Ravi et al. present security-related challenges (“gaps”), unique to embedded system design (namely, security processing, power, tamper resistance, and assurance gaps), with associated descriptions of recent security advances, and opportunities for more research. After a brief introduction, discussing the importance and uniqueness of the embedded security challenges, an enumeration of security requirements, concepts, and design challenges are given.

The heart of this paper is the section on security processing requirements and architecture, starting with a popular secure sockets layer (SSL) protocol, and processing workload example. The gap associated with state-of-the-art processing is presented with respect to secure processing architecture and battery management examples. The next “tamper resistance and assurance gap” presents an overview of both logical and physical attacks on an embedded system, covering topics such as fault induction, and timing and power analysis. Finally, two case studies are presented: the OMAP 1610 processor, addressing the security processing gap for wireless handsets, and the ARM TrustZone, for thwarting software attacks.

This paper provides a good overview of some of the security issues for commercial embedded systems. The figures--covering processing requirements for SSL, energy consumption data for ciphers, and evolution of security protocols--were particularly useful in visualizing secure embedded processing trends. There are secure embedded challenges for defense systems--namely, MILS, covert channels, data separation, and so on--that would make a good complement to this paper.