Time-Bound Key Management Scheme for Secure Broadcasting Using ECC

In this paper, the data to be securely broadcast, for example, electronic newspapers can be organized as a hierarchical tree and encrypted using algorithms according to predefined time periods and user privileges. An efficient key management scheme must achieve hierarchical and time-bound access. The hierarchical property is defined as that the users in the higher class can retrieve the data content that a lower class is authorized to access, but not vice versa. The time-bound property is defined as that the users can access data only in assigned time periods. Elliptic curve cryptography is deployed in this scheme. Intractability of Elliptic Curve Discrete Logarithm Problem (ECDLP) is used to achieve the hierarchical property. This scheme provides security against the collusion attack and reduces space and time complexity. In addition to security and efficiency, flexibility is also achieved in this scheme, thereby providing an efficient key management scheme for secure broadcasting.