How to hide my password?

pass = ("123")
osacces = ("123123")
tries = 3
triesfull = 0
print ("Password:")

for triesnum = 1,tries,1 do
password = read ()

if password == osacces then
print ("os activated")
break
end

if password == (pass) then
print ("Door is open!")
redstone.setOutput("back", true)
shell.exit()
sleep(5)
redstone.setOutput("back", false)
os.shutdown()
else
print ("Wrong Password!")
print ("Password:")
triesfull = triesfull + 1
end

end

if triesfull == tries then
os.shutdown()
end

password = read("*")
-- right now we set it so that as you type it looks like ******. you can change it to @@@@, AAAA, BBBB, whatever you want as long as it is a character. you put it in the ""