Anonymity means that the identity of the user performing a certain action is maintained secret. The protocols for ensuring anonymity often use random mechanisms which can be described probabilistically. In this paper we propose a notion of weak probabilistic anonymity, where weak refers to the fact that some amount of probabilistic information may be revealed by the protocol. This information c...

Anonymity has become a significant issue in security field by recent advances in information technology and internet. The main objective of anonymity is hiding and side a system. Many methods and protocols have been proposed with different anonymity services to provide anonymity requirements in various fields until now. Each anonymity method or protocol is developed using particular approach. I...

Anonymity(key-privacy) as well as security(data-privacy) are all important features in public-key encryption applications. In this paper two new and general concepts, named “relevant anonymity” and “relevant security”, are defined. Based-upon these concepts some general results on anonymity in public-key encryption are proved, which fall in three categories. The first results are two general re...

In the framework of peer to peer distributed systems, the problem of anonymity in structured overlay networks remains a quite elusive one. It is especially unclear how to evaluate and improve sender anonymity, that is, untraceability of the peers who issue messages to other participants in the overlay. In a structured overlay organized as a chordal ring, we have found that a technique originall...

There are many systems that provide anonymity service for the users. Most of these systems work on the separation between the users’ identity and the final destination. The level of anonymity these services provide affected by several factors. Some of these factors are related to the design of the anonymity service itself. Others are related to how the system is used or what is the application/...

Anonymity on the Internet is a property commonly identified with privacy of electronic communications. A number of different systems exist which claim to provide anonymous email and web browsing, but their effectiveness has hardly been evaluated in practice. In this thesis we focus on the anonymity properties of such systems. First, we show how the anonymity of anonymity systems can be quantifi...