Tor is an anonymous communication network. If more users are becoming interested in their privacy, the need for such anonymous services might increase. The second generation onion router design tor and its previous designs seem to have been under research and there have been rather recent papers on tor's vulnerabilities. Various low-latency anonymous communication systems such as tor and anonymizer have been designed to provide anonymity service for users. In order to hide the communication of users, most of the anonymity systems pack the application data into equal-sized cells (e.g., 512 B for tor, a known real-world, circuit-based, low-latency anonymous communication network).