ParsedCloud Transfer needs a way to uniquely identify each user so that files sent or stored can be kept private and secure. We use your email address uniquely identify you for that purpose. During registration, the ParsedCloud Transfer application on your PC creates a private security key that never leaves your computer. That is the only key that will work to open your ParsedCloud files. We also create a pseudo lock (its really a public key) that others use to secure the files being sent to you. The ParsedCloud application finds this lock by using your email address.
People who want to send you a file will identify you using your registered email address. And they will borrow the lock assigned to that email address to secure the files being sent to you. Any files delivered to you can only be opened with that unique private key that you hold.