Base64 is used to encode binary data (e.g. metrics from Google Analytics) that needs to be stored and transferred over media that are designed to deal with textual data (e.g. Power BI). Contrary to belief, it is not a secure way to protect sensitive data.

Base 64 is an encoding algorithm, not an encryption algorithm, because it converts data into a reliable format, whereas encryption “hides” the data by protecting it with a password so that data can be viewed only by those who know the password.1

Here are the steps of the algorithm:

• The binary data gets converted to ASCII string format
• The ASCII is converted to binary format 8-bit
• The binary data gets divided into chunks of 6 bits each
• The 6 bit-chunks get passed to decimal number format
• The decimal format gets converted to a string according to the base64 Index Table to get the exact value of the decimal numbers

Creating a Custom Function

Copy and paste this text into the editor:

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WigoPyvGtSjbxCwkt8c1yNI0KNjDwc/HL9Ql3y4gM9yyJyvU08Q0JNYgKCcv1DwnLUoqNBQA=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type text) meta [Serialized.Text = true]) in type table [Column1 = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Column1", type text}}),
    #"Added Custom" = Table.AddColumn(#"Changed Type", "Custom", each Lines.FromBinary(Binary.FromText([Column1],BinaryEncoding.Base64), null, null, 1252){0})
in
    #"Added Custom"

Add a custom column:

Click again on our table and specify "ADD COLUMN >> CUSTOM COLUMN"

Copy this formula:

Lines.FromBinary(Binary.FromText(text,BinaryEncoding.Base64), null, null, 1252){0}

And replace text with the field you wish, for example:

{:width="50%" .align-center}