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Proactive recovery approach for intrusion tolerance with dynamic configuration of physical and virtual replicas

Proactive recovery mechanism has been widely used in building intrusion-tolerant systems that are able to tolerate an arbitrary number of faults. However, previous proactive recovery methods seldom consider the dynamic in attacking power that may cause the increase in fault rate, resulting unguaranteed service availability. This paper describes an approach for tolerating intrusions, or more precisely, damages to replicated data, through dynamic configuration of physical and virtual replicas, which follows a general approach called proactive recovery, and proposes to dynamically adjust recovery frequency to handle potentially changing fault rate. This dynamic proactive recovery method takes the dynamic changes of attaching power into consideration to avoid/minimize the effect of intrusions. Our method is especially effective and useful in intrusion tolerance with physical replicas: it dynamically provides virtual replicas during rejuvenation phase. Copyright © 2012 John Wiley & Sons, Ltd.