Among all classes of faults, Byzantine faults form the most general modeling of value faults. Traditionally, in the Byzantine fault model, faults are statically attributed to a set of up to t processes. This, however, implies that in this model a process at which a value fault occurs is forever “stigmatized” as being Byzantine, an assumption that might not be acceptable for long-lived systems, ...

The relevance of Byzantine fault tolerance in the context of cloud computing has been questioned[3]. While arguments against Byzantine fault tolerance seemingly makes sense in the context of a singlecloud, i.e., a large-scale cloud infrastructure that resides under control of a single, typically commercialprovider, these arguments are less obvious in a broader context of the Int...

This paper presents several fault-tolerant simulations of a single-writer multi-reader regular register in storage systems. One simulation tolerates fail-stop failures of storage servers and require a majority of nonfaulty servers, while the other simulation tolerates Byzantine failures and requires that two-thirds of the servers to be nonfaulty. A construction of Afek et al. [2] is used to mas...

This paper describes the design, implementation and usage of a secure scalable Byzantine fault tolerant MDS system in the Grid. The scalable Byzantine fault tolerant MDS system provides a hierarchy GIIS servers, a local GIIS domain can require the resource it needs from remote GIIS domain. By using the statemachine replication approach and quorum system technique, the scalable Byzantine fault t...

This paper presents a new resilience optimal Byzantine consensus algorithm targeting consortium blockchains. To this end, it first revisits the consensus validity property by requiring that the decided value satisfies a predefined predicate, which does not systematically exclude a value proposed only by Byzantine processes, thereby generalizing the validity properties found in the literature. T...

In this paper we present for the first time, the development of a new system for the off-line optical recognition of the characters used in the Orthodox Hellenic Byzantine Music Notation, that has been established since 1814. We describe the structure of the new system and propose algorithms for the recognition of the 71 distinct character classes, based on Wavelets, 4-projections and other str...

We consider here the Byzantine Agreement problem (BA) in synchronous systems with homonyms in the case where some identifiers may be forgeable. More precisely, the n processes share a set of l (1 ≤ l ≤ n) identifiers. Assuming that at most t processes may be Byzantine and at most k (t ≤ k ≤ l) of these identifiers are forgeable in the sense that any Byzantine process can falsely use them, we pr...

Cloud computing is an internet based computing which enables sharing of services. It is very challenging part to keep safely all required data that are needed in many applications for user in cloud. Storing our data in cloud may not be fully trustworthy. Since client doesn’t have copy of all stored data, he has to depend on Cloud Service Provider. This work studies the problem of ensuring the i...

In this paper, we show that the protocol complex of a Byzantine synchronous system can remain (k− 1)-connected for up to ⌈t/k⌉ rounds, where t is the maximum number of Byzantine processes, and t ≥ k ≥ 1. Protocol complex connectivity is important since a (k − 1)-connected protocol complex does not admit solutions for the k-set agreement problem. In crash-failure systems, the connectivity upper ...

The common approach to masking Byzantine failures is by replicating the computation and running a Byzantine agreement protocol among all replicas. However, Byzantine agreement incurs high communication overhead and also requires the use of at least 3f + 1 replicas in order to overcome f such failures. However, for many applications, and in particular scientific computation, it is possible to ac...