Security model research and design based on separate storage of keys

Important data are usually encrypted and stored separately with key. It requires high security. A security model, which is based on security need of data and analysis on design points of excellent encryption software, was proposed for encryption software. This model considers users, encryption platform, key device, and encrypted data as a whole, establishes mutual security relations of the four elements, constructs systemic security relations for the process of encryption, solves security problem of separately stored key.