Summary
International Symposium on Electromagnetic Compatibility
2014
Session Number:14P2-A
Session:
Number:14P2-A2
Analysis on Equivalent Current Source of AES-128 Circuit for HD Power Model Verification
Kengo Iokibe, Kazuhiro Maeshima, Tetsushi Watanabe, Hiroto Kagotani, Yasuyuki Nogami, Yoshitaka Toyota,
pp.-
Publication Date:2014/05/12
Online ISSN:2188-5079
Summary:
We analyzed equivalent current source of cryptographic circuits implemented on a field programmable gate array (FPGA). The equivalent current source represented internal switching current behaviors in the cryptographic circuits during an Advanced Encryption Standard (AES) operation. In this work, the internal current was analyzed for extracting leakage functions and correlation coefficients from scatter diagrams of the Hamming Distance (HD) of AES intermediate values and the current magnitudes. The obtained leakage functions were confirmed a well-known assumption on the HD power model that magnitude of switching current due to transition of register states is proportional to HD of the register. The internal current was also investigated in terms of correlation with the HD model. Correlation coefficients increased as transforming the external power trace in the internal current because two types of noise were reduced by the transform; constant noise and overlap effect of succ! essive rounds. The noise reduction inferred that the use of the internal current source would provide more precise verification of countermeasures.