Open Access

This thesis is dedicated to models and algorithms for the use in physical cryptanalysis which is a new evolving discipline in implementation security of information systems. Physical observables such as the power consumption or electromagnetic emanation of a cryptographic module are so-called `side channels'. They contain exploitable information about internal states of an implementation at runtime. Physical effects can also be used for the injection of faults. Fault injection is successful if it recovers internal states by examining the effects of an erroneous state propagating through the computation. The best currently known approach in physical cryptanalysis is a thorough experimental verification at a profiling stage, which is included in methods achieving maximum power. The final multivariate algorithms of this thesis can be seen as the most efficient ones in side channel cryptanalysis.

TinyECC 2.0 is an open source library for Elliptic Curve Cryptography (ECC) in wireless sensor networks. This paper analyzes the side channel susceptibility of TinyECC 2.0 on a LOTUS sensor node platform. In our work we measured the electromagnetic (EM) emanation during computation of the scalar multiplication using 56 different configurations of TinyECC 2.0. All of them were found to be vulnerable, but to a different degree. The different degrees of leakage include adversary success using (i) Simple EM Analysis (SEMA) with a single measurement, (ii) SEMA using averaging, and (iii) Multiple-Exponent Single-Data (MESD) with a single measurement of the secret scalar. It is extremely critical that in 30 TinyECC 2.0 configurations a single EM measurement of an ECC private key operation is sufficient to simply read out the secret scalar. MESD requires additional adversary capabilities and it affects all TinyECC 2.0 configurations, again with only a single measurement of the ECC private key operation. These findings give evidence that in security applications a configuration of TinyECC 2.0 should be chosen that withstands SEMA with a single measurement and, beyond that, an addition of appropriate randomizing countermeasures is necessary.

Dieser Beitrag betrachtet den Stand der Entwicklung bei der Vernetzung von Fahrzeugen aus Sicht der IT-Sicherheit. Etablierte Kommunikationssysteme und Verkehrstelematikanwendungen im Automobil werden ebenso vorgestellt und diskutiert wie auch zukünftige Kommunikationstechnologien Car-2-Car und Car-2-X. IT-Sicherheit im Automobil ist ein schwieriges Feld, da es hier um eine Integration von neuen innovativen Anwendungen in eine hochkomplexe bestehende Fahrzeugarchitektur geht, die zu keinen neuen Gefährdungen für die Fahrzeuginsassen führen darf. Zudem bleibt die Funktionsweise dieser Anwendungen mit ihren Auswirkungen auf das informationelle Selbstbestimmungsrecht oft intransparent. Die abschließende Diskussion gibt Handlungsempfehlungen aus Sicht der Verbraucher.