AFTP

    function enc(str, key) -- Function
    local tProp = {} -- Make table
    for i = 1, str:len() do -- loop for str length
      local val = tonumber((str:byte(i) * tonumber(key) + (12.6 * key)) / 2.8)--Byte str times keyadd 12.6 times key and divide 2.8
      table.insert(tProp, val) -- rest is to return the data
    end
    return tostring(table.concat(tProp,"|"))
    end

    function dec(str, key)
    local data = {}
    for word in string.gmatch(str, "[^|]+") do
      local rdata = ((tonumber(word)*2.8)-(12.6*key))/key
      table.insert(data, math.floor(rdata+0.5))
    end
    return string.char(unpack(data))
    end


    --config

    side = "top" --modem
    rand = false --more secure not yet implemented
    btlp = false --not yet implement
    stpmsg = "end" --msg that indicates end of file
    shtdown = false -- if true will shutdown at end of file transfer
    gfb = true -- return current file size and other usefull data
    pmsg = "ping" --default ping msg
    dc = false --basic encryption method (eta will be wrong)
    vsn = 1.4 -- version
    cp = true -- keep pinging if failed connection

    --code
    rednet.open(side)
    term.clear()
    term.setCursorPos(1,1)
    print("Arpanet FTP "..vsn.."  |")
    print("(C) Aperture Labs 1970 |")
    print("---------------------#")
    print('Type help for command list')

    while true do
    ct = false
    write("action> ")
    p = read()

    if p == "help" then
    print[[help -cmd list
    exit -leave program
    id -computer id
    files -send file
    filer -receive file]]
    ct = true
    end

    if p == "id" then
    print(os.getComputerID())
    ct = true
    end

    if p == "filer" then
    write("ID> ")
    cid = read()
    stop = false
    cid = cid + 0
    write("save as: ")
    nami = read()
    h = fs.open(nami,"w")
    write("ping msg> ")
    rednet.send(cid,read())

    while stop == false do
    icid, pack = rednet.receive(2)
    if cp == false then
    if icid == nil then
    print("no connection established!")
    sleep(1.5)
    os.reboot()
    end
    else
    if icid == nil then
    print("no connection established.")
    sleep(1.5)
    end
    end
    if icid == cid then
    print("Received "..pack.." Saving to file")

    if pack ~= stpmsg then
    h.write(pack)
    if gfb == true then
    print(fs.getSize(nami))
    end
    else
    print("file complete!")
    if dc == true then
    write("key> ")
    keys = read()
    h.close()
    h = fs.open(nami,'r')
    nonen = h.readAll()
    h.close()
    h = fs.open(nami,'w')
    h.write(dec(nonen,keys))
    end
    if dc == false then
    h.close()
    end
    stop = true
    if shtdown == true then
    os.shutdown()
    else
    os.reboot()
    end
    end

    elseif icid ~= nil then
    print("Blocked Conection from ID: "..icid)
    end
    sleep(0)
    end

    ct = true
    end

    if p == "files" then
    write("file> ")
    nami = read()
    if dc == true then
    write("key> ")
    keys = read()
    end
    h = fs.open(nami,"r")
    if dc == false then
    wpack = h.readAll()
    else
    wpack = enc(h.readAll(), keys)
    end
    wpackt = {}

    print("Dividing into Packets may take a while!")
    for char in string.gmatch(wpack, ".") do
    table.insert(wpackt, char)
    sleep(0)
    end

    if gfb == true then
    print("hosting on "..os.getComputerID())
    eta = #wpackt * .01
    print("Estimated transfer time in seconds")
    print(eta)
    end

    while true do

    cid, auth = rednet.receive()
    stop = false
    c = 1
    wpn = #wpackt + 1
    if auth == "sup" then
    print("Seeding ID:"..cid)
    while c < wpn do
    rednet.send(cid, wpackt[c])
    c = c + 1
    sleep(0.01)
    end
    rednet.send(cid, stpmsg)
    print("Seed Complete!")

    elseif auth == pmsg then
    rednet.send(cid,nami)
    end
    sleep(0)
    end

    ct = true
    end

    if p == "exit" then
    print("Thankyou for using Arpanet FTP.")
    sleep(1.5)
    os.reboot()
    ct = true
    end

    if ct == false then
    print("ERR Unknown command.")
    end
    sleep(0)
    end