Crowds

Crowds is a proposed anonymity network that gives probable innocence in the face of a large number of attackers. Crowds was designed by Michael K. Reiter and Aviel D. Rubin and defends against internal attackers and a corrupt receiver, but provides no anonymity against a global attacker or a local eavesdropper (see "Crowds: Anonymity For Web Transactions"). Crowds is vulnerable to the predecessor attack; this was discussed in Reiter and Rubin's paper and further expanded in "The Predecessor Attack: An Analysis of a Threat to Anonymous Communications Systems" by Matthew K. Wright, Micah Adler, And Brian Neil Levine. Crowds introduced the concept of users blending into a crowd of computers. Provide users with a mechanism for anonymous Web browsing. The main idea behind Crowds anonymity protocol is to hide each user's communications by routing them randomly within a group of similar users. By Crowds protocol a corrupt group member or local eavesdropper that observes a message being sent by a particular user can never be sure whether the user is the actual sender, or is simply routing another user's message.