I need to remind you that if you buy a regular lottery ticket, your personal information will be protected by the "Personal Information Protection Law of the People's Republic of China" and other relevant provisions - no organization or individual may collect, use, or disclose the personal information of others for any reason or in any way, including the winner's phone number.
The common solution is to hide the middle 4 digits of the 11-digit domestic mobile phone number, and only keep the first 3 digits and the last 4 digits, such as "130XXXX5972". Through such a "semi-hidden number", the winner can roughly identify whether he has won the lottery or not, and at the same time, it is difficult for passers-by to accurately lock the winner, thus protecting the personal privacy of the winner to a certain extent.
But why are the last 4 digits publicly displayed instead of the middle 4 digits?
This is because these three parts of the mobile phone number correspond to different coding attributes, of which the middle 4 digits are bound to the attribution, the last 4 digits are the random code of the user himself, only the 4 digits of the random code are published without public attribution, if you want to determine who the number is, it is necessary to search and screen in the large database nationwide, and the difficulty is greatly increased, so the privacy and security of the number owner is ensured.
The last 4 digits are easier for the winner to identify (combined with the first three digits). Relatively speaking, the probability of the first 7 digits of different mobile phone numbers being the same is greater, taking the semi-public winner's number as an example, if the hidden number is changed from the last 4 digits to the middle 4 digits, many people will mistakenly think that they have won the prize.
Let's talk specifically about what information corresponds to the numerical encoding of these 11-digit mobile phone numbers.
(1) The first 3 digits correspond to the network identification number, which you can understand as the number segment assigned by which operator. For example, 139 and 158 are China Mobile, 130 and 155 are China Unicom, 133 and 189 are China Telecom, and some special numbers have to be counted to the fourth place, such as 1340~1348 is China Mobile, but 1349 is the number of China Telecom. Interested students can find out on their own.
(2) The 4th, 5th, 6th, and 7th digits correspond to the area code, which can be understood as the "attribution" that we were more concerned about a few years ago. For operators, the attribution is mainly conducive to the allocation and control of numbers.
(3) Different from the "category division" attribute of the first 7 digits, the last 4 digits of the mobile phone number are random numbers pointing to the user himself. This coding scheme is similar to ID card, bank card and other coding, which does not waste number resources, but also can be flexibly allocated and controlled, and a unique account is calibrated by the method of size grouping + feature code.
From the above information, we can draw a conclusion: the possibility that the 11-digit mobile phone numbers of different users are similar in the first 3 + 4 digits is much more likely to be the same than the combination of the first 3 + 4 in the back. If you hide the last 4 digits when you publish the number, there will be many identical "semi-public numbers", causing confusion.
When you only hide the middle 4 digits and leave the first 3 + last 4 digits to show people, it can not only protect the number from being easily identified by the public or accurately locked, but also allow the number owner to get a big self-identification. Obviously, this "semi-public number" scheme is more reliable.
However, for people with ulterior motives, even if you only leak the first 3 + the last 4 of the 7 numbers, they can also screen out the real person through technical means or with the help of some gray products. Protecting the privacy of citizens is a long way to go.