The number of computers infected with malware increases inexorably, year-by-year, both in the commercial and consumer sector. Recent statistics revealed that out of over 18 million computers worldwide scanned for malware, over 50% were infected. With malicious code being practically impossible to eliminate and even contain on the macroscale, the importance of dependability techniques that make critical systems operate correctly despite malicious intrusions is steadily growing.
In this talk we will present both fundamentals and state-of-the-art of intrusion-tolerant, also called Byzantine fault tolerant (BFT) distributed algorithms and systems. In particular, we will focus on techniques for data and state-machine replication which are very often used to boost the dependability of critical distributed services. We will also review the commonly cited impediments to practical deployment of BFT solutions and discuss possible ways to mitigate them in the context of cloud computing.
