With the computerized message systems replacing the physical transport of paper and ink documents, an effective solution for authentication of the electronic data is necessary. In situation where there is not complete trust between sender and receiver, something more than authentication is needed .The most attractive solution to this problem is the digital signature. While the nature of the transaction these documents are meant to support has not changed, the environment in which the transaction is made is changing.  To support the new environment we must provide rules and practices that employ electronic and digital signature technology to achieve and surpass the functionality historically expected from paper based documents with ink signatures. Compared to the tedious and labour-intensive paper methods such as checking specimen signature cards, digital signatures yield a high degree of assurance without adding greatly to the resources required for processing documents.  Digital signatures have been in use for quite a while to authenticate various e-commerce and m-commerce transactions. Today, the processes of creating and verifying a digital signature provide a high level of assurance to the involved parties that the e-signature is genuinely the signer’s, and that the electronic document (or the e-contract) is authentic.

Keywords— Message security, Cryptography, Digital signature.

A vehicular Ad hoc Network (VANET) is emerged as new technology to communicate between vehicles without using infrastructure. The characteristics of VANET are high mobility and rapid change of topology, so the routing protocols affected by the rapid changes and symmetric link break.  This paper evaluates three routing protocols: AODV, OLSR and DYMO, by analyzing the performance of these routing protocols using two different MAC protocols IEEE 802.11p and IEEE 802.11g. As well as, two different scenarios are considered (highway and city) to measure and evaluate the performance of routing protocols by varying the number of vehicles, vehicles speed using OMNeT++ as network simulator Simulation Urban MObility (SUMO) as a traffic simulator. In addition to that, analysis shows that AODV outperform OLSR and DYMO in terms of average throughput. While in term of end-to-end delay, DYMO has the lowest delay.

Keywords— VANET, Routing Protocols, OMNeT++, SUMO, MAC protocols

Cloud computing is the delivery of computing services over the Internet. Cloud services allow the users to use software and hardware that are managed by third parties at remote locations. The characteristics of cloud computing include on demand self service, broad network access, resource pooling, rapid elasticity and measured service. On demand self service means that customers can request and manage their own computing resources. Broad network access allows services to be offered over the Internet or private networks. Cloud services are popular because people can access their e-mail, social networking site or photo service from anywhere in the world, at any time. It does not require any cost.  Cloud computing has the many services, but security is the main issue in cloud computing. In our paper, we are going to use the pattern based security with Diffie-Hellman algorithm. With the help of these algorithms we can make our cloud more secure.

Keywords: Cloud Computing, Security, Pattern based security, Diffie-Hellman algorithm