How to Tolerate Half Less One Byzantine Nodes in Practical Distributed System

• Autor(a) principal: Correia, Miguel
• Data de Publicação: 2004
• Outros Autores: Neves, Nuno Ferreira, Veríssimo, Paulo
• Tipo de documento: Relatório
• Idioma: por
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10451/14229

The application of dependability concepts and approaches to the design of secure distributed systems is raising a considerable amount of interest in both communities under the designation of intrusion tolerance. However, practical intrusion-tolerant replicated systems based on the state machine approach can handle at most f Byzantine components out of a total of n=3f+1, which is the maximum resilience in asynchronous systems. This paper extends the normal asynchronous system with a special distributed oracle called TTCB. Using this extended system we manage to implement an intrusion-tolerant service, based on the state machine approach (SMA), with 2f+1 replicas only. Albeit a few other papers in the literature present intrusion-tolerant services based on the SMA, this is the first time the number of replicas is reduced from 3f+1 to 2f+1. Another interesting characteristic of the described service is a low time complexity