Biblio

Privacy preservation is a challenging task with the huge amount of data that are available in social media. The data those are stored in the distributed environment or in cloud environment need to ensure confidentiality to data. In addition, representing the voluminous data is graph will be convenient to perform keyword search. The proposed work initially reads the data corresponding to social media and converts that into a graph. In order to prevent the data from the active attacks Advanced Encryption Standard algorithm is used to perform graph encryption. Later, search operation is done using two algorithms: kNK keyword search algorithm and top k nearest keyword search algorithm. The first scheme is used to fetch all the data corresponding to the keyword. The second scheme is used to fetch the nearest neighbor. This scheme increases the efficiency of the search process. Here shortest path algorithm is used to find the minimum distance. Now, based on the minimum value the results are produced. The proposed algorithm shows high performance for graph generation and searching and moderate performance for graph encryption.

Information security has become a major challenge in data transmission. Data transmitted through the network is vulnerable to many passive and active attacks. Cryptographic algorithms provide security against the data intruders and provide secure network communication. In this method, two algorithms TEA and DNA are combined to form a new algorithm called DETD (Double Encryption using TEA and DNA). The algorithm mainly deals with encryption and decryption time of a given input text. Here, both the encryption and decryption time are compared with the other two algorithms and the results are recorded. This algorithm also aims to provide data security by increasing the levels of encryption.

Routing security plays an important role in Mobile Ad hoc Networks (MANETs). Despite many attempts to improve its security, the routing procedure of MANETs remains vulnerable to attacks. Existing approaches offer support for detecting attacks or debugging in different routing phases, but many of them have not considered the privacy of the nodes during the anomalies detection, which depend on the central control program or a third party to supervise the whole network. In this paper, we present an approach called LAD which uses the raw logs of routers to construct control a flow graph and find the existing communication rules in MANETs. With the reasoning rules, LAD can detect both active and passive attacks launched during the routing phase. LAD can also protect the privacy of the nodes in the verification phase with the specific Merkle hash tree. Without deploying any special nodes to assist the verification, LAD can detect multiple malicious nodes by itself. To show that our approach can be used to guarantee the security of the MANETs, we deploy our experiment in NS3 as well as the practical router environment. LAD can improve the accuracy rate from 2.28% to 29.22%. The results show that LAD performs limited time and memory usages, high detection and low false positives.

Mobile ad-hoc network (MANET) is a system of wireless mobile nodes that are dynamically self-organized in arbitrary and temporary topologies, that have received increasing interest due to their potential applicability to numerous applications. The deployment of such networks however poses several security challenging issues, due to their lack of fixed communication infrastructure, centralized administration, nodes mobility and dynamic topological changes, which make it susceptible to passive and active attacks such as single and cooperative black hole, sinkhole and eavesdropping attacks. The mentioned attacks mainly disrupt data routing processes by giving false routing information or stealing secrete information by malicious nodes in MANET. Thus, finding safe routing path by avoiding malicious nodes is a genuine challenge. This paper aims at combining the existing cooperative bait detection scheme which uses the baiting procedure to bait malicious nodes into sending fake route reply and then using a reverse tracing operation to detect the malicious nodes, with an RSA encryption technique to encode data packet before transmitting it to the destination to prevent eavesdropper and other malicious nodes from unauthorized read and write on the data packet. The proposed work out performs the existing Cooperative Bait Detection Scheme (CBDS) in terms of packet delivery ratio, network throughput, end to end delay, and the routing overhead.

Routing security has a great importance to the security of Mobile Ad Hoc Networks (MANETs). There are various kinds of attacks when establishing routing path between source and destination. The adversaries attempt to deceive the source node and get the privilege of data transmission. Then they try to launch the malicious behaviors such as passive or active attacks. Due to the characteristics of the MANETs, e.g. dynamic topology, open medium, distributed cooperation, and constrained capability, it is difficult to verify the behavior of nodes and detect malicious nodes without revealing any privacy. In this paper, we present PVad, an approach conducting privacy-preserving verification in the routing discovery phase of MANETs. PVad tries to find the existing communication rules by association rules instead of making the rules. PVad consists of two phases, a reasoning phase deducing the expected log data of the peers, and a verification phase using Merkle Hash Tree to verify the correctness of derived information without revealing any privacy of nodes on expected routing paths. Without deploying any special nodes to assist the verification, PVad can detect multiple malicious nodes by itself. To show our approach can be used to guarantee the security of the MANETs, we conduct our experiments in NS3 as well as the real router environment, and we improved the detection accuracy by 4% on average compared to our former work.