Power and Energy Issues on Lightweight Cryptography

Portable devices such as smartphones, smart cards and other embedded devices require encryption technology to guarantee security. Users store private data in electronic devices on a daily basis. Cryptography exploits reliable authentication mechanisms in order to ensure data confidentiality. Typical encryption security is based on algorithms that are mathematically secure. However, these algorithms are also costly in terms of computational and energy resources. The implementation of security mechanisms on dedicated hardware has been shown as a first-order solution to meet prescribed security standards at low power consumption with limited resources. These are the guidelines of the so-called lightweight cryptography. Upcoming Internet of Thing (IoT) is extensively demanding solutions in this framework. Interestingly, physical realizations of encryption algorithms can leak side-channel information that can be used by an attacker to reveal secret keys or private data. Such physical realizations must therefore be holistically addressed. Algorithm, circuit and layout aspects are to be considered in order to achieve secure hardware against active and passive attacks. In order to address the challenges raised by the IoT, both academia and industry are these days devoting significant efforts to the implementation of secure lightweight cryptography. This paper is a survey of (i) lightweight cryptography algorithms; (ii) techniques to reduce power applied to cryptohardware implementations; (iii) vulnerability analysis of low-power techniques against sidechannel attacks; and (iv) possibilities opened to emerging technologies and devices in the "More than Moore" scenario.