Current flattening in software and hardware for security applications

Abstract

This work presents a new current flattening technique applicable in software and hardware. This technique is important in embedded cryptosystems since power analysis attacks (that make use of the current variation dependency on data and program) compromise the security of the system. The technique flattens the current internally by exploiting current consumption differences at the instruction level. Code transformations supporting current variation reductions due to program dependencies are presented. Also, real-time hardware architecture capable of reducing the current to data and program dependencies is proposed. Measured and simulated current waveforms of cryptographic software are presented in support of these techniques.