Hola!
"The electronic data collected will be kept on a password protected computer".
I would say: "La data electrónica obtenida será guardada (or mantenida, but to me guardada sounds better) en una computadora protegida por contraseña"
In some countries we use the word "computadora" and in other countries people say "ordenador", but both are correct and people will understand you with any word you use.