Internet technologies bring with them a host of ramifications for the personal user, including a threat to personal privacy and anonymity. Anonymity and privacy are very closely integrated. Anonymity can be regarded as a way to protect one’s privacy. Third parties, providing Internet services, can record and collect user data in order to create user profiles. This is done in numerous ways, such...

In electronic anonymity markets a taker seeks a specified number of market makers in order to anonymize a transaction or activity. This process requires both coalition formation, in order to create an anonymity set among the taker and makers, and the derivation of the fee that the taker pays each maker. The process has a novel property in that the taker pays for anonymity but anonymity is creat...

Most electronic cash systems in the literature have been developed in the single bank model in which clients and merchants have accounts at the same bank. In the real world, electronic cash may be issued by a large group of banks, monitored by the Central Bank. Thus not only client anonymity but also bank anonymity should be considered to simulate anonymity of real money. Because anonymity coul...

This work presents RPM, a scalable anonymous communication protocol suite using secure multiparty computation (MPC) with the offline-online model. We generate random, unknown permutation matrices in secret-shared fashion and achieve improved (online) performance lightest overhead for clients compared to state of art robust protocols. Using square-lattice shuffling, we make our scale well as num...

Existing privacy regulations together with large amounts of available data created a huge interest in data privacy research. A main research direction is built around the k-anonymity property. Several shortcomings of the k-anonymity model were addressed by new privacy models such as p-sensitive k-anonymity, l-diversity, (α,k)-anonymity, t-closeness. In this chapter we describe two algorithms (G...

Anonymous message transmission systems are the building blocks of several high-level anonymity services (e.g. epayment, e-voting). Therefore, it is essential to give a theoretically based but also practically usable objective numerical measure for the provided level of anonymity. In this paper two entropybased anonymity measures will be analyzed and some shortcomings of these methods will be hi...

k-Anonymity is a privacy model requiring that all combinations of key attributes in a database be repeated at least for k records. It has been shown that k-anonymity alone does not always ensure privacy. A number of sophistications of k-anonymity have been proposed, like p-sensitive k-anonymity, l-diversity and t-closeness. We identify some shortcomings of those models and propose a new model c...

In this paper, we present a concise formal definition of anonymity for voting protocols using process algebra Communicating Sequential Processes (CSP). We analyse a number of anonymity definitions and give the formal definitions for the strong and weak anonymity highlighting the difference between them. It shows us that the strong anonymity definition is not an appropriate definition as it is t...

Privacy is a value shared by most human societies. The work presented here is inspired by this value and is concerned with methods by which it may be achieved. In a world where we increasingly make use of information systems amenable to surveillance, privacy is no longer an inherent assumption; it has becomes a property that must be explicitly designed. In this thesis we examine the background ...