I have been pondering this for a while.  I wanted to build something that would act as either as a local backup target with offsite backup capabilities or as a full blown network storage device with the same capabilities.  If this works I will be able to offer my clients secured local storage capabilities with secured offsite storage that is not only encrypted in transfer but encrypted at rest.  Here is how it would work:

1.  Local device at clients location acting as either a file server/NAS/Backup target has compressed/de-duplicated/encrypted local storage available at all times.
2. This machine will have it’s own encrypted keys which means the data will not be readable by anyone else at any time without access to the control panel or webgui while the machine is on.
3. This appliance will then send it’s previously secured data over a separately encrypted connection to an offsite backup server(run by me) to store the clients data offsite for DR purposes. this data will arrive on my infrastructure already encrypted without me ever knowing the key.
4. The data will be further protected against intrusion via strict ACL’s so that nobody but the clients machine can read that data.
5. My server will then send its data to a third party using yet another encryption key that will securely transport ALL client backups as further redundancy for both myself and my clients.

This will allow me to get the residual income for the backup services instead of all the other vendors AND add a HUGE amount of security as well.  Once I figure this out(and I have an idea how) I will have a complete end-to-end appliance solution for a reasonable cost with much higher security than anything before it.  This could take weeks, months or longer but it is something I am determined to figure out..:)  I’ll move this from the Research Project area to Testing once i get the theoreticals figured out.

*update jan 28, 2016*  I have number 1,2,4 and 5 figured out.  #3 is a partial sticking point.  The encrypted connection to my remote infrastructure isn’t the issue.  it is sending them pre-encrypted over the encrypted connection.  However the remote server would also have a full encrypted filesystem so there is no place where the data is in plain text externally.  The sticking point(and this is where the MAJOR security upgrade against ALL other cloud vendors is) is #3.  The fact that I have the rest figured out means i can move from theoretical to testing.  The issue with #3 is my software that I want to use will not send the data snapshots over to my infrastructure pre-encrypted.  This means I would need to be able to setup individual encrypted jails on the receiving end to preserve the level of security I want to achieve(which would be at a level higher than any other backup vendor I know of right now). As of right now implementing the system would be HIPAA compliant and would be a substantial upgrade over other storage systems at the local level.  Once i figure out #3 I am confident I will have the most secure end-to-end data security solution available for small businesses available.

*Update Dec 28th, 2017*  My premise has changed.  Number 5 is no longer needed as number 3 has been solved in a different way.  The latest version of the software I intend to use(FreeNAS) can now send encrypted backups to serveral cloud vendors directly.  This overcomes one of the biggest limitations of the platform that I was trying to work around.  I can now start testing in earnest with my own FreeNAS machine.

*Update Feb 17th, 2018* As goes with any research project sometimes premises change..and then change back.  I have figured out my original premise from the Jan update from last year is still the one to go with.  Right now I only have 1,2, and 4 figured out.  3 and 5 are not solved to my satisfaction yet.  I DO have the replications figured out thought.  The only things I have to get nailed down is the encryption specifics.  Once I can get that nailed down I will be able to move quickly from testing to initial launching.