| Multi-level key system is widely used in the architecture of modern security systems. The security of subordinate keys in the multi-level key system is guaranteed by superior keys, and the root key is the source of the whole key system. The security of root key is the foundation and guarantee of the security of whole system, and the management of the root key has become the core problem of key management. In some of current mobile communication systems represented by3G system, root key is used in a simple way and cannot be updated safely. Once the root key was revealed, it will inflict considerable losses on the users. Some root key management schemes were proposed based on symmetric cryptosystem, which, however, open up security holes. In wired network, asymmetric security schemes based on PKI are used to ensure the security of e-commerce system. However, it is difficult to apply PKI on wireless communication networks directly due to the high resource requirement using digital certificates. In order to solve the problems above, this paper proposes a root key management scheme based on PKI. The scheme borrows from the PKI security architecture, and reduces the cost by improving the key management processes, which can guarantee that the root key could be updated in a secure way in a resource-constrained wireless communication network.This paper uses PKI technologies to manage the root key of the communication systems and implements a PKI-based root key management system. The root key update process in the system is dynamic and safe. The main work of this paper includes:1. The role of root key in the communication system is studied, the security threats and security requirements in the management of the root key are analyzed.2. A root key management system based on PKI is designed and implemented and related modules including a root key management module are completed. The system performs several key functions, such as root key’s generation, distribution and updating.3. Comparisons between this system and other schemes which based on symmetric cryptography and WPKI are made, and this paper also analyzes the improvements on security and efficiency aspects. |
