With apologies to William Shakespeare, I'd like to ask the question in the title. Think about it - you have a Hobson's choice. Do you:

a) transmit your data to your cloud provider in the clear
b) store your transmitted data inside the cloud in the clear
c) process your stored data in the clear
d) none of the above

OK, let's say you do everything in the clear. This is, of course, the most straightforward way to transmit and store your data in a cloud. Nothing out of the ordinary - in fact, this is by far the most common technique in datacenters today. Hardly anything in a traditional datacenter is stored encrypted, especially databases (structured data). Transmitted to/from the outside world, yes - but stored (i.e. data at rest), no. If you practice this technique, you run the risk of the cloud provider intercepting or viewing your data - even without malicious intent. As the kids would say, stuff happens.

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Read the rest of Robert Peglar's blog post, here at Cloud Lab.