function getCrypt(key)

math.randomseed(key)

function getIndex(stringIn,tableOut)
    for k,v in ipairs(tableOut) do
        if stringIn == v then
            return k
        end
    end
    return false
end

function defChar()
    local charset = {}
    charset.lower = ' abcdefghijklmnopqrstuvwxyz'
    charset.upper = string.upper(charset.lower)
    charset.number = '0123456789'
    local fullcharset = charset.lower .. charset.upper .. charset.number
    local chartbl = {}
    for echChar in string.gmatch(fullcharset,'%Z') do
        table.insert(chartbl,echChar)
    end
    return chartbl
end

function ver(table, str)
    for k,v in ipairs(table) do
        if str == v then
            return true
        end
    end
    return false
end

local charset = defChar()
local cryptset = {}

for i=1,#charset do
    while true do
        local bct = string.char(math.random(33,126))
        if not ver(cryptset,bct) then
            table.insert(cryptset,bct)
            break
        end
    end
end

return charset, cryptset
end

function encrypt(str, key)

local alfabeto, encrypt = getCrypt(key)
local encryptedStr = ''
local strtbl = {}

for ecchi in string.gmatch(str, '%Z') do
    table.insert(strtbl, ecchi)
end

for k,v in ipairs(strtbl) do
    local jcheck = getIndex(v,alfabeto)
    if jcheck then
        encryptedStr = encryptedStr .. encrypt[jcheck]
    end
end

return encryptedStr

end

function decrypt(str, key)

local alfabeto, encrypt = getCrypt(key)
local decryptedStr = ''
local strtbl = {}

for ecchi in string.gmatch(str, '%Z') do
    table.insert(strtbl, ecchi)
end

for k,v in ipairs(strtbl) do
    local jcheck = getIndex(v,encrypt)
    if jcheck then
        decryptedStr = decryptedStr .. alfabeto[jcheck]
    end
end

return decryptedStr

end