A survey of lightweight stream ciphers for embedded systems

Pervasive computing constitutes a growing trend, aiming to embed smart devices into everyday objects. The limited resources of these devices and the ever-present need for lower production costs, lead to the research and development of lightweight cryptographic mechanisms. Block ciphers, the main symmetric key cryptosystems, perform well in this field. Nevertheless, stream ciphers are also relevant in ubiquitous computing applications, as they can be used to secure the communication in applications where the plaintext length is either unknown or continuous, like network streams. This paper provides the latest survey of stream ciphers for embedded systems. Lightweight implementations of stream ciphers in embedded hardware and software are examined as well as relevant authenticated encryption schemes. Their speed and simplicity enable compact and low-power implementations, allow them to excel in applications pertaining to resource-constrained devices. The outcomes of the International Organization for Standardization/International Electrotechnical Commission 29192-3 standard and the cryptographic competitions eSTREAM and Competition for Authenticated Encryption: Security, Applicability, and Robustness are summarized along with the latest results in the field. However, cryptanalysis has proven many of these schemes are actually insecure. From the 31 designs that are examined, only six of them have been found to be secure by independent cryptanalysis. A constrained benchmark analysis is performed on low-cost embedded hardware and software platforms. The most appropriate and secure solutions are then mapped in different types of applications. Copyright (c) 2015 John Wiley & Sons, Ltd