With the evolution of new technologies, the growing reliance on networks has increased immensely. Such an advancement induces malicious attacks and software errors to occur frequently. Building robust network services that can tolerate a wide range of failure types is a fundamental problem in distributed systems.
The most fundamental approach, called Byzantine fault tolerance, helps mask arbitrary failures exhibited by failing nodes. Here, the problem of reliably broadcasting messages in a mutli hop network is dealt, where some nodes are likely to fail. Most of the existing solutions require high network connectivity and these requirements become difficult to satisfy when the network grows large.
In this paper, a study on various Byzantine fault tolerant methods has been carried out which has been developed and implemented by research experts in this field. These solutions are particularly customized to adapt to sparsely connected networks. Keywords: Byzantine Failures; Multi hop Network; Asynchronous Network;, Fault Tolerance; Reliable Broadcast; Distributed Computing 1. Introduction In this modern era, the World Wide Web is being used by millions of people on a day-to-day basis for various purposes.
Through the use of a standard web browser, the user can acquire information stored on Web servers situated anywhere on the globe. This results in an illusion that all this information is situated locally on the user’s computer. But in reality, the Web depicts a huge distributed system that occur as a single resource to the user. There are several definitions and outlooks on what distributed systems are. According to Tanenbaum, a distributed system is interpreted as “A group of independent computers that portrays as a single computer to the users of the system” 2. Leslie Lamport’s interpretation of distributed system is postulated as “A distributed system is one in which the failure of a computer you didn’t even know existed can convert your own computer unusable”. A common misapprehension that surrounds the concept of distributed systems is that it is just another label for a network of computers.
However, this neglects an important distinction. A distributed system is one that is built on top of a network and it tries to hide the existence of multiple autonomous computers. A distributed system appears as a single entity providing the user with the services required.
