Existing model poisoning attacks on federated learning (FL) assume that an adversary has access to the full data distribution. In reality, usually limited prior knowledge about clients' data. A poorly chosen target class renders attack less effective. This work considers a semi-targeted situation where source is predetermined but not. The goal cause misclassification of global classifier from c...

Both reliable detection of the primary signal in a noisy and fading environment and nullifying the effect of unauthorized users are important tasks in cognitive radio networks. To address these issues, we consider a cooperative spectrum sensing approach where each user is assigned nonuniform reliability based on the sensing performance. Users with poor channel or faulty sensor are assigned low ...

Mobile ad hoc networks (MANETs) are wireless networks consisting of number of autonomous mobile devices temporarily interconnected into a network by wireless media. MANETs become one of the most prevalent areas of research in the recent years. Resource limitations, energy efficiency, scalability, and security are the great challenging issues in MANETs. Due to its deployment nature, MANETs are m...

The reign of the Doukas dynasty in 1059–1078 was a time when new threats to Byzantine Empire emerge Europe and Asia. One them increased activity Turkmen who were penetrating lands belonging Byzantines. A manifestation these visible during rule Constantine X (1059–1067) 1064. We have there an invasion tribe Uzes, crossed Danube. They ventured so far, as vicinity Thessalonica province Hellas, plu...

With the rapid development of sophisticated attack techniques, individual security systems which base all of their decisions and actions of attack prevention and response on their own observations and knowledge become incompetent. To cope with this problem, collaborative security that coordinates security entities to perform specific security actions is proposed and developed in literature. In ...

Wireless Sensor Networks (WSNs) are susceptible to Sybil attacks in which malicious node creates a huge number of fake identities in order to gain an excessively high advantage through a Byzantine method. A Sybil node using only one physical device may generate random number of additional node identities and can be used to disrupt normal functioning of the WSN, such as multipath routing which i...

Gathering a group of mobile agents is a fundamental task in the field of distributed and mobile systems. This can be made drastically more difficult to achieve when some agents are subject to faults, especially the Byzantine ones that are known as being the worst faults to handle. In this paper we study, from a deterministic point of view, the task of Byzantine gathering in a network modeled as...

This short paper presents a necessary condition for Byzantine k-set agreement in (synchronous or asynchronous) message-passing systems and asynchronous shared memory systems where the processes communicate through atomic single-writer multi-reader registers. It gives a proof, which is particularly simple, that k-set agreement cannot be solved t-resiliently in an n-process system when n ≤ 2t + t...

So far, the distributed computing community has either assumed that all the processes of a distributed system have distinct identifiers or, more rarely, that the processes are anonymous and have no identifiers. These are two extremes of the same general model: namely, n processes use l different identifiers, where 1 ≤ l ≤ n. We call this model homonymous model. To determine the power of homonym...

We study the fundamental Byzantine leader election problem in dynamic networks where the topology can change from round to round and nodes can also experience heavy churn (i.e., nodes can join and leave the network continuously over time). We assume the full information model where the Byzantine nodes have complete knowledge about the entire state of the network at every round (including random...