Book excerpt: According to the national standards Baseline for Classified Protection of Information System Security Technical Requirements of Security Design for Information System Classified Protection, and the characteristics of financial industry and requirements for information systems security development, this Standard has designed the information security system structure in divisions and has specified the application systems depending on the system level, so as to guarantee industrialized and concretized national requirements for classified protection, and to improve the protection level of information security for the important networks and information systems of our bank.