Static Transformation of Power Consumption for Software Attestation
Sean Kauffman, Carlos Moreno, Sebastian Fischmeister · 2016
Software attestation seeks to verify the authenticity of a system without the aid of trusted hardware, and has important applications in the field of security. Such attestation schemes are of particular interest in the embedded domain, where simplicity and limited resources constrain more complex security solutions. At the same time, these properties enable attestation approaches that rely on predictable side-effects. Most software attestation schemes aim to verify the integrity of memory using a combination of cryptographic schemes, internal side-effects like TLB misses, and known timing constraints. However, little attention has been paid to leveraging non-traditional side-effects, in particular, externally observable side-effects such as power consumption. In this paper we introduce a method for software attestation using power consumption as the side-effect. We show how to circumvent the undecidable nature of program execution for this purpose and present a static compiler transformation which implements the technique. Our approach is less intrusive than traditional software attestation because the system does not require interruption to compute a cryptographic checksum. It is particularly well suited to real-time systems where consistent timing is more important than speed.