Recently, it was reported on the Internet that there may be a risk of personal information leakage in second-hand mobile phone transactions, which has attracted widespread attention from the society. What are the risks of second-hand mobile phone trading? Can the deleted personal information in old phones be restored? How should our old mobile phones be handled correctly?
personal information leakage caused concerns in the second-hand mobile phone
After simple operations, a mobile phone that has deleted data and has used the "factory reset" function that comes with the mobile phone, and restores its original data. And there are also merchants who specialize in this kind of "business".
Recently, news circulating online that second-hand mobile phones can recover their original data through technical means, which has caused new anxiety about the public's information leakage due to the recycling of second-hand mobile phones.
So, after restoring the phone factory settings and deleting relevant content and software, is it reliable to sell your old phone?
"The principles and rules of information storage for traditional computers and today's smartphones are basically the same. Simple factory reset and deletion of files do not mean that the information has been completely deleted." Pei Zhiyong, a network security expert and director of the Qi'anxin Industry Security Research Center, said that the system actually deletes the indicated path of the file on the mobile phone, which means that ordinary people cannot find the file. However, the actual content information is still stored inside the mobile phone.
"So, it is possible to restore the content stored in the mobile phone before it is stored, and the technical threshold is not high." Pei Zhiyong admitted that at present, in some irregular second-hand mobile phone recycling stores, some people will restore the stored information in the mobile phone in this way, such as mobile phone address books, text messages and other content involving personal information, and then sell it for a second time to make huge profits.
Experts said that infringement of personal information is often the source of a series of illegal crimes such as telecom fraud , extortion, and malicious account registration. Data leakage will threaten users' personal property. Criminals collect people's personal information by restoring mobile phone data, screening and analyzing user characteristics, and engage in precise criminal activities such as telecommunications fraud, illegal debt collection and even kidnapping and extortion.
5 key vulnerabilities that have been hotly discussed in a long time ago
After the mobile phone is restored to factory settings, the data will still be restored by those who are interested, which is to some extent arising from the system vulnerabilities.
Take Android phones as an example. Computer researchers at Cambridge University once found that more than 500 million Android phones did not completely erase mobile phone data after restoring the factory settings. The "factory reset" function is a built-in feature of Android phone system. This is considered the most important function when selling and recycling mobile phones, and is used to erase all confidential information on the mobile phone. However, computer researchers found that even if the user turns on the full disk encryption function, the data may still be restored.
Researchers have drawn 5 mobile phones from different manufacturers from the second-hand market. According to their estimates, more than 500 million smartphones cannot effectively erase passwords and other sensitive data. In addition, about 630 million devices cannot erase external SD cards that store multimedia files such as pictures and videos.
5 key vulnerabilities:
1. 2.3.x's Android system cannot effectively delete data on disk.
2. Smartphone manufacturers do not provide updates to these vulnerable devices.
3. In the new Android versions, such as 4.1, 4.2 and 4.3, the manufacturer does not provide driver support for deletion operations.
4. All versions of Android systems cannot effectively delete data on built-in and external SD cards.
5. The vulnerability of full disk encryption extends these problems to the Android 4.4 KitKat system.
How to deal with old mobile phones has become a new trouble for "mobile phone family"
"Mobile phone replacement is becoming more and more frequent. I already have 7 or 8 old mobile phones at home. I don't know what to do after a few years, so I can only keep it." Xiao Wang, a citizen of Beijing, said that in addition to mobile phones, she also has several old laptops and desktop computers at home, which occupies a lot of space.
Data released by the Ministry of Industry and Information Technology shows that from January to February 2021, my country's mobile phone production reached 210 million units, a year-on-year increase of 49.2%, of which the production of smartphones reached 140 million units, a year-on-year increase of 48.8%.
"my country is a major smartphone user country, and the number of mobile phones produced and eliminated each year is huge." Telecom expert Fu Liang predicts that the scale of second-hand mobile phones will continue to increase.
With the rapid development of smartphones and the Internet, similar situations to Xiao Wang will become more and more common. Some consumers even have dozens of old mobile phones at home. Most people don’t know how to recycle and properly handle them. They can only put old mobile phones and old smart products at home to "eat dust".
"It's a pity not to sell, but I'll worry if I sell it." "It not only takes up space at home, but also cannot make use of the residual value of the mobile phone." "A half-old mobile phone can also be sold at a good price, but I'm also worried that personal information will be leaked." The messages left by netizens on the Internet represent the voice of many consumers.
As the number of old mobile phones continues to grow, consumers on the streets and shopping malls can see slogans such as "high-price recycling of mobile phones" and recycling stores from time to time. However, most consumers are not familiar with the mobile phone recycling and second-hand mobile phone sales industries. When recycling old mobile phones that have been used in close use, the public generally has concerns whether it will lead to potential risks such as leakage of important personal information and privacy.
The correct way to open old phones is
"Generally, when changing your phone, people generally pay attention to reducing the use and storage of key information on old phones, and the value of information on old phones begins to decay with time." Fu Liang said that some APP applications, payment-related identities and other information, even if they are restored by others, will have a relatively low chance of directly causing harm to mobile payments.
According to Fu Liang, the version upgrade and iteration speed of smart application software such as financial institutions' APPs and mobile payments is relatively fast. It is difficult to apply the user-related information recovered in second-hand mobile phones to the new version of the payment function. But if the data of privacy photos, especially important ID cards and other important documents are recovered, the hidden danger will be greater.
Recycling and reuse of outdated electronic products is the general trend. So the question is, how can we sell and recycle our old mobile phones while ensuring information security?
Pei Zhiyong suggested that first, try to sell old mobile phones to large platforms and large stores as much as possible, and try to avoid personal channels or small stores. Secondly, after replacing the old phone, don’t rush to sell it. In addition to restoring the factory settings and deleting old files before sale, you can choose to download the “File Smash” software to repeatedly overwrite and rewrite the eliminated phones and computers.
"The user can connect the phone to the computer, first delete all the contents of the phone, then write a new large file into the phone, repeat it several times, and try to fill its space." Pei Zhiyong said that this can basically ensure that the personal information and traces in the old phone are completely removed.
Experts recommend that you try not to save sensitive and secret information on your mobile phone. Important information should be deleted as soon as possible after saving and use. After multiple data coverage, the chance of data recovery will be greatly reduced.
Fu Liang believes that from the perspectives of world environmental protection and resource reuse, the development of the second-hand electronic product recycling industry represented by smartphones, computers, etc. is imperative. Relevant departments should study measures and regulations in advance to provide assistance to relevant recycling industries, so that recycling channels are more transparent and recycling methods are more scientific and accurate, so as to promote the healthy and orderly development of the industry.
"Clarify the standards for identifying recyclers' professional qualifications and introduce more detailed regulations and measures, so that our consumers can say 'no' to unidentified recyclers." Pei Zhiyong said that when legislation and regulations are formulated, second-hand mobile phone personal information leakage should be included in the overall scope of information protection, and unified planning and deployment measures should be contributed to improving the security protection of personal information.
Old mobile phones "refined" real gold
Chinese scientists invented the "photocatalytic dissolution of precious metals " technology
precious metals such as gold, silver, and platinum are widely used in electronic devices such as mobile phones because of their good physical properties, high chemical stability and strong corrosion resistance. How to better recycle these precious metals from waste equipment has always been a concern for scientists.
Recently, the "photocatalytic precious metal dissolution" technology invented by the Key Laboratory of Resource Chemistry and Education of Shanghai Normal University Li Hexing and Bian Zhenfeng's team has achieved efficient and green recycling of precious metals in scrapped electronic equipment, and is expected to promote changes in the field of precious metal smelting.
Information source: Xinhua News Agency, CCTV Finance, Computer News
