Protecting an entity by hiding its role in anonymity networks

Knowing the role of entities in a network undermines anonymity and facilitates the identification of their behavioral patterns. In many existing low-latency anonymity network structures, the creation and use of tunnels for packet transmission allow adversaries to discern the roles of entities. This paper explores the impact of identifying these tunnels, specifically how such identification can expose an entity’s role in relation to a particular message, potentially reducing the level of anonymity in the network. To explore this, we first discuss two key aspects of anonymity networks: the distribution of information and the homogeneity of roles. We then analyze several low-latency anonymity structures to assess vulnerabilities related to tunnel identification, evaluating their strengths and weaknesses based on the aforementioned aspects. In addition, we propose a novel network structure that addresses these vulnerabilities by eliminating the conventional tunnel mechanism, which typically requires a tunnel establishment message. This change prevents adversaries from identifying an entity’s role. In the proposed structure, the sender and intermediate relays work together to select distinct routes for each packet, removing the need for the sender to establish a dedicated data tunnel. To provide a deeper analysis, we will describe in detail the information an attacker can obtain by tracing tunneling messages and how this compromises anonymity by exposing the roles of entities. We will also evaluate how these changes affect the degree of anonymity based on the attacker’s knowledge. Our evaluation shows that the proposed technique effectively eliminates traffic patterns that would normally reveal the roles of entities, thus neutralizing the attacker’s ability to compromise anonymity. As a result, the average level of anonymity is significantly improved compared to previous structures. Overall, our findings suggest that the proposed approach offers a more effective strategy for concealing the roles of entities compared to earlier methods.