Data Masking is a crucial process in SQL Server that helps protect sensitive data and Personal Identifiable Information (PII) from unauthorized access. In this article, we will explore the concept of Dynamic Data Masking and how it can be implemented in SQL Server.

What is Dynamic Data Masking?

Dynamic Data Masking is a feature in SQL Server that allows you to hide sensitive data by applying different masking rules. When unauthorized users access the masked data, they will only see the masked values and not the actual data. This helps protect sensitive information from being exposed.

Types of Dynamic Data Masking

There are four types of Dynamic Data Masking in SQL Server:

• Default Masking: This type of masking applies a default mask depending on the data type. For example, string data types are masked to ‘XXXX’, numeric data types are masked as 0, and date time data types are masked to a specific date.
• Partial Masking: Partial masking allows you to customize the masking to meet your specific requirements.
• Random Masking: Random masking is applied to numeric values within a given range. When the value is retrieved, it will be replaced with a random value within the specified range.
• Email Masking: Email masking is used to mask email addresses. The first letter of the email address is replaced with a suffix followed by ‘.com’.

Implementing Dynamic Data Masking in SQL Server

To implement Dynamic Data Masking in SQL Server, you can create a table with relevant masking functions. Here’s an example:

CREATE TABLE EmployeeData (
  MemberID INT IDENTITY PRIMARY KEY,
  FirstName varchar(100) MASKED WITH (Function = 'default()'),
  LastName varchar(100) MASKED WITH (Function = 'partial(1, "XXX", 1)'),
  Email varchar(100) MASKED WITH (Function = 'email()'),
  Age int MASKED WITH (Function = 'default()'),
  JoinDate date MASKED WITH (Function = 'default()'),
  LeaveDays int MASKED WITH (Function = 'random(1, 5)')
);

You can then insert records into the table and query the data. The masked data will be displayed according to the masking rules applied.

Implementing Dynamic Data Masking in Azure SQL

Dynamic Data Masking can also be implemented in Azure SQL Databases. In Azure SQL, there is a user interface available for configuring data masking rules. You can choose from recommended fields for masking or add custom masking rules.

Unlike SQL Server, Azure SQL provides additional data masking options such as credit card values. You can also modify existing data masking rules in Azure SQL.

Conclusion

Dynamic Data Masking is a powerful feature in SQL Server that helps protect sensitive data from unauthorized access. By applying different masking rules, you can ensure that only authorized users can view the actual data. Whether you are using SQL Server or Azure SQL, Dynamic Data Masking provides an effective way to secure your data.