Mask PII data in PostgreSQL

Masking data in PostgreSQL involves various techniques such as anonymization, tokenization, and encryption. Let's explore a real-life example of masking sensitive data, such as email addresses, in a database containing user information:-

Real-Life Example:

Consider a scenario where a company maintains a PostgreSQL database with a table named "users" containing sensitive user information, including email addresses. To comply with privacy regulations and protect user privacy, the company decides to mask email addresses by replacing the domain part with a generic domain.

Code Example:

Here's how you can mask email addresses in the "users" table using PostgreSQL SQL commands:

-- Create a view to mask email addresses

CREATE OR REPLACE VIEW masked_users AS

SELECT

    user_id,

    CONCAT('user', user_id, '@example.com') AS masked_email, -- Masked email with generic domain

    first_name,

    last_name,

    -- Include other columns as needed

FROM

    users;

-- Drop the original "users" table

DROP TABLE IF EXISTS users;

-- Rename the view to replace the original "users" table

ALTER VIEW masked_users RENAME TO users;

In this example, we create a view named "masked_users" that masks email addresses by replacing the domain part with "example.com". We also include other columns from the original "users" table as needed.

After creating the view, we drop the original "users" table and rename the view to replace it. This ensures that applications querying the "users" table continue to work seamlessly with the masked data.

Explanation:

- CREATE VIEW: We create a view named "masked_users" that generates masked email addresses using the CONCAT function to concatenate the user ID with the generic domain.

- DROP TABLE: We drop the original "users" table to remove the actual email addresses from the database.

- ALTER VIEW RENAME: We rename the view to replace the original "users" table, ensuring that existing applications can access the masked data seamlessly.

Masking mobile numbers in PostgreSQL can be achieved by replacing part of the digits with a consistent placeholder value, such as 'X'. Here's a code example demonstrating how to mask mobile numbers in a PostgreSQL database:

-- Create a view to mask mobile numbers

CREATE OR REPLACE VIEW masked_users AS

SELECT

    user_id,

    CONCAT('XXX-XXX-', RIGHT(mobile_number, 4)) AS masked_mobile, -- Masked mobile number

    first_name,

    last_name,

    -- Include other columns as needed

FROM

    users;

-- Drop the original "users" table

DROP TABLE IF EXISTS users;

-- Rename the view to replace the original "users" table

ALTER VIEW masked_users RENAME TO users;

In this example:-

- We create a view named "masked_users" that generates masked mobile numbers using the CONCAT function to concatenate the first part of the mobile number with 'XXX-XXX-' and the last four digits of the mobile number using the RIGHT function.

- We include other columns from the original "users" table as needed.

- After creating the view, we drop the original "users" table to remove the actual mobile numbers from the database.

- Finally, we rename the view to replace the original "users" table, ensuring that existing applications can access the masked data seamlessly.

This approach allows organizations to preserve the format of mobile numbers while masking the sensitive digits, thereby protecting user privacy while maintaining data integrity and usability. Adjust the masking technique and code according to your organization's specific requirements and data privacy regulations.

By masking sensitive data like email addresses, organizations can protect user privacy while still retaining the integrity and usability of the data for legitimate business purposes. Remember to adapt the masking techniques and code to suit the specific requirements and regulations governing your organization's data privacy and security.