Design and setup of Power Analysis attacks

This paper presents how to design and setup a Simple Power Analysis (SPA) attack and a Differential Power Analysis (DPA) attack on a smartcard and on a 32 bit microcontroller. SPA and DPA are power analysis attacks developed by Paul Kocher, Joshua Jaffe, and Benjamin Jun in 1995. These are non-invasive techniques which allow us to observe electrical patterns of different types of cryptographic algorithms, only by measuring the power consumption of the cryptographic devices. This paper presents the results obtained by measuring the power consumption of a secure smartcard and a 32 bit microcontroller programmed with the tiny AES128 implementation and introduces the mathematical knowledge needed to extract the encryption keys based only on measurements. Using the DPA correlation coefficients algorithm, implemented in Matlab, we were able to extract the AES128 encryption key from captured power consumption traces. To obtain the measurements, an USB Scope was used. The interface to the smartcard was made using a Java platform to connect to the card reader.