Designing and Implementing a Diversity Policy for Intrusion-Tolerant Systems

Abstract

SUMMARYResearch on intrusion-tolerant systems (ITSs) is being conducted to protect critical systems which provide useful information services. To provide services reliably, these critical systems must not have even a single point of failure (SPOF). Therefore, most ITSs employ redundant components to eliminate the SPOF problem and improve system reliability. However, systems that include identical components have common vulnerabilities that can be exploited to attack the servers. Attackers prefer to exploit these common vulnerabilities rather than general vulnerabilities because the former might provide an opportunity to compromise several servers. In this study, we analyze software vulnerability data from the National Vulnerability Database (NVD). Based on the analysis results, we present a scheme that finds software combinations that minimize the risk of common vulnerabilities. We implement this scheme with CSIM20, and simulation results prove that the proposed scheme is appropriate for a recovery-based intrusion tolerant architecture.

Duo: Software Defined Intrusion Tolerant System Using Dual Cluster

“…By letting exposure time of a group of container servers much shorter than that of the other, we are able to reduce the overall exposure time of the entire system. Existing ITS architectures assign all the VM servers uniform exposure time without addressing how they select exposure time [8,11,12,16,27,28]. However, we argue that the overall exposure time can be reduced without using additional resources if we assign each server unidentical exposure time in accordance with the type of clients that the server will handle.…”

“…In other words, a TC in the grace period state cannot be selected: rank = state * ( * nearness + (1 − ) * busyness) . (8) In order to select the most appropriate TC, the algorithm first computes ranking values for each TC, which is presented in (8). There are three variables: state, nearness, and busyness.…”

“…Technically, the recovery-based ITS can effectively reduce attack surfaces of the servers [8] by making the servers available to the public including any potential adversaries for a very short period of time and restoring possibly compromised servers. Such a time period is referred to as exposure time, and it plays an extremely crucial role in recovery-based ITS [7,9,10] The exposure time in recovery-based ITS creates a tradeoff between the cost and security.…”

“…The previous studies have only focused on reducing attack surfaces of target servers [8,11] or efficiently recovering target servers [12,13]. Indeed, they have pointed out that finding the best exposure time for ITS is a critical problem that must be solved, but this problem has never been clearly addressed.…”

A Diversity Metric Based Study on the Correlation between Diversity and Security

“…With different working schemes, software diversity can be used to construct the diversified system. A diversified system is an information system consisting of redundant and heterogeneous components, which works according to a voting scheme or dynamic strategy, such as an intrusion tolerant system [6] or an MTD (Moving Target Defense) system [7]. The diversified system is different from the normal static and single-node system because there are redundant functionequivalent components which have made diversity a feature for the whole diversified system.…”