[matthewaveryusa]

This is completely insecure sorry. A cautionary tale of how this works in reality if this product is successful is to look at hushmail, one of the first ultra-popular webmail sites that provided end-to-end encryption from Canada (via a java applet) -- they updated their terms and services after many years of running and fighting US court orders with this statement:

"Hushmail is a web-based service, the software that performs the encryption either resides on or is delivered by our servers. That means that there is no guarantee that we will not be compelled, under a court order issued by the Supreme Court of British Columbia, Canada, to treat a user named in a court order differently, and compromise that user's privacy."

https://www.wired.com/2007/11/hushmail-to-war/

To hushmails credit, they were making a protocol that was insecure by default a bit more secure.

Shellvault is doing the opposite which is not commendable