Cryptanalysis and improvement of a hierarchical key management scheme foraccess control in the mobile agent

Recently, Chung et al. proposed a new scheme which is based on thepolynomial interpolation formula. In this paper, we will demonstrate twosecurity leaks inherent in Chung et al. 's scheme that : (i) a malicions hostcan access unanthorized confidential files if it has the same confidentialfile(s) with other visited host(s). (ii) a malicious host can accessunanthorized confidential files by comparing the old with the new polynomials,which are owned by other host. That is, Chung et al. 's scheme cannot achievetheir claimed security requirements. Finally, we improve the Chung et al. 'sscheme to counter the proposed attacks and achieve the security requirements ofa key management scheme. ICIC International