Mask mobile numbers in MySQL

Masking mobile numbers in MySQL can be done using string functions such as CONCAT and SUBSTRING. Below is an example of how to implement this:

CREATE FUNCTION MaskMobileNumber(mobileNumber VARCHAR(15)) RETURNS VARCHAR(15)

BEGIN

    DECLARE maskedNumber VARCHAR(15);

    

    IF LENGTH(mobileNumber) = 10 THEN

        SET maskedNumber = CONCAT('XXX-XXX-', RIGHT(mobileNumber, 4));

    ELSEIF LENGTH(mobileNumber) = 11 THEN

        SET maskedNumber = CONCAT('XX-XXX-', RIGHT(mobileNumber, 4));

    ELSEIF LENGTH(mobileNumber) = 12 THEN

        SET maskedNumber = CONCAT('X-XXX-', RIGHT(mobileNumber, 4));

    ELSEIF LENGTH(mobileNumber) = 13 THEN

        SET maskedNumber = CONCAT('XXX-XXXX-', RIGHT(mobileNumber, 2));

    ELSEIF LENGTH(mobileNumber) = 14 THEN

        SET maskedNumber = CONCAT('XX-XXXX-', RIGHT(mobileNumber, 2));

    ELSEIF LENGTH(mobileNumber) = 15 THEN

        SET maskedNumber = CONCAT('X-XXXX-', RIGHT(mobileNumber, 2));

    ELSE

        SET maskedNumber = 'Invalid Mobile Number';

    END IF;

    RETURN maskedNumber;

END;

Usage:

SELECT MaskMobileNumber('1234567890') AS MaskedNumber;

This will output XXX-XXX-7890.

Here are few FAQs:-

1. Why should mobile numbers be masked in a database?

   - Mobile numbers may contain sensitive information, and masking them helps protect user privacy, especially in scenarios where data is shared or accessed by multiple parties.

2. Can the original mobile number be retrieved from the masked version?

   - Ideally, the masking process should be irreversible to maintain data security. Therefore, the original mobile number should not be retrievable from the masked version.

3. How can I ensure that masked mobile numbers are still usable for certain operations?

   - By retaining some part of the original mobile number, such as the last few digits, you can maintain the usability of the data for operations like identification or verification, while still protecting sensitive information.

4. Are there any legal requirements for masking mobile numbers?

   - Depending on the jurisdiction and the nature of the data being handled, there may be legal requirements or industry standards mandating the protection of personally identifiable information (PII), which includes mobile numbers.

5. Can I customize the masking format to suit my specific requirements?

   - Yes, the provided masking function can be customized to accommodate different formatting preferences or variations in mobile number structures. You can modify the function logic accordingly to meet your needs.