A secured modular exponentiation for RSA and CRT-RSA with dual blinding to resist power analysis attacks

Abstract

Blinding has been one of the most effective approaches to resist power analysis attacks on asymmetric cryptosystems like RSA. Blinding is similar to masking in symmetric cryptosystems, but masking can be implemented in various ways like Boolean, affine, polynomial masking, etc. However, for asymmetric cryptosystems with modular exponentiation as a fundamental operation, arithmetic masking or simply blinding has been extremely popular. In this paper, we have presented a secured approach for modular exponentiation in RSA and CRT-RSA cryptosystems with dual blinding. Through dual blinding, we have masked both secret exponent and message twice before executing the fundamental operations. We have also injected two ineffectual instructions between the fundamental operations and blinded the intermediate results to felicitate hiding and resist simple power analysis. The implementation results shows that with a nominal penalty, RSA and CRT-RSA with dual blinding can effectively resist some popular simple power analysis and differential power analysis attacks to a significant extent.