T-SQL function for data scrambling

Question

GOAL: I have to obfuscate sensible data on a SQL Server database. Dynamic Data Masking is not an option. Data shuffle is not an option. The only option is Data Scramble.

SOLUTION: In the most hidden meander of the internet I found a very nice piece of code that can easily adapt to most of the data type:

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--A view to give you Random Values
CREATE VIEW dbo.random(value) AS SELECT RAND();

GO
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--Randomization Procedure
CREATE FUNCTION dbo.fnRandomizedText (
@OldValue AS VARCHAR(MAX)
)RETURNS VARCHAR(MAX)

BEGIN

  DECLARE @NewValue AS VARCHAR(MAX)
  DECLARE @nCount AS INT
  DECLARE @cCurrent AS CHAR(1)
  DECLARE @cScrambled AS CHAR(1)
  DECLARE @Random AS REAL
 
  SET @NewValue = ''
  SET @nCount = 0
   WHILE (@nCount <= LEN(@OldValue))
  BEGIN
    SELECT @Random = value FROM random
    SET @cCurrent = SUBSTRING(@OldValue, @nCount, 1)
     IF ASCII(@cCurrent) BETWEEN ASCII('a') AND ASCII('z')
       SET @cScrambled = CHAR(ROUND(((ASCII('z') - ASCII('a') - 1) * @Random + ASCII('a')), 0))
    ELSE IF ASCII(@cCurrent) BETWEEN ASCII('A') AND ASCII('Z')
       SET @cScrambled = CHAR(ROUND(((ASCII('Z') - ASCII('A') - 1) * @Random + ASCII('A')), 0))
    ELSE IF ASCII(@cCurrent) BETWEEN ASCII('0') AND ASCII('9')
       SET @cScrambled = CHAR(ROUND(((ASCII('9') - ASCII('0') - 1) * @Random + ASCII('0')), 0))
    ELSE
       SET @cScrambled = @cCurrent

    SET @NewValue = @NewValue + @cScrambled
    SET @nCount = @nCount + 1

  END
   RETURN LTRIM(RTRIM(@NewValue))
END
GO 
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Thanks to this function every name or surname can be scrambled this way:

SELECT
[FirstName],
UserName = dbo.fnRandomizedText([FirstName])
FROM [AdventureWorks2014].[Person].[Person]

FirstName	UserName
Ken	Tkm
Terri	Pggkg
Roberto	Thewgnu
Rob	Trs
Gail	Dgbp

And with the same function I can scramble e-mail addresses:

SELECT 
[EmailAddress]
,email = dbo.fnRandomizedText([EmailAddress])
FROM [AdventureWorks2014].[Person].[EmailAddress]

EmailAddress	email
[email protected]	[email protected]
[email protected]	[email protected]
[email protected]	[email protected]
[email protected]	[email protected]
[email protected]	[email protected]

This is an amazing piece of code and I would like to add the option to scramble dates.

Is there a way to scramble in the same way dates this way:

Dates	New_Dates
11/09/2003	12/01/1995
12/12/2021	13/02/1956
30/05/1998	23/03/1988
14/01/1984	01/02/1980

That might not be easy because the DataType for dates is much more complex. And I cannot tell how I can approach this problem. Any suggestion?