Secure File Exchange Platform

I'm working on a new startup with a partner and we're hoping to work with a qualified developer to build the system initially and then continue to work with you on an ongoing basis to release features and improvements. The basic premise is a secure (protected by SSL) system where users can upload documents easily, quickly but most importantly securely. Clients of the site can either request documents from someone by sending a request via the site, or they can send documents to someone. The website simply sends a notification message saying that a file is requested or uploaded. And the final feature for the beta is a self destruct/expiry feature where the sender or uploader can set if a file is to destruct after being access or should expire after a given period. Most businesses/organizations are now getting away from email as it's generally not secure and so often has strict file limitations in terms of type and/or size. The system will run on a cPanel CentOS server, which we own and can be customized as needed. I've posted a complete mechanical walk through down below. ## Deliverables Beta Mechanics: Cursor Beta Mechanics: (should put up a splash page saying it's coming and to signup for an invite) Signup: Simple: name and email (or drop name and just ask for email?) Auto-send welcome email with link to a quick walk through and account setup where they specify a password (any other clever ideas? Like maybe making the walkthrough their first file they receive?) Sending a file: Secure login to website Upload file (initially I say we set a 500MB file restriction) Set receiver information Check to set expiry and if so the date Check to set file self destruct (i.e. deletes itself after being downloaded) Send notification email to receiver Send notification email to sender when file is accessed/self-destructed/expired (should it also send a reminder 72 hours before expiry?) Ask to receive a file: Secure login to website Enter email address(es) of those you want to receive file from, set whether to prompt them to create an account System sends file request to email address(es) entered with a secure link for them to upload the file and where they can also set expiry and self destruct (or should it be simple and just a straight send the file) also prompts them to create an account if desired Send notice to requestor that file has been uploaded and it's then available through their account