A security architecture using secret key algorithm and vertical authentication mode is proposed. Establish security protocols in the chip of smart key at network client or mobile phone, and establish key exchange protocol in the chip of encryption cards at network key management center. A combined key real-time generation algorithm is used to solve the update and management problems. Online or offline authentication and documents encryption transmission protocols are adopted to achieve credible connection between users. Accordingly, set up security layer over Internet, which provides convenient encryption ability to each network user, and build credible and secure network system.