We use SSL. As you might have noticed, we don't have any software that needs to be installed to use our service. We use the operating systems inbuilt 'Drive Mapping' feature, and all the communication is done over SSL.

Also, we are different from BackBlaze in the sense, ZapDrive appears as a different drive on your computer, so you don't need to save the same data on your hard drive. The downside is, you have to be connected to the Internet to access your files in ZapDrive.