Guessing in re: A cloud of clouds
I'm just hazarding a guess that you neither looked at the ICStore diagram, understand the implication of KVS BLOB storage across resilient, heterogenous storage, and the other facets glossed over but addressed in the linked IBM piece and two papers.
This actually looks very usable from my point of view, especially the base encryption and total isolation of ICStore clients from one another, as well as have a total separation of concerns surrounding the... wait for it... similarly isolated cloud databases. Of course, being a toolkit, the devil will really be in the details of the implementation by IBM and any other engineering firms you might involve. [And no, I wouldn't let a 'developer' anywhere near this.] The only niggling worry I have is around the metadata leakage just might weaken the overall encryption. Any information/energy leakage does this and perhaps having information about the KVS keys might present a hazard. I have to defer to the thorough experts on that issue.