Identification of Writing on Bulletin Board via Tor

Abstract

In recent years, awareness of protection of personal information has been increased, and anonymous communication that enables communication with hiding personal information attracts attention. Tor (The Onion Router) realizes anonymous communication most widely, but this anonymization is used for crime. This paper aims to identify users who maliciously write to the Internet bulletin board using Tor. This paper proposes a method of detecting Tor packet of writing on bulletin board. This method captures Tor packets and decides whether the packets is used for writing on bulletin board by using fingerprint. This paper implements the method and experiments to evaluates the method. The result of experiments shows that identification of writing on bulletin websites which use usual CGI programs is not successful at high probability and that modifying CGI programs is useful for identification of writing on bulletin websites. The result also shows that identification of writing on bulletin websites is difficult if users write on bulletin websites and access other websites such as streaming websites.