In 2001, two information theoretic anonymity metrics were proposed: the effective anonymity set size and the degree of anonymity. Here, we propose an abstract model for a general anonymity system which is consistent with the definition of anonymity on which the metrics are based. We revisit entropybased anonymity metrics, and we apply them to Crowds, a practical anonymity system. We discuss the...

Since its appearance in 2008, blockchain technology has found multiple uses fields such as banking, supply chain management, and healthcare. One of the most intriguing is voting systems, where can overcome security transparency concerns that plague traditional systems. This paper provides a thorough examination implementation blockchain-based system. The proposed system employs cryptographic me...

We investigate the importance of the social context for people’s voluntary contributions to a national park in Costa Rica, using a natural field experiment. Some subjects make actual contributions while others state their hypothetical contribution. Both the degree of anonymity and provided information about the contributions of others influence subject contributions in the hypothesized directio...

Anonymity has been formalized and some metrics have been defined in the scope of anonymizing communication channels. In this paper, such formalization has been extended to cope with anonymity in those scenarios where users must anonymously prove that they own certain privileges to perform remote transactions. In these types of scenarios, the authorization policy states the privileges required t...

We present a protocol for anonymous communication over the Internet. Our protocol, called P 5 (Peer-to-Peer Personal Privacy Protocol) provides sender-, receiver-, and sender-receiver anonymity. P 5 is designed to be implemented over the current Internet protocols, and does not require any special infrastructure support. A novel feature of P is that it allows individual participants to trade-of...

We present a protocol for anonymous communication over the Internet. Our protocol, called P5 (Peerto-Peer Personal Privacy Protocol) provides sender-, receiver-, and sender-receiver anonymity. P5 is designed to be implemented over the current Internet protocols, and does not require any special infrastructure support. A novel feature of P5 is that it allows individual participants to trade-off ...

Ensuring anonymity in sensor networks is a major security goal. Using traffic analysis, the attacker can compromise the network functionality by correlating data flow patterns to event locations/active areas. In this paper we present a novel hierarchical anonymous communication protocol that hides the location of nodes and obscure the correlation between event zones and data flow from snooping ...

We examine experimentally how a person’s generosity depends on the degree of anonymity between giver and recipient, as well as on the parties’ sexes. Less is given when the giver is paid on stage rather than in private; men receive less than women; fewer men than women give non-zero amounts. The results suggest that it may be problematic to organize experimental data in terms of social distance...

The ability to perform meaningful empirical studies is of essence in research in spatio-temporal query processing. Such studies are often necessary to gain detailed insight into the functional and performance characteristics of proposals for new query processing techniques. We present a collection of spatio-temporal data, collected during an intelligent speed adaptation project, termed INFATI, ...

This paper introduces an information theoretic model that allows to quantify the degree of anonymity provided by schemes for anonymous connections. It considers attackers that obtain probabilistic information about users. The degree is based on the probabilities an attacker, after observing the system, assigns to the different users of the system as being the originators of a message. As a proo...