Confidential paper (also known as security paper, anti-leakage paper, security paper, metal wire paper, anti-theft paper, magnetic fiber paper, confidential paper) is a kind of paper with security functions, mainly used to protect sensitive or confidential information from illegal dissemination. The paper is not significantly different from ordinary paper in appearance, and the security paper has a built-in magnetic fiber, which will trigger an alarm when passing through the security gate, increasing the security of paper information. The role of confidential paper is to prevent information from being leaked in paper form. In confidential fields, such as scientific research and development centers, confidential paper is widely used to store and transmit sensitive information. When documents or materials carrying security paper are illegally taken out of the designated security area, special elements in the security paper will trigger the security equipment to send an alarm, so as to prevent the leakage of information in time.