Round gating for low energy block ciphers

Pushed by the pervasive diffusion of devices operated by battery or by the energy harvested, energy has become one of the most important parameter to be optimized for embedded systems. Particularly relevant would be to optimize the energy consumption of security primitives. In this paper we explore design techniques for implementing block ciphers in a low energy fashion. We concentrate on round based implementation and we discuss how gating, applied at round level can affect and improve the energy consumption of the most common lightweight block cipher currently used in the internet of things. Additionally, we discuss how to needed gating wave can be generated. Experimental results show that our technique is able to reduce the energy consumption in most block ciphers by over 60% while incurring only a minimal overhead in hardware.