International Association for Cryptologic Research
The hierarchical access control scheme based on Chinese Reminder Theorem based Hierarchical Access Control Scheme (CRTHACS) was supposed to be capable of hiding hierarchical structure, but the researcher showed practical attacks on CRTHACS to reveal the hierarchies it hides. Then, the researcher modified it, and gave a new CRTHACS to resist those attacks. Nevertheless, the authors find that the modified version is still defective if it permits changes of structure, i.e. the scheme works in a dynamic scenario. In this paper, they describe their attack on the modified version of CRTHACS.