Quick, Simple Base64 Module

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A cool funny module I created for anyone to use. I don’t need credit or attribution. The code isn’t obfuscated and there are a few comments I put in to give an idea of how it works.
The point of the module isn’t security, although you could just change the base64 characters to mess around with people. After benchmarking, it is clear it is really fast. Although improvements can be made to some things, it would just make it too unclear to understand.

Link to module:
https://create.roblox.com/store/asset/17896299586/Base64

--!native
--A cool funny module made by me (Comet_Quasher) for Base64 encryption and decryption.
--I don't need credit or attribution, anyways have fun with Base64.
--VGhhbmtzIHNvIG11Y2ggZm9yIHVzaW5nIG15IHNjcmlwdHMhISE

local Base64 = {}
local base64Characters = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
local indexTable = {}

--//Prepare index table
for i=1,64 do
	indexTable[i-1]=string.sub(base64Characters,i,i)
end

--[[EXAMPLE
Binary Conversion of 8 to 8-bit-binary
8%2 = 0, 8/2 = 4
4%2 = 0, 4/2 = 4,
2%2 = 0, 2/2 = 1,
1%2 = 1,

1000 (4-bit segment)
Still needs to be a 8-bit segment

8-4 = 4
Which basically means 4 zeros are required to be added to the back of the segment.
00001000 (8-bit segment)
]]
local function ConvertToBinaryBitString(number:number,length:number)
	--//Convert the number to a binary bit string using modulo
	local binaryString = ""
	while number > 0 do
		binaryString=(number%2)..binaryString
		number=math.floor(number/2)
	end
	--//Ensures the binary bit string is of appropriate length by adding necessary zeros at the back
	binaryString=string.rep("0",length-#binaryString)..binaryString
	return binaryString
end

local function ConvertBinaryBitToNumber(bit:string)
	local number=0
	local length=#bit
	for i=1,length do
		if bit:sub(i, i) == "1" then
			number += 2^(length-i)
		end
	end
	return number
end


function Base64.Encode(data:string):string?
	--//Convert characters to 8-bit segments
	local bitStream=""
	for i = 1, #data do
		local charByte = data:byte(i)
		bitStream..=ConvertToBinaryBitString(charByte,8)
	end
	
	
	--//Add padding to ensure it is a multiple of 6 so we can split it into 6-bit segments
	local Padding = (6 - #bitStream % 6) % 6
	bitStream..=string.rep("0",Padding)
	
	
	--//Convert 6-bit segments to Base64
	local encodedData = ""
	for i = 1, #bitStream, 6 do
		local segment = bitStream:sub(i,i+5)
		local index = tonumber(segment,2)
		encodedData..=indexTable[index]
	end
	
	
	--//Add padding for missing bits to ensure encodedString is a multiple of 4
	Padding = (4 - #encodedData % 4) % 4
	encodedData..=string.rep("=",Padding)
	
	--//Clear variables
	bitStream,Padding=nil,nil
	return encodedData
end
function Base64.Decode(encodedData:string):string?
	--//Calculate padding bits to be added to ensure a multiple of 8
	local paddingBits=0
	for i = #encodedData, (#encodedData-1), -1 do
		if encodedData:sub(i,i) == "=" then
			paddingBits+=1
		else
			break
		end
	end
	
	--//Since we have no use for padding anymore we will simply remove them for now
	encodedData=string.sub(encodedData,1,#encodedData-paddingBits)
	
	--//Convert Base64 back to 6-bit segments
	local bitStream = ""
	for i=1,#encodedData do
		local character = string.sub(encodedData,i,i)
		local index = table.find(indexTable,character)
		local segment = ConvertToBinaryBitString(index,6)
		bitStream..=segment
	end
	
	--//Add padding bits calculated previously to ensure a multiple of 8
	bitStream..=string.rep("0",paddingBits)
	
	--//Convert 8-bit segments to characters
	local decodedData = ""
	for i = 1, #bitStream, 8 do
		local segment = bitStream:sub(i,i+7)
		local charByte = ConvertBinaryBitToNumber(segment)
		decodedData..=string.char(charByte)
	end
	return decodedData
end
return Base64

I would appreciate all feedback.

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