We also need end-to-end encryption of voice and text, on mobile networks. And there's absolutely no technical reason preventing it today. As for cloud: you encrypt all data before uploading it. Encrypted cloud providers do exist. Though unless you inspect their client's code, or do the encryption yourself, there's still some level of trust. Cloud computing is harder. Homomorphic encryption simply isn't practical yet. If you're doing cloud computing, you have to trust the provider.Now how does that square with the move to the cloud and handheld devices?
But will we see applications for encrypted cloud applications other than file backup systems? Today's tech companies don't seem to see too much of an incentive for encrypting their customer's data. There are many advantages that come with being able to sift through tons of information. In fact, much of the cool stuff that mobile and web apps offer today depend on centralized processing of the data. Still, I am sure that we will see a move back to the client in at least some areas in the future. The magic is in decentralised systems like Bitcoin that take advantage of their distributed nature. Especially for applications that deal with personal or confidential information this will be very interesting. I am looking forward to it!