The security of pervasive computing devices relies on cryptographic engines which are usually considered the most trusted part of the system. An immanent threat to embedded cryptographic engines are physical attacks. Practical countermeasures against physical attacks are not completely fail-safe and overly expensive for most applications. Theoretical approaches, however, still tend to have imperfect leakage models and wrong or impractical assumptions about the abilities of cryptographic sub-primitives. Yet, the theoretical concepts of leakage resilience, which have been mostly disregarded by practitioners, carry a great potential to construct cryptographic primitives that resist physical attacks and allow for more resource-efficient implementations.
The project investigates solutions for basic cryptographic services that are (i) secure in the presence of physical attacks and (ii) are comparable in performance and costs to state-of-the-art implementations of cryptography. This is achieved by enhancing the concepts of leakage resilience to make them applicable in the constrained regimes of embedded pervasive systems. Theoretical concepts are advanced and brought into practice by actual implementation. Practical evaluation uncovers remaining weaknesses in the currently used leakage models. By combining the advantages of both approaches ? a thorough practical evaluation of the applied methods and the well-defined leakage-resilience of the theoretical approaches ? stronger, more reliable, and practical solutions are derived. Besides an increased security for the wide range of embedded products, the findings give valuable feedback to both theoretic cryptographers and practical security architects.
Only security solutions that are leakage resilient, withstand practical evaluation and match economic expectations guarantee a widespread use and hence more secure pervasive systems.
