Shailender Gupta

Reachability Analysis of Mobility Models under Idealistic and Realistic Environments

The mobility models are used to represent the unpredictable movement pattern of the nodes in Mobile Ad-hoc Network (MANET) and give us an idea regarding their location, velocity and acceleration change over time. These models are used for simulation purpose in standard software tools such as QualNet, ns-2 etc. This paper evaluates the performance of routing protocols for mobility models such as Random Way Point (RWP), Random Walk (RW) and Random Direction (RD) under idealistic and realistic conditions based on a parameter termed as Probability of Reachability (POR). The POR is defined as the fraction of reachable routes to all possible routes between all pairs of sources and destinations. For this purpose a simulator is designed in MATLAB. We observe a marked difference in value of POR under idealistic and realistic conditions.

An innovative image encryption scheme based on chaotic map and Vigenère scheme

Confidentiality of images during data communication is a prime concern of many researchers, as a result, several mechanisms have been proposed for image encryption. An encryption for image is said to be effective if it has large key space, aperiodic nature and sensitive to the initial conditions. In addition, it is also desired that the mechanism must have a good combination of computational speed, security and time complexity. These features can be induced in the encryption schemes by incorporation of chaos during encryption/decryption process. In this paper, a novel image encryption scheme based on chaotic maps and Vigenère Scheme is proposed. This scheme has one round consisting of two steps: diffusion and confusion. The former step involves three stages: forward diffusion, matching process using Vigenère scheme and backward diffusion. In later part, position permutation using chaotic map is used to swap pixel positions. The proposed as well as other mechanisms in literature are implemented in Matlab-2015 and their efficacy are compared using several performance metrics. The simulation results show that our scheme is better in terms of time complexity while keeping Peak Signal to Noise Ratio (PSNR) values same and having almost ideal entropy, Number of Pixels Change Rate (NPCR) and Unified Average Changing Intensity (UACI).

Towards realistic performance evaluation of Mobile Ad Hoc Network

Mobile Ad-Hoc Network (MANET) is a self-configuring network of mobile nodes connected by wireless links to form an arbitrary topology without the use of existing infrastructure. In order to facilitate communication between a pair of nodes, routing protocols are used. The performance of routing protocols is evaluated using simulation tools such as QUALNET, NS-2 and MATLAB etc. Simulation tool provides researchers with a number of significant benefits, including repeatable scenarios, isolation of parameters, and exploration of a variety of metrics. We wish to make these simulations more realistic for ad hoc network. To do the same different shapes such as square, elliptical, circular and rectangular of the simulation region were taken. In addition to different shapes, we used the concept of obstacle. These obstacles restrict node movement as well as obstruct the communication path between nodes. Simulation results show that for same number of nodes deployed having equal areas and with different shapes the throughput will have inverse relationship with perimeter. The result can be very useful while designing a routing protocol.

A novel hybrid security mechanism for data communication networks

With the growing internet technology over the last decade, the number of intruders trying to steal the confidential information has also risen. As a result, for the protection of secret data from unwanted access, hybrid security mechanisms employing the use of steganography to hide the encrypted data are gaining popularity. These mechanisms provide an extra level of security to the data. This paper proposes a hybrid mechanism that not only aims at providing good security but at the same time has high data embedding capacity and entropy values with low execution time complexity. To enhance the embedding capacity of the overall system, Improved Bit Plane Complex Steganography (IBPCS) along-with Huffman coding is used and for providing randomness, the use of chaos process wherever possible is done. The cryptographic technique employed is hierarchical visual cryptography due to its efficiency over other cryptographic mechanisms. The overall scheme is implemented in MATLAB-10 and the results prove that the proposed mechanism is efficient to other available schemes in literature.

Impact of area's shape on MANET performance

The Mobile Ad hoc Networks (MANETs) are normally deployed in the disaster affected areas where there is a big damage to infrastructural resources or in the military operations in the remote areas, where the infrastructural resources are virtually nonexistent. The performance of these networks is known to be dependent upon various parameters such as transmission range, mobility, bandwidth and residual power of the nodes, and the network size. Literature provides the study of the impact of these parameters on the MANET performance. This paper provides the impact of a new parameter, the shape of the area where the ad hoc network is to be deployed, on the performance of ad hoc networks through simulation in MATLAB.

A fuzzy-based routing protocol for cognitive radio networks

With the growing spectrum demand over the last decade, the use of cognitive radio networks (CRN) has provided a viable solution to spectrum scarcity problem. These networks basically employ two types of users: primary user (PU) and secondary user (SU). The PUs are allocated a license to use the spectrum at their will. On the other hand the SUs communicates via other SUs or through the licensed spectrum of PU nodes opportunistically. In such a scenario it is important that routing protocol that is deployed must take into consideration the stability of the route. Therefore, this paper proposes a novel fuzzy-based routing strategy with this objective in mind. Further, an attempt has been made to evaluate the performance of proposed routing strategy in realistic environment. The simulation results shows that the path selection utilising the fuzzy theory presents far better results when compared with shortest path routing protocol employing CR capabilities.

Publicly verifiable watermarking scheme for intellectual property protection using quantum Chaos and bit plane complexity slicing

Intellectual Property such as music, painting, videos and other similar works being broadcasted on web need to be protected against copyright infringement to ensure the rights of their legitimate owners. Moreover, their users must also be sure of the originality of these artefacts. Both these problems can be solved through proper authentication on behalf of the creator. For this purpose, various publicly verifiable watermarking schemes have been available in literature. Recent proposal, in this domain, is based on chaos theory and Secured Hashing Algorithms SHA-2. Due to tremendous growth in the availability of Intellectual Property on the web and associated breaches it becomes a mandatory requirement to update these authenticating schemes. This paper proposes the usage of some more secure, reliable and efficient components in watermarking schemes than being used at present. Proposed changes include the deployment of encryption scheme based on Quantum Logistic maps instead of current Chaos encryption based on peter de-jong map, in order to optimise randomness, correlation and time complexity. For better security and efficiency in hardware implementation SHA-3 is a better choice than SHA-2. Data embedding can be done in regions where imperceptibility is quite high. The proposed changes can result in the creation of more reliable and efficient system. To test the hypothesis, proposed mechanism has been implemented in MATLAB-16a and various performance metrics such as correlation coefficient, PSNR, UIQI, SSIM have been measured. The results show that proposed scheme outperforms its counterpart in terms of all the performance metrics.

An efficient hybrid security mechanism based on chaos and improved BPCS

Commonly used security mechanisms such as cryptography and steganography suffer from weaknesses when used in a standalone manner. Extra efforts in the form of additional permutations/diffusions etc. result in higher ciphering/deciphering time complexity. Thus, there is a requirement for a security mechanism(s) which can provide adequate security without putting a considerable burden on ciphering/deciphering time complexity. This paper is an effort in this direction. The paper proposes a hybrid mechanism that employs chaotic based encryption scheme to encrypt data and an improved Bit-Plane Complexity Segmentation Steganography algorithm to embed the data. The proposed mechanism uses two new complexity measures to differentiate between noisy regions and simple ones appropriately. The scheme was implemented in MATLAB, and the simulation results show that the proposed mechanism has high embedding capacity, high security with a moderate decrease in PSNR value and is computationally fast.