Dynamic Data Masking keeps playing…keep your hands off my data!

As promised, I have been playing with Dynamic Data Masking and here are some things I have learned.  I downloaded World Wide Importers so I would have a place to play and there were masked columns already included.

This query will show us what has already been masked:

SELECT mc.name, t.name as table_name, mc.is_masked, mc.masking_function
FROM sys.masked_columns AS mc
JOIN sys.tables AS t
 ON mc.[object_id] = t.[object_id]
WHERE is_masked = 1;

Here we can see the column and the table that is being masked and what masking function is being used.

masking 1

This is a great time to talk about the different masking functions and what they do.  The four types in 2016 are Default, Email, Random and Custom String.

Default – For numeric and binary it will show a “0” For a date it will show 01/01/1900 and for strings it will show xxxx’s (more or less depending on the size of the field).

Email – It will expose the first letter of the email address and the suffix at the end of the email (.com, .net, .edu etc.) For example Batgirl@DC.com  would now be bxxx@xxxx.com.

Random – Number randomly generated between a set range. Kind of like the game, “Pick a number between 1 and 10” but for SQL.

Custom String – Lets you get creative with how much you show or cover and what you use to cover (not stuck with just xxxx’s).

Now for fun, let’s create a table that will be masked.

CREATE TABLE SuperHero
(HeroId INT IDENTITY PRIMARY KEY
,HeroName VARCHAR(100)
,RealName VARCHAR(100) MASKED WITH (FUNCTION = 'partial(1,"XXXXXXX",0)') NULL
,HeroEmail VARCHAR(100) MASKED WITH (FUNCTION = 'email()') NULL
,PhoneNumber VARCHAR(10) MASKED WITH (FUNCTION = 'default()') NULL);

Let’s add some data that we will want to mask:

INSERT SuperHero (HeroName, RealName, HeroEmail, PhoneNumber) VALUES
('Batman', 'Bruce Wayne', 'batsy@heros.com', '5558675309' ),
('Superman', 'Clark Kent', 'manofsteel@heros.com','5558675308' ),
('Spiderman', 'Peter Parker', 'spidey@heros.com','5558675307' );

SELECT * FROM SuperHero;

and finally we add some low level permissions of people who will look at the masked version of the data:

CREATE USER CommonPeople WITHOUT LOGIN; 
GRANT SELECT ON SuperHero TO CommonPeople; 

Now the test to see if CommonPeople have access to see all of our Superhero secrets:

EXECUTE AS USER = 'CommonPeople';
SELECT * FROM SuperHero; 
REVERT;

Try it out and see for yourself how it looks. Now you have experienced Dynamic Data Masking 101 in SQL Server 2016!

The song for this post is Good Charlotte – Keep Your Hands Off My Girl

All the Masking in the World Can Maybe Cover Your Dirty Laundry….

I have spent the last week learning about new features in SQL Server 2016 and one that I want to play with is Dynamic Data Masking (DDM).

What is data masking? It is a way to change or hide sensitive data. If I want to hide an email address that is Batgirl@DC.com,  I could either change it to be Batwoman@Heros.com using a masking software or I could use DDM to cover it like this BXXXXX@XXXXXX.com. I can also determine how many letters I want to cover with the masking in DDM.

If you want to permanently mask it for security purposes and force it to never link back to your production data, SQL Server Dynamic Data Masking (DDM) is not for you.  The built-in feature only applies a mask over the top, it doesn’t actually change the data that is stored in the database.   Think of SQL Servers’ version of data masking like a Halloween mask that sits on your face as opposed to plastic surgery that will forever change the way you look.

SQL Servers’ DDM will mask data to users that you set up to see the mask.  This is helpful for reporting or for curious people who want to look at data they shouldn’t be viewing.  It will not hide the data from privileged users.  It will not protect your data from someone taking a backup and restoring it somewhere else (If you want that, try Alway Encrypted instead). As a side note, DDM and Alway Encrypted won’t work together on the same column.

Now let’s get ready to play with Dynamic Data Masking in SQL Server.  (Coming next month)

Today’s song is Dirty Laundry by Carrie Underwood.