Energy efficient C code for ARM devices

An interesting articles by Chris Shore which appeared in ARM Tech. Conference. Check it out here

My thought:
I'm more interested on how you improve securities in ARM devices and at the same time maintain or did not causes any harm to the devices efficiencies especially current era where attacks can be directed or coming from a small devices such as wireless sensor.

There will always a debate on security versus performance and you can only have one to choose. However, I would love to see something that be able to work in parallel for both security and performance :)