobile Ad-hoc Network. For execution assessment a lot of benchmark capacities are being embraced like, parcel conveyance proportion and start to finish postponement to approve the proposed methodology. Recreation results delineate better execution of proposed brand new Firefly Algorithm (FRA) when contrasted with ZRP and RA-ZRP.