Heres an excellent article in EE Times on writing energy efficient ARM code [https://www.eetimes.com/document.asp?doc_id=1279523](https://www.eetimes.com/document.asp?doc_id=1279523) .Our wolfSSL embedded SSL product is designed with many of these principles in mind, but of course the design goal of energy efficiency takes a back seat to overall security.  In some cases, the goals of energy efficiency and overall security mesh well.By the way, come see us at ARM TechCon.  If you need a pass, let us know at [info@yassl.com](mailto:info@yassl.com) and well send you one.