In recent years, with the rapid iteration of technology and upgrading of consumption, consumers' demand for the performance and experience of smartphones has been continuously increasing, and the replacement cycle of mobile phones in China has significantly shortened. According to data from the China Association for Recycling Materials, China produces an average of about 600 million to 700 million discarded mobile phones annually. These second-hand mobile phones contain enormous circular economy value - phones with good condition can be re entered into the market circulation after professional testing, data cleaning, and refurbishment processing; Damaged mobile phones can be disassembled to obtain core components such as chips, screens, and batteries for spare parts repair; Completely scrapped mobile phones are refined into precious metals through environmentally friendly processes, which can efficiently recover rare metals such as gold, silver, platinum, palladium, etc., achieving the maximum utilization of resources. As the world's largest producer and consumer of mobile phones, China's second-hand mobile phone recycling rate is not high. The long-term idle or unregulated disposal of a large number of second-hand mobile phones not only causes resource waste, but also poses environmental pollution risks. Promoting the recycling of second-hand mobile phones has become an urgent task for the development of circular economy. One important reason why a large number of second-hand mobile phones would rather be idle than sold is that users are concerned that the data stored on their phones may not be wiped clean, leading to personal information leakage. At present, there are three main reasons why mobile phone storage data cannot be erased cleanly: firstly, the data erasure operation prompts are not clear. Before processing second-hand mobile phones, users usually use the phone's built-in functions such as "restore factory settings", "quick formatting", and "one click deletion" to erase data. However, some mobile phones require multiple options to be stacked to erase all data, which is difficult for ordinary users to effectively recognize, resulting in omissions in user deletion. The second issue is that the erasing method is not thorough. Currently, there is a lack of mandatory standards and specifications for erasing mobile phone storage data. Even if users follow the prompts, most mobile phones only adopt a strategy of erasing data storage indexes and directories once. Although relevant files are deleted, the original data can actually be restored through technical means such as scanning the storage file system and reassembling data fragments. Thirdly, the recycling channels are not standardized. Currently, second-hand mobile phones are recycled through multiple channels such as mobile phone manufacturers, distributors, repairers, and second-hand mobile phone trading platforms, lacking secure, reliable, and efficient data erasure and verification services. In March 2024, the State Council issued the "Action Plan for Promoting Large scale Equipment Renewal and Consumer Goods Trade in", proposing to "promote the standardization of second-hand electronic product transactions, prevent leakage and malicious recovery of user information". To implement relevant requirements, all parties in the industry actively explore and accelerate the innovation, research and application of specialized technologies such as secure erasure algorithms, data coverage rewriting, and erasure effect verification, in order to solve the bottlenecks and difficulties in the recycling of second-hand mobile phones. In terms of data erasure technology specifications, the National Network Security Standardization Technical Committee, China Communications Standardization Association and other standard associations have organized the development of national and industry standards such as requirements for data erasure technology for second-hand mobile phone recycling and service management standards for second-hand mobile phone trading platforms, guiding upstream and downstream enterprises in the recycling of second-hand mobile phones to establish multiple data erasure guarantee systems. The standard proposes specific requirements from multiple levels. At the mobile phone level, file system full disk encryption technology should be used to securely encrypt user data. When users perform a "factory reset", the encryption key destruction mechanism should be triggered to ensure that the original data cannot be recovered, achieving complete erasure of user data from a technical level. At the level of second-hand mobile phone trading platforms, it is necessary to implement data cleaning solutions that comply with international standards, using secure and effective data cleaning tools to repeatedly overwrite and fill the user's mobile phone storage area, ensuring complete overwriting of hardware storage units. Recently, under the guidance of the Information and Communications Management Bureau of the Ministry of Industry and Information Technology, the China Academy of Information and Communications Technology has organized the construction of a mobile terminal data erasure verification platform, vigorously promoting standardized verification tools and technical specifications, and providing authoritative data erasure certification services for the industry. The data erasure verification tool adopts end-to-end multi-level data recovery and other technical means to perform a full disk scan of storage spaces such as disk sectors, system partitions, and databases. It supports comprehensive evaluation of data clearing records, clearing function processes, and user data residues of some common brands of mobile phones on the market, comprehensively verifying the authenticity and effectiveness of data clearing capabilities. At the same time, the platform can generate information clearing authentication identifiers for users to independently query, reducing their concerns about personal information leakage and making them more willing to participate in the recycling of second-hand mobile phones. In addition, the China Academy of Information and Communications Technology, in collaboration with the Taier Certification Center, has developed a series of certification technical specifications for second-hand mobile phone trading platforms and user data erasure. These standards comprehensively evaluate recycling products and enterprises from three aspects and carry out relevant certification work. One is the second-hand mobile phone trading platform, which certifies the full process management capabilities such as handling environmental safety, facility and equipment management, and security audit protection. The second is the ability to clear mobile phone data, with a focus on verifying key indicators such as the clear function prompt, clear range notification, and data clear status of "restoring factory settings". The third is data erasure tools, which authenticate their core capabilities such as erasure methods, erasure integrity, and security protection measures. Products and enterprises that have passed the above certification will be issued certification certificates that can be found on the official website of the State Administration for Market Regulation, effectively guiding consumers to participate in the action of circular economy resource utilization and jointly promoting green, low-carbon and sustainable development. The prospect of recycling second-hand mobile phones in our country is broad, and it is also an important part of promoting industrial upgrading? Policy guidance, technology drive, consumer synergy, and ecological win-win "? As the core path, multiple parties will work together to build a more efficient, safer, and sustainable recycling system, injecting green energy into high-quality development. (Author: Wang Yanhong, Deputy Director of the Information Security Department at the Taier Terminal Laboratory of China Academy of Information and Communications Technology) (Xinhua News Agency)