Problem statement: In peer-to-peer networks, Byzantine fault tolerance refers to the capability of a system to tolerate Byzantine faults. It can be achieved by replicating the server and by ensuring all server replicas reach an agreement on the input despite Byzantine faulty replicas and clients. Since malicious attacks and software errors can cause faulty nodes to exhibit Byzantine behavior, B...

Byzantine quorum systems have been proposed that work properly even when up to f replicas fail arbitrarily. However, these systems are not so successful when confronted with Byzantine faulty clients. This paper presents novel protocols that provide atomic semantics despite Byzantine clients. Our protocols are the first to handle all problems caused by Byzantine clients. They prevent Byzantine c...

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The bronze pendant in question the form of a fine shield was discovered south-­western Crimea, vicinity mediaeval Cherson. Its front side depicts holy rider piercing demon with cross; first words Psalm 90 (according to Orthodox Bible numeration) are engraved on back. image horse-­rider spear daemon laying below legs his horse is one most popular apotropaic scenes. It appeared amulets Late Roman...

Attacks where adversaries have full control of a number of authenticated devices and behave arbitrarily to disrupt the network are referred to as Byzantine attacks. Traditional secure routing protocols are vulnerable to this class of attacks since they usually assume that once authenticated, a node can be trusted to execute the protocol correctly. We present a detailed description of several By...

Adding Byzantine tolerance to large scale distributed systems is considered non-practical. The time, message and space requirements are very high. Recently, researches have investigated the broadcast problem in the presence of a f̀ -local Byzantine adversary. The local adversary cannot control more than f̀ neighbors of any given node. This paper proves sufficient conditions as to when the synchro...

This paper investigates the task solvability of mobile robot systems subject to Byzantinefaults. We first consider the gathering problem, which requires all robots to meet in finite timeat a non-predefined location. It is known that the solvability of Byzantine gathering stronglydepends on a number of system attributes, such as synchrony, the number of Byzantine robots,schedulin...

Traditional Byzantine resilient algorithms use 2f+1 vertex disjoint paths to ensure message deliveryin the presence of up to f Byzantine nodes. The question of how these paths are identified is related tothe fundamental problem of topology discovery.Distributed algorithms for topology discovery cope with a never ending task, dealing with frequentchanges in the network topology a...

We introduce a stronger validity property for the byzantine agreement problem with orderable initial values: The median validity property. In particular, the decision value is required to be close to the median of the initial values of the non-byzantine nodes. The proximity to the median scales with the desired level of fault-tolerance: If no fault-tolerance is required, algorithms have to deci...

In this paper, we present a Byzantine fault tolerant distributed commit protocol for transactions running over untrusted networks. The traditional two-phase commit protocol is enhanced by replicating the coordinator and by running a Byzantine agreement algorithm among the coordinator replicas. Our protocol can tolerate Byzantine faults at the coordinator replicas and a subset of malicious fault...