Using Tweaks to Design Fault Resistant Ciphers

Side channel analysis and active fault analysis are now major threats to even mathematically robust cryptographic algorithms that are otherwise resistant to classical cryptanalysis. This paper focuses on designing encryption schemes that use secret tweaks to achieve innate security against fault analysis. The paper examines linear and non-linear secret tweak based versions of a recently proposed block cipher DRECON. The paper demonstrates that while both versions are secure against classical DFA, the non-linear tweak based version provides greater fault coverage against stronger fault models. Experimental results obtained on a SASEBO GII platform have been presented to establish the fact that combined security by construction against both DPA and DFA makes DRECON a strong candidate for the design of secure cryptographic primitives.