Boosting Multimode Ruling in DHR Architecture With Metamorphic Relations

ABSTRACT The DHR architecture provides a revolutionary security defense structure for cyberspace. The multimode ruling in DHR is expected to alleviate the oracle problem, which still suffers from the existence of common model vulnerability. In this work, we design a test segmentation method to transform multimode ruling to a metamorphic testing problem. The text test input that causes inconsistency of heterogeneous executors is converted to a condition set, and we extract subsets of conditions based on its syntax tree. The original test can exploit a specific vulnerability, the follow‐up tests are composed by different subsets of conditions within the original test. We collect the execution matrix for the follow‐up tests to analyse the impact of each subset of conditions on ruling decision. Metamorphic relations are extracted based on the localization of independent condition, that is, the subsets of conditions that can impact ruling decision independently. The executors in an inconsistent ruling should be examined with metamorphic testing methods, rather than traditional majority voting mechanism. The proposed test segmentation and improved multimode ruling methods are evaluated on two DHR‐based cases, SQL injection in cyber‐range system and deserialization attack in ‐ project. The experimental results show that our test segmentation can help to locate malicious expressions and the metamorphic testing‐based multimode ruling can generate more correct results than majority voting mechanism with an average 15.8% performance loss.