Anonymous Web Browsing with Onion Routing Technology

BME-VIK, Híradástechnika Tanszék

Private electronic communication is becoming an increasingly important public issue. Encryption can effectively hide the content of a conversation. Most security concerns focus on preventing eavesdropping, outsiders listening in on electronic conversations. But encrypted messages can still be tracked, revealing the identity of the communicating parties, without decrypting the secret data payload.

This tracking is called traffic analysis and may reveal sensitive information. The simple fact that two parties are communicating is a source of information, and should be protected. For example, the existence of inter-company collaboration may be confidential. Similarly, e-mail users may not wish to reveal who they are communicating with to the rest of the world. In certain cases anonymity may be desirable also: anonymous e-cash is not very anonymous if the communication channel identifies the purchaser. Web based shopping or browsing of public databases should not require revealing one's identity.

Onion Routing is an infrastructure for providing anonymous connection over a public network. The Onion Routers are actually Chaum-mixes. Onion Routing provides bi-directional and near real-time communication similar to normal TCP/IP socket connections. Onion Routing can be used with applications that are proxy-aware, as well as several non-proxy-aware applications, without modification to the applications. A specialized proxy that removes identifying information from the application layer data stream may make private communication anonymous too.