create security for only one user in php witout database and encode php code

hi all


<b>Problem 1 :</b>

i create a web app with php for wordpress database that take some operatioan on database

now i want create security for it ...

my app dosnt have any database

what is a best method for create a security for web app pages ?

i need to use what ?


<b>problem 2 :</b>
I want to sell this web app
I want to encode my php code
I want when any one buy my web app , enter the domain name , and web app work only in entered domain name

My goal is that no one else can have it Except buyer .

Finally ... I want encode my php code with minimum of requirment in user side ... and my app work in special domain

please help me

thanks a lot