Terrible Hashing Algorithm

hashhash.lua

local function getTranslatedMessage(mode, message, key) --https://santoslove.github.io/caesarcipher.html
    if mode:sub(1, 1) == 'd' then
        key = -key
    end
    translated = ''
    for i = 1, #message do
        local symbol = message:sub(i,i)
        if symbol == symbol:match('%a') then
            num = string.byte(symbol)
            num = num + key

            if symbol == symbol:upper() then
                if num > string.byte('Z') then
                    num = num - 26
                elseif num < string.byte('A') then
                    num = num + 26
                end
            elseif symbol == symbol:lower() then
                if num > string.byte('z') then
                    num = num - 26
                elseif num < string.byte('a') then
                    num = num + 26
                end
            end
            translated = translated .. string.char(num)
        else
            translated = translated .. symbol
        end
    end
    return translated
end


local function getKey(l)
	while l > 26 do
		l = l - 26
	end
	return l
end
local function hash(p)
	local l = p:len()
	local p = p:gsub('[%p%c%s]', '')
	math.randomseed(l*l)
	if l > 16 then
		error("Invalid password length!")
	elseif l < 16 then
		while p:len() < 16 do
			local char = ""
			if math.random(1,5) == 1 then
				char = 64 + math.random(1,26)
			else
				char = 96 + math.random(1,26)
			end
			p = p .. string.char(char)
		end
	end
	local mode = " "
	if l % 2 == 0 then
		mode = "d"
	end
	return getTranslatedMessage(mode,p,getKey(l))
end
term.write("Enter Password: ")
print(hash(read()))