This paper introduces a permutation generation mechanism based on a shared secret key. The generated permutation vectors are used as encryption keys in a stream ciphering cryptosystem. We investigated various types of attacks on the known stream cipher RC4 and patched most of its loopholes, especially biased-byte and state-related attacks. Unique to our approach, we prove mathematically that the complexity of brute-forcing such a system is (2n), where n is the key size in bytes. This paper also presents a complete security model using permutation-based encryption, in order to handle privacy. In addition, our approach achieved higher performance than that of existing peer techniques, while maintaining solid security. Experimental results show that our system is much faster than the existing security mechanisms, such as AES and DES.

In the today's fast growing world, use of internet is increasing popularly and at the same time Location-based services (LBS) are also getting more popular. LBS providers require user's current locations to answer their location-based queries. The primary objective of the present work is to develop a system which preserves the location privacy of the concerned individual. This objective is achieved by simulating locally cloak algorithm and globally cloak algorithm for Manhattan mobility model and Waypoint mobility model using NS-2.34 environment. In the experiments, to hide the user's current locations in rectangle [bounding box] according to users privacy need, obfuscation and k-anonymity strategies are used.

A MANET is an interconnection of mobile devices by wireless links forming a dynamic topology without much physical network infrastructure such as routers, servers, access points/cables or centralized administration. The multipath routing protocols establish efficient communication within the network by discovering multiple routes between a pair of source and destination in order to have load balancing to satisfy Quality of Service (QoS) requirements. In this paper, the performance comparison and evaluation of the widely used multipath routing protocols such as AOMDV, OLSR and ZRP are carried out in terms of five scenario patterns such as RWM, RPGM, MGM, GMM, and PM in two different traffic patterns such as CBR and TCP using NS2 and Bonn Motion. These multipath routing protocols have been selected for simulation due to their edges over other protocols in various aspects.

Mobile nodes are organized randomly without any access point in Mobile Ad hoc Networks (MANETs). Due to the mobility of nodes, the network congestion occurs. So many congestion control mechanisms were proposed to avoid the congestion avoidance or reducing the congestion status. In this research work, we proposed to develop the Effective Congestion Avoidance Scheme (ECAS), which consists of congestion monitoring, effective routing establishment and congestionless based routing. The overall congestion status is measured in congestion monitoring. In routing establishment, we propose the contention metric in the particular channel in terms of, queue length of packet, overall congestion standard, packet loss rate and packet dropping ratio to monitor the congestion status. Based on the congestion standard, the congestionless based routing is established to reduce the packet loss, high overhead, long delay in the network. By extensive simulation, the proposed scheme achieves better throughput, packet delivery ratio, low end-to-end delay and overhead than the existing schemes.

In this paper, presents an optimized combinational logic based Rijndael S-Box implementation for the SubByte transformation(S-box) in the Advanced Encryption Standard (AES) algorithm on FPGA. S-box dominated the hardware complexity of the AES cryptographic module thus we implement its mathematic equations based on optimized and combinational logic circuits until dynamic power consumption reduced. The complete data path of the S-box algorithm is simulated as a net list of AND, OR, NOT and XOR logic gates, also for increase in speed and maximum operation frequency used 4-stage pipeline in proposed method. The proposed implemented combinational logic based S-box have been successfully synthesized and implemented using Xilinx ISE V7.1 and Virtex IV FPGA to target device Xc4vf100. Power is analized using Xilinx XPower analyzer and achieved power consumption is 29 mW in clock frequency of 100 MHz. The results from the Place and Route report indicate that maximum clock frequency is 209.617 MHz.

With the ever increasing volume of information over wireless medium, security has assumed an important dimension. The security of transmitted data over a wireless channel aims at protecting the data from unauthorized intrusion. Wireless network security is achieved using cryptographic primitives. Some properties that give encryption mechanism their cryptographic strength also make them very sensitive to channel error as well. Therefore, security for data transmission over wireless channel results in throughput loss. Tradeoff between security and throughput is always a major concern in wireless networks. In this paper, a Link Adaptive Encryption scheme is evaluated that adapts to channel variations and enhances the security level of WLANs without making any compromise with the network performance. Numerical results obtained through simulation for link adaptive encryption scheme are compared with the fixed block length encryption technique operating in Cipher Block Chaining (CBC) mode of operation. Optimal block length is also computed, which is assumed to be the effective strength of the cipher. It has been observed that security attained with link adaptive scheme operating in CBC mode is a better solution for security and throughput tradeoff.

The Wireless Sensor Networks are energy constrained and are normally low cost and low power devices. These nodes are deployed over a specific area for specific goals. Due to energy and memory constraints, secure communication among these sensors is challenging management issue. In order to ensure security, proper connectivity among nodes and resilience against node capture, we propose a scheme called as Random Pre-Key distribution scheme which takes advantage of the binomial key pattern while creating and distributing keys. The value of keys would develop the number of patterns, which is given by the binomial distribution, which would be helpful in maintaining a key pool which is all though random in nature and following a pattern leads to more probability of network connection links. This paper provides a secured communication in WSNs environment and pairing user authentication has been proposed. We employ the idea of dividing the sensor network field into scattered nodes. Inside the scenario, one of the sensor nodes is selected as a server sensor node which is responsible for delivering the key. The novelty of the proposed scenario lies behind the idea of incorporating the sensor nodes along with the proper user authentications. We calculate the throughput involving a periodic traffic and obtained results from the xgraph utility with the use of Network Simulator. The results of this key scheme are obtained and show that improvement in terms of connectivity.

Anonymous credential systems permit the users to authenticate themselves in a privacy-preserving way. An anonymous credential system is of major practical relevance because it is the best means of providing privacy for users. In this paper, we propose a technique known as Blacklistable Anonymous Credentials with Trust Reputation (BLACTR) for revoking misbehaving users with Trusted Third Party (TTP). The technique uses both Certifying Authority (CA) review as well as other user reviews in order to blacklist a user making use of the fuzzy and rule matched to check if the person is to be blacklisted or not. The proposed technique performed well when compared to BLAC and BLACR.