Can you steal secrets even with zero contact? In today's world, with highly developed information technology, the invisible electromagnetic figure is everywhere, from mobile phone signals to television broadcasts, from Wi Fi to Bluetooth... Electromagnetic signals have become a ubiquitous information transmission medium in modern human production and life. While bringing us convenience in life, they also conceal the risk of sensitive information leakage. The alarm bell for a leak to a leak needs to sound for a long time. Electromagnetic leakage is an intangible physical phenomenon. When we use electronic devices with electromagnetic conductivity such as computers, printers, scanners, etc., these devices are like small radio stations that can transmit the electromagnetic energy processed inside the device to the surrounding space in the form of electromagnetic waves without people noticing, causing electromagnetic leakage. This is an objective phenomenon that cannot be avoided during the use of electronic devices, and usually does not pose a direct threat to information security. However, the electromagnetic leakage generated by electronic devices when processing sensitive and classified information can be intercepted and analyzed by malicious individuals through peripheral receiving devices, resulting in the theft of relevant information and causing "electromagnetic leakage". In 2013, the "Snowden incident" exposed multiple secret intelligence monitoring projects in the United States, including a espionage operation codenamed "DROPMIRE", which captured electromagnetic waves generated during the password fax work of the European Union's representative office in Washington, D.C., and stole its transmission content. Compared with traditional methods of information theft, using electromagnetic leakage for theft has extremely strong concealment. It does not require direct contact, but rather intercepts intangible electromagnetic waves and restores them during normal device operation to achieve information theft, leaving almost no trace and difficult to detect and stop in a timely manner. If not prevented, it may not only threaten government, military, scientific research institutions and other classified units, but also affect key fields such as finance, energy, and communication. Once core data is stolen, it can lead to business competition failure and economic losses, and in severe cases, it may endanger national security and strategic interests. Although electromagnetic leakage cannot be avoided, according to its inherent technical principles and logic, it is possible to build an electromagnetic space security defense line, enhance technical defense capabilities, create an effective security prevention system, and prevent and resolve electromagnetic leakage risks. ——Multi dimensional blockade of technical defense system. Prioritize the use of low radiation equipment to reduce signal source strength. At the same time, electromagnetic shielding measures are implemented for classified areas to effectively block the path of radiation leakage; Deploy electromagnetic jammers to disrupt the analyzability of radiated signals. Implement full encryption processing for confidential information to ensure that even if the signal is intercepted, the original information cannot be restored; Using radiation resistant cables, filtering circuits, and other technical means to suppress the generation of parasitic signals. ——Dual track cooperation and prevention among institutional personnel. Strengthen the full lifecycle control of equipment, strictly distinguish between classified and non classified equipment, and resolutely prohibit the misuse of storage media; Regularly monitor the electromagnetic leakage level of equipment and establish a comprehensive risk ledger; Establish a sound electromagnetic safety management system and develop safety management processes covering key areas such as signal traceability, key updates, and equipment management; Strengthen the safety awareness education of staff, actively carry out special training activities on preventing electromagnetic leakage, educate and guide staff to accurately identify high-risk scenarios of electromagnetic leakage, and be familiar with measures to prevent electromagnetic leakage. ——The general public protects together. Preventing electromagnetic leakage is a silent competition to safeguard information security, which requires the joint efforts of the government, enterprises, and all citizens to prevent and respond. The general public, especially the staff of confidential units, should effectively enhance their awareness of electromagnetic leakage prevention, develop good information security habits, avoid using electronic devices to process confidential information in unsafe electromagnetic environments, and prevent unauthorized disassembly and modification of office equipment to prevent electromagnetic leakage caused by improper operation. If people find suspicious clues, they can report to the local national security authorities directly through the 12339 national security organ reporting acceptance telephone, the online reporting platform (www.12339. gov.cn), the WeChat official account of the Ministry of National Security, or the reporting acceptance channel. (New Society)