Selective encryption algorithms have been proposed to encrypt syntax elements such as intra prediction modes, the sign bit of nonzero DCT coefficients, along with the sign bit of motion vectors. These syntax elements are sensitive enough to produce effective scrambling effect with a relative low computational cost. In this paper, a novel scheme is proposed to further optimize the computational overhead incurred by the encryption for energy critical multimedia applications. The proposed scheme adjusts the selection of syntax elements to be encrypted according to the scene transitions within adjacent video frames. The ratio of intra-coded macroblocks in inter (P and B) frames is calculated and compared with an adaptive threshold value to detect the scene transitions. Furthermore, based on statistical analysis for a few video sequences, a dynamic threshold model to detect the scene transition is proposed. When there is a scene transition between the previous video frame and the current video frame, intra prediction modes and the sign bit of DCT coefficients in the current frame are chosen as syntax elements to be encrypted, whereas in the absence of a scene transition, the sign bit of motion vectors is chosen as the only sensitive syntax elements to be encrypted. Experimental results show that compared with previous work in this field, the proposed scheme can efficiently lower the computational cost incurred by the encryption while maintaining a similar perceptual scrambling effect.

This paper presents a new technique for copyright protection of images using integer wavelet transform (IWT), singular value decomposition (SVD) and Arnold transform. We divide the cover image into four sub-images by picking alternate pixels from consecutive rows and columns and embed the copyright mark into the sub-image having the largest sum of singular values. The embedding is done by modifying singular values of the IWT coefficients of the selected sub-image. The use of Arnold transform and SVD increases security and robustness against geometric and several signals processing attacks, while IWT provides computational efficiency. We compare the performance of our technique with state-of-the-art-methods. The experimental results show that the proposed technique is more imperceptible and achieves higher security and robustness against various signal processing (filtering, compression, noise addition, histogram equalization and motion blur) and geometrical (cropping, resizing, rotation) attacks.

The scalability and stability in wireless sensor networks (WSNs) are considering as an important issue due to the large numbers of nodes and consequently their node density and deployment. While the network size increase, the need of scalable and efficient routing protocols is indispensable. Moreover, sensor nodes have to be alive to guarantee the network operation for the period which the first node died doesn’t appear. This period, named network stability region, is ameliorated by many techniques. In fact, the balancing energy consumption and clustering method are among those techniques. In this paper, we present the scalability and stability analysis of the routing protocol LEACH based on K-means clustering algorithm (KLEACH). Accordingly, the simulation results of the performance metrics verify the efficiency and the scalability of KLEACH protocol compared to LEACH.

In this paper we present a new algorithm for clustering MANET by considering several parameters. This is a new adaptive load balancing technique for clustering out Mobile Ad-hoc Networks (MANET). MANET is special kind of wireless networks where no central management exits and the nodes in the network cooperatively manage itself and maintains connectivity. The algorithm takes into account the local capabilities of each node, the remaining battery power, degree of connectivity and finally the power consumption based on the average distance between nodes and candidate cluster head. The proposed algorithm efficiently decreases the overhead in the network that enhances the overall MANET performance. Reducing the maintenance time of broken routes makes the network more stable, reliable. Saving the power of the nodes also guarantee consistent and reliable network.

MANET is a decentralized network that has no infrastructure and nodes can communicate with each other by multi-hoping the messages. Due to this nature of MANET, it is prone to many security attacks in which packet drop attacks are very common. Various packet drop attacks like Blackhole attacks, Grayhole attack, Co-operative Blackhole attack, etc are the attacks that become a bottleneck in efficient routing and security in MANET. Various mechanisms are devised in past but none of them prove to be effective against all types of packet drop attacks. In this paper, a mechanism is formulated that enhances the AODV routing protocol with Trueness Level and Cryptography for effectively counter all types of packet drop attacks by mitigating them through avoidance and elimination of source of attack after detection. This mechanism is powered by efficient use of Cryptography in its natural form. This work is compared with published work Extended Data Routing Information mechanism against various parameters like Packet Delivery Ratio, Normalized Control Load, Accuracy and Reliability in the same environment and parameters in MATLAB 2013a.

In this paper we explore a mechanized verification of the NTRUEncrypt scheme, with the formal proof system Isabelle/HOL. More precisely, the functional correctness of this algorithm, in its reduced form, is formally verified with computer support. We show that this scheme is correct what is a necessary condition for the usefulness of any cryptographic encryption scheme. Besides, we present a convenient and application specific formalization of the NTRUEncrypt scheme in the Isabelle/HOL system that can be used in further study around the functional and security analysis of NTRUEncrypt family.

Elliptic Curve Scalar multiplication is the method of adding a point on the curve to itself every time[1]. In recent years, research in Scalar Multiplication over Elliptic curves (EC) over a finite fields attracted many researchers, working in field of cryptography, to find out how elliptic curves cryptography (ECC) can be implemented and how to reduce its complexity [4]. The efficient techniques used in Elliptic curve cryptography are Elliptic curve scalar multiplication using point-halving algorithm [2], then double-base (DB) chain algorithm, and after that step multi-base representation (SMBR), but these techniques have their drawbacks. So, it become imperative to find out a new approach which can be efficiently used for implementation of ECC and further reducing its complexity. The paper proposes a new algorithm Treble algorithm for affine coordinates. We continued doing work using the binary concept or double and add operation with the help of treble approach to make it more efficient which relates to the use of all input values in producing any type of output, including how much time and energy are required The results show that our contribution can significantly enhance EC scalar multiplication.

Pulse shaping filter when applied to the symbols generated for transmission in a bandwidth limited systems allow for bandwidth containment that reduces the Inter-Symbol Interference (ISI) arising from multipath signal reflections which further minimizes the probability of errors at the receiver. Wavelets encompass the advantages of transforming and mapping data onto orthogonal subcarriers with optimal flexibility as well as less complexity which leads to increase the bandwidth efficiency of an Orthogonal Frequency Division Multiplexing (OFDM) system. In this paper Square Root Raised Cosine (SRRC) a pulse shaping technique when applied to Discrete Wavelet Transform (DWT) based OFDM system in mobile WiMax is simulated and its performance analysis in terms of Bit Error rate (BER) as a function of Signal to Noise Ratio (SNR) is investigated for various modulation schemes under AWGN channel. The results obtained show that SRRC filter offers to significantly improve BER for the given SNR and enhance the performance of physical layer in Mobile WiMax. The performance measurements and analysis is done in the simulation developed in MATLAB.