International Journal of Computer Applications (0975 – 8887) Volume 121 – No.23, July 2015 12 Anonymous Communication System based on Onion Routing Manish Dhankani B.E. Comp Engineering VES Institute of Technology Abhishek Dhameja B.E. Comp Engineering VES Institute of Technology Surendrakumar Darda B.E. Comp Engineering VES Institute of Technology Dimple Bohra Comp Engineering Dept. VES Institute of Technology ABSTRACT Communication is one of the most important medium through which people can share their intellectual and cultural beliefs. Communication with the help of computers is increasing at a rapid speed. Securing this communication is of prime importance to maintain user privacy and data confidentiality. Anonymous communication systems can help us to prevent from eavesdropping and other attacks. Anonymous communication based on Onion Routing helps us to build a system that not only secures the data using multiple layers encryption but also by hiding the true sender and receiver of the data. Though there are many alternative solutions, Onion routing provides the efficient way of protection, which we have implemented. Keywords Onion Routing, Anonymous Communication System, AES Algorithm, File Transfer Protocol, Encryption, Decryption. 1. INTRODUCTION Onion routing is the technique in which the information is exchanged between sender and the receiver anonymously via a number of intermediate routers known as onion routers. Instead of establishing a minimum distance route, a random path between the sender and receiver with random number of intermediate nodes i.e. the onion routers is used for data transfer. Onion routing technique also secures the communication using multiple layers encryption. Every node has knowledge about only is previous and next router. In this way the router has no idea about the sender and receiver of the data. Also every node is assigned a key before the communication starts which is used to decrypt the outermost layer of encryption and then passes it on to the next node. Thus only the last node can access the contents of the data packet [5]. The Figure 1 explains onion routing in a more concise way. Figure 1: Basis of Onion Routing 2. CURRENT ANONYMITY SYSTEM There are several communication systems present that provide anonymous communication. The different anonymity systems are Mix Networks, Low-Latency communication and Data publishing. The former has high latency, message oriented and can be in either one-way or two-ways. Few examples of this type are MixMaster, MixMinion, etc. The Low-Latency anonymity system include TOR(The Onion Router),JAP, Anonymous proxies and so on [4]. The latter type comprises of FreeNet, and is different from most other peer-to-peer applications, both in how users interact with it and in the security it offers. Freenet separates the underlying network structure & protocol from how users communicate with network. The contents on Freenet can be accessed in various ways and the simplest of them is using FProxy. FProxy allows users to browse free sites. For most of configuration & node management tasks, web interface is generally used. Freenet provides the opennet and daknet, two different levels of security [6]. 3. PROPOSED SYSTEM It follows three-tier architecture with, 1. Application: it consists of Onion Routing application which is to be installed on every node. 2. Server: it comprises of web server, encryption keys, maintain and update information of online nodes, generate paths and choose a random path. 3. Data tier: it consists table of online nodes and encryption keys. Figure 2: Conceptual Design