Date Added: Jul 2010
Byzantine Fault Tolerant (BFT) protocols are replication-based solutions to the problem of tolerating the arbitrary failures of software and hardware components. The essential assumption for replication is independence of failures. In this paper, the authors categorize four different failure independence levels that could be obtained from the cloud. Providing more level of independence comes with the cost of more delays and less bandwidth, and not a single BFT protocol fits all these deployment setups. Using experimental results, they discuss the possible appropriate BFT protocol for each category.