iStorage diskAshur Pro 1TB - Click to see the full review

Of all the portable storage devices I have reviewed during 2015 this is by far the most secure, to the point that this is what I now use to back up my own business data.  At the last company I worked for there were two instances where data was stolen by an ex-employee which led to the business losing thousands of pounds and creating hours of headaches so having a device that backs up all critical data with passwords and only known by the few who need to know is so important.