I’m using Wuala’s cloud storage for some years now, and I tried to challenge the status quo to see if there are better alternatives available in the meantime. The main requirement for me is a zero-knowledge provider, a provider that does not know my password and cannot decrypt my data (without brute force). I found these candidates:
Wuala, Tresorit, SpiderOak, MEGA, SeaFile
(Note that SeaFile is a self-hosted open-source solution.) The next requirement is location: Servers should not be located in the USA, and there should be an Android client that supports upload ...
Wuala, Tresorit, SpiderOakDouble-Plonk!, MEGA, SeaFile
... and there should be an official Linux client ...
Wuala, TresoritPlonk!, MEGA, SeaFile
... and the service shouldn’t require exotic TCP ports such that clients work behind a corporate firewall ...
Wuala, MEGA, SeaFilePlonk!
... and the service should support file revisions, download on demand only, and files should stay encrypted on client exit ...
Wuala, MEGATriple-Plonk!
Way to go, Wuala!