Anonymity in an electronic society: A survey

In the wake of surveillance scandals in recent years, as well of the continuous deployment of more sophisticated censorship mechanisms, concerns over anonymity and privacy on the Internet are ever growing. In the last decades, researchers have designed and proposed several algorithms and solutions that allow interested parties to maintain anonymity online, even against powerful opponents. In this chapter, we present a survey of the classical anonymity schemes that proved to be most successful, describing how they work and their main shortcomings. Finally, we discuss new directions in Anonymous Communication Networks (ACN) taking advantage of today's services, like On-Line Social Networks (OSN). OSN offer a vast pool of participants, allowing to effectively disguise traffic in the high volume of daily communications, thus offering high levels of anonymity and good resistance to analysis techniques.