Secure key management scheme for hierarchical access control based on ECC

In a key management scheme for hierarchical access control, each higher security class can derive the cryptographic keys of his lower security classes. In 2006, Jang and Wang proposed an efficient key management scheme based on elliptic curve cryptosystems. This paper, however, will demonstrate a compromising attack on Jang-Wang scheme to show that the secret keys of some security classes will be compromised. This paper further proposed an improvement to eliminate the pointed out security leak.