Replicated services accessed via quorums enable each access to be performed at only a subset (quorum) of the servers and achieve consistency across accesses by requiring any two quorums to intersect. Recently, b-masking quorum systems, whose intersections contain at least 2b+1 servers, have been proposed to construct replicated services tolerant of b-arbitrary (Byzantine) server failures. In th...

We study direct democracy with population uncertainty. Voters’ participation is often among the desiderata by the election designer. A participation quorum is a threshold on the fraction of participating voters below which the status quo is kept. We show that participation quorums produce incentive for partisans of the status quo to abstain, with the consequence that the status quo may be kept ...

The efficient use of the bandwidth allocated for a cellular wireless network is crucial for the satisfactory performance of the system. In order to increase the channel utilization, the channels are allocated to different cells in a dynamic way. The dynamic channel schemes can be categorized in to centralized and distributed. However, the centralized schemes are neither reliable nor scalable. T...

Closed user group based on a Peer-to-Peer system require a membership mechanism that is fully decentralized. Several suggestions have been made in the literature. However, the proposed mechanisms have some significant drawbacks since any peer can easily bypass the proposed membership mechanism. In this paper we present a new fully decentralized and secure membership mechanism for Peer-to-Peer s...

The marine bacterium Vibrio harveyi possesses two quorum sensing systems (System 1 and System 2) that regulate bioluminescence. Although the Vibrio cholerae genome sequence reveals that a V. harveyi-like System 2 exists, it does not predict the existence of a V. harveyi-like System 1 or any obvious quorum sensing-controlled target genes. In this report we identify and characterize the genes enc...

The ExpR/Sin quorum-sensing system of the gram-negative soil bacterium Sinorhizobium meliloti plays an important role in the establishment of symbiosis with its host plant Medicago sativa. A mutant unable to produce autoinducer signal molecules (sinI) is deficient in its ability to invade the host, but paradoxically, a strain lacking the quorum-sensing transcriptional regulator ExpR is as effic...

Probabilistic quorum systems can tolerate a larger fraction of faults than can traditional (strict) quorum systems, while guaranteeing consistency with an arbitrarily high probability for a system with enough replicas. However, they are hampered in that, like strict quorum systems, they allow for Byzantine-faulty servers to collude maximally to provide incorrect values to clients. We present a ...

Vibrio harveyi is amongst the most important bacterial pathogens in aquaculture. Novel methods to control this pathogen are needed since many strains have acquired resistance to antibiotics. We previously showed that quorum sensing-disrupting furanones are able to protect brine shrimp larvae against vibriosis. However, a major problem of these compounds is that they are toxic toward higher orga...

This paper presents robust emulation of multi-writer/multi-reader registers in message-passing systems using dynamic quorum conngurations. In addition to processor and link failures, this emulation tolerates changes in quorum conngurations, i.e., on-line replacements of one quorum system consisting of read and write quorums with another such system. This work extends the results of Attiya, Bar-...