Lock your cloud backups away with an encryption key
It’s generally easier to keep safe the files we have under our control, on our internal and external drives, than those that waft far away from us on cloud-storage backup systems. Different backup services handle how they send data for storage and how they encrypt it once it arrives.
A quick overview of how cloud-storage systems work, regardless of the company. Client software running on your Mac finds new files in specified folders or files that have updated modification times since the last scan. Files are analysed into pieces against which the software calculates a sort of shorthand or signature. This signature is compared against what’s stored in the cloud. If it matches, nothing happens – this is how these services conserve bandwidth.
But if it doesn’t match or there’s no stored record for that chunk, the software opens a connection to transmit the actual data, typically compressed and always in a secure client-to-server session. The data is then stored with redundancy on the service’s drives, sometimes across geographically dispersed data centres.
