Self-adaptive Anonymous Communication Scheme Under SDN Architecture

Communication privacy and latency perceived by users have become great concerns for delay-sensitive Internet services. Existing anonymous communication systems either provide high anonymity at an expense of prolonged latency(e.g., mix-net), or offer better real-time performance by sacrificing the ability against traffic analysis attacks(e.g., Onion Routing). The emerging Software-Defined Networking(SDN) introduces additional challenges to communication anonymity, due to the existence of a centralized controller that has a global view of the entire network traffic and the ability of performing global traffic analysis attacks to low-latency anonymous communication systems.To address the challenges above, this paper aims to protect communication privacy and reduce the end-to-end latency simultaneously for delay-sensitive services under SDN scenarios. The main contributions of this paper are summarized as follows:1. We propose a new anonymous communication scheme for delay-sensitive services under SDN scenarios benefited from the notion of Mix-nets and random walking strategy, which can simultaneously protect communication privacy and reduce the end-to-end latency.2. A self-adaptive method based on the mix-net framework is designed to dynamically modify the waiting thresholds of mix nodes, which helps to reduce the communication latency, and allows users to assign personalized settings of the thresholds.3. Both theoretical analysis and experimental results prove that our scheme provides a moderate degree of anonymity and effectively reduces the latency derived from mix-net by up to 50%.