Marketing Cloud AmpScript BaseDecode64

Question

I have a question with base64decode function.

The following variables are not getting decoded when passed in the cloud pages. In email I am using following ampscript.

Email

%%[ 

VAR @Member_Number, @Email_Address,@LPURL 
SET @Member_Number = Base64Encode(MemberNumber) 
SET @Email_Address =Base64Encode(EmailAddress) 
SET @LPURL = Concat('http://example.com/page.aspx?EmailAddress=',@Email_Address,'&Member_Number=',@Member_Number)

]%%
%%=RedirectTo(@LPURL)=%%

When someone clicks, on above following gets captured in landing page. I am using insertdata function to capture the subscribers details. However when I click on the records in DE, they are still coming as encrypted.

Landing Page

%%[

VAR @Member_Number, @Email_Address, @ClickDate
/* Get Data From DE */
SET @Member_Number = RequestParameter("Member_Number")
Set @Member_Number1 = Base64Decode(@Member_Number)
SET @Email_Address = RequestParameter("EmailAddress")
SET @Email_Address1 = Base64Decode(@Email_Address)
SET @ClickDate = Format(SystemDateToLocalDate(NOW()),"yyyy-MM-dd HH:mm:ss")

IF NOT EMPTY(@Member_Number) THEN

   InsertData("LandingPageDE","MemberNumber", @Member_Number1, "EmailAddress", @Email_Address1, "ClickDate", @ClickDate)

ENDIF
]%%

Answer 1

Base64 Encoded strings typically contain + and = characters, so you will need to URL encode your Base64 strings if you are going to use them as URL parameters.

Try this:

%%[ 
VAR @Member_Number, @Email_Address,@LPURL 
SET @Member_Number = Base64Encode(MemberNumber) 
SET @Email_Address = Base64Encode(EmailAddress) 
SET @LPURL = Concat('http://example.com/page.aspx?EmailAddress=',URLEncode(@Email_Address),'&Member_Number=',URLEncode(@Member_Number))
]%%
%%=RedirectTo(@LPURL)=%%

AMPscript should decode any URL encoded strings (which is probably why there is no URLDecode AMPscript function).

However, I am curious to find out why you are Base64 encoding the strings in the first place (and not just using URLEncoding). If it's for 'security' then Base64Encode is really only "security through obscurity" and not a good idea. You would be better off using EncryptSymmetric and DecryptSymmetric if you want to obfuscate these parameters.