Jan Schaeffner

Ievgen Kabin, Zoya Dyka, Dan Klann et al.

In this paper we discuss the difficulties of mounting successful attack against crypto implementations when essential information is missing. We start with a detailed description of our attack against our own design, to highlight which information is needed to increase the success of an attack, i.e. we use it as a blueprint to the following attack against commercially available crypto chips. We would like to stress that our attack against our own design is very similar to what happens during certification e.g. according to Common Criteria Standard as in those cases the manufacturer needs to provide detailed information. When attacking the commercial designs without signing NDAs, we needed to intensively search the Internet for information about the designs. We cannot to reveal the private keys used by the attacked commercial authentication chips 100% correctly. Moreover, the missing knowledge of the used keys does not allow us to evaluate the success of our attack. We were able to reveal information on the processing sequence during the authentication process even as detailed as identifying the clock cycles in which the individual key bits are processed. To summarize the effort of such an attack is significantly higher than the one of attacking a well-known implementation.

Dmytro Petryk, Zoya Dyka, Roland Sorge et al.

If devices are physically accessible optical fault injection attacks pose a great threat since the data processed as well as the operation flow can be manipulated. Successful physical attacks may lead not only to leakage of secret information such as cryptographic private keys, but can also cause economic damage especially if as a result of such a manipulation a critical infrastructure is successfully attacked. Laser based attacks exploit the sensitivity of CMOS technologies to electromagnetic radiation in the visible or the infrared spectrum. It can be expected that radiation-hard designs, specially crafted for space applications, are more robust not only against high-energy particles and short electromagnetic waves but also against optical fault injection attacks. In this work we investigated the sensitivity of radiation-hard JICG shift registers to optical fault injection attacks. In our experiments, we were able to trigger bit-set and bit-reset repeatedly changing the data stored in single JICG flip-flops despite their high-radiation fault tolerance.