TinyStream: A Lightweight and Novel Stream Cipher Scheme for Wireless Sensor Networks

Implementation performance and key randomness are two key issues for stream cipher systems. In this paper, a lightweight stream cipher with good randomness of key stream is firstly proposed. It utilizes a novel proposed model named tree parity machine to generate streams. The most superiority of our scheme is that 128 bits could be generated based on one time of state rotation, and it passes the full ENT randomness test. Then, implementation of the proposed scheme for wireless sensor networks, Tiny Stream, is presented. Tiny Stream is based on TinySec protocols, and just costs 65024 bytes ROM and 1659184 bytes RAM with a subtle rather than that of TinySec. Due to the simple structure and small computation, Tiny Stream is considered to be good for secure communication applications in the resource constraint WSNs.