One way to camouflage communication over a public network is to mingle connections from a variety of users and applications to make them difficult to distinguish.
David M. Goldschlag, Michael Reed, Paul F. Syverson · 1999
reserving privacy meansnot only hiding the content ofmessages, but alsohiding who istalking towhom (traf-fic analy-sis). Muchlike a physi-cal envelope,the simple application ofcryptography within apacket-switched networkhides the contents of mes-sages being sent, but can revealwho is talking to whom, andhow often. Onion Routing is a gen-eral-purpose infrastructure for privatecommunication over a public network [3, 4, 6].It provides anonymous connections that arestrongly resistant to both eavesdropping andtraffic analysis. The connections are bidirec-tional, near real-time, and can be used for bothconnection-based and connectionless traffic.Onion Routing interfaces with off-the-shelf application software and sys-tems through specialized proxies,making it easy to integrate intoexisting systems. Prototypeshave been running since July1997. At press time, theprototype network is pro-cessing more than one mil-lion Web connections permonth from more than sixthousand IP addresses intwenty countries and in all sixmain top level domains.