There are quite a few options available from the stand-alone, like SpiderOak, to things that sit on top of Dropbox, such as Boxcryptor.
What I haven't seen is a comprehensive security review of these alternatives. There could be bugs, flaws, or they could outright not be doing what they claim to do.
What I haven't seen is a comprehensive security review of these alternatives. There could be bugs, flaws, or they could outright not be doing what they claim to do.