Abstract. Side Channel Attacks (SCA) have received a huge interest in the last 5 years. These new methods consider non-cryptographic sources of information (like timing or power consumption) in addition to traditional techniques. Consequently block ciphers must now resist a variety of SCAs, among which figures the class of "collision attacks". This recent technique combines side channel information with tools originally developed for block cipher or hash function cryptanalysis, like differential cryptanalysis for instance. In this paper, we propose techniques to enhance collision attacks. First we describe a general framework for collision attacks against Feistel ciphers that extends and improves on previous results specifically obtained against DES. Then, we describe an improved method to attack DES using "almost collisions". Indeed we observed that taking into account internal states which are abnormally similar results in more efficient attacks. Some experimental results obtained against a DES implementation are finally presented.
Side-Channel Analysis for Reverse Engineering (SCARE) is a new field of application for Side-Channel Attacks (SCA), that was recently introduced, following initial results on the GSM A3/A8 algorithm. The principle of SCARE is to use side-channel information (for instance, power consumption) as a tool to reverse-engineer some secret parts of a cryptographic implementation. SCARE has the advantage of being discrete and non-intrusive, so it appears to be a promising new direction of research.In this paper, we apply the concepts of SCARE in the case of the block cipher DES. We measure the power consumption of a software DES executed on a target smart card and propose new methods to exploit this information. We manage to retrieve many details about the underlying device, including some constants used by the algorithm (e.g. permutation tables for the round function and for the key scheduling), but also interesting implementation choices (e.g. registers where subkeys are loaded). Of course some information was already known in our case, but situations can be envisaged where the designer would like to keep it secret. An application of these methods is to reverse-engineer a proprietary algorithm, provided some information about its basic structure is know. Hence it illustrates the power of SCARE and demonstrates yet again the accuracy of Kerckhoff's principle. In addition, a better understanding of a cryptographic implementation can be a first step to mount more sophisticated Side Channel Attacks.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.