The generation system of ID card numbers in various countries usually contains elements such as regional codes, birthday information, and verification codes. The rules vary greatly from country to country. The following are examples and algorithm analysis of ID card systems in several typical countries： --- ### 1. **Chinese resident ID card (18 digits)** -**Structure**: 'AAAAAA YYYYMMDD NNS C` -**AAAAAA**: 6-digit address code (province/city/district) -**YYYYMMDD**: 8-digit date of birth -**NNS**: 3-digit sequence code (odd male/even female)+Police station code -**C**: 1 digit check code (0-9 or X) -**Verification algorithm** (ISO 7064 MOD 11-2)： 1. The first 17 digits are multiplied by the weight coefficient `[7,9,10,5,8,4,2,1,6,3,7,9,10,5,8,4,2]`； 2. After summing, modulo 11 to obtain the remainder'z`； 3. Through the remainder look-up table: 'z:0 1 2 3 4 5 6 7 8 9 10 → C: 1 0 X 9 8 7 6 5 4 3 2`。 -**Example**: The check code of `11010519491231002X` is calculated as `X`. --- ### 2. **U.S. Social Security Number (SSN, 9 digits)** -**Structure**:'AAA-GG-SSSS` -**AAA**: Area number (once represented the place of birth, now randomly assigned) -**GG**: Group number (no special rules) -**SSSS**: sequence number -**Rules**： -Does not contain a check code, but some combinations of numbers are retained (such as invalid ones starting with 000)； -Since 2011, randomized distribution has been adopted, which no longer reflects geographical location. --- ### 3. **Japan My Number (12 digits)** -**Structure**:`12 digits` -The first 11 digits are randomly generated, and the last 1 digit is the check code； -**Verification algorithm**： 1. The first 11 digits are multiplied from right to left by the weight of`n=1'to`n=11` (if'n≤6', the weight is`n+1'; otherwise, it is`n-5`)； 2. After summing, modulo 11, the result is `11-(sum% 11)` (if the result is 10, take 0). --- ### 4. **French INSEE code (15 digits)** -**Structure**: Contains information such as gender, date of birth, and place of birth. -**Check code calculation**： 1. The first 13 digits are converted to numbers (letters need to be transcoded)； 2. Calculate`97-(num% 97)` for the first 13 digits to get the last two check codes. --- ### 5. **India Aadhaar (12 digits)** -**Structure**: 12 random digits, no explicit personal information. -**Verification**: Use the **Verhoeff algorithm** to detect single-character input errors through the permutation table. --- ### 6. **Korean resident registration number (13 digits)** -**Structure**:`YYMMDD-BBCCCCD` -**YYMMDD**: Date of birth (those born after 00 years are represented by the letter'a-T` for the year)； -**BB**: Area code and gender； -**CCCC**: Random code； -**D**: Check code (calculated by modulo 11 algorithm). --- ### 7. **German tax ID (11 digits)** -**Structure**: Contains date of birth, area code and verification code. -**Verification algorithm**: Verified by modulo 10 alternating weighting method. --- ###**Common characteristics** 1. **Check code**: Most systems use modulo operations (such as modulo 11, modulo 10) or specific algorithms (such as Verhoeff) to prevent counterfeiting； 2. **Embedded information**: Birthday, gender, and place of birth are common in Asian countries, and Europe and the United States are more inclined to de-personalize.； 3. **Randomization trend**: In recent years, new systems (such as SSN in the United States and Aadhaar in India) tend to reduce the risk of information leakage. --- ###**Precautions** -Some algorithms (such as German tax numbers) are not fully disclosed, and official tools are required to generate rules； -The processing of ID card data is subject to local privacy regulations (such as the EU's GDPR). If you need a more detailed example of a country's algorithm steps or code implementation, you can further explain it!