Over the last several decades, there have been numerous systems proposed which aim to preserve the anonymity of the recipient of some data. Some have involved trusted third-parties or trusted hardware; others have been constructed on top of link-layer anonymity systems or mix networks. In this paper, we examine the Pynchon Gate [34], a pseudonymous message system which takes an alternate approa...

Detection and mitigation of Byzantine behaviors in a decentralized learning setting is daunting task, especially when the data distribution at users heterogeneous. As our main contribution, we propose Basil, fast computationally efficient robust algorithm for training systems, which leverages novel sequential, memory assisted performance-based criteria over logical ring while filtering users. I...

We present Moving Participants Turtle Consensus (MPTC), an asynchronous consensus protocol for crash and Byzantine-tolerant distributed systems. MPTC uses various moving target defense strategies to tolerate certain Denial-of-Service (DoS) attacks issued by an adversary capable of compromising a bounded portion of the system. MPTC supports on the fly reconfiguration of the consensus strategy as...

Recent years we have witnessed the emergence of Shared Sensor Networks (SSNs) as a core component of cyber-physical systems for diverse applications. As Wireless Sensor and Actuator Networks (WSANs) design starts shifting from application-specific platforms to shared system infrastructures, a new but pressing research challenge is security. In scenarios involving unprotected hostile outdoor are...

This paper presents the first architecture for large-scale, wide-area intrusion-tolerant state machine replication that is specifically designed to perform well even when some of the servers are Byzantine. The architecture is hierarchical and runs attack-resilient state machine replication protocols within and among the wide-area sites. Given the constraints of the wide-area environment, we exp...

The present document is essentially a summarized version of the dissertation that will be developed within the scope of an MSc degree in Communication Networks, in the area of security in wireless ad hoc network. Wireless ad hoc networking is a technology that allows fast, easy, and inexpensive network deployment. Unfortunately, these advantages also make the task of an attacker simpler, as it ...

The rapid growth of wireless applications has increases the importance for efficient utilization of the scarce spectrum resources. Cognitive Radio Network (CRN) is an emerging technology which leads to solve these problems through dynamic utilization of the unused licensed spectrum. Spectrum sensing is a key function of cognitive radio to find the spectrum holes and Collaborative or cooperative...

A deniable authentication protocol allows a sender to transfer an authenticated message to a receiver, and the receiver cannot prove to a third party about the source of the message. In 2006, Zhu et al. analyzed deniable authentication protocols proposed by Deng et al. in 2001, which were based on a protocol proposed by Aumann et al. in 1998. In this paper, we show that the modified protocols b...