On the Design of Trivium

eSTREAM called for new stream ciphers designed for niche areas such as exceptional performance in software and hardware where resources are restricted. This project provides an open platform to discuss these ciphers. Trivium is one of the promising new ciphers submitted to it. Until now, no attack has been successfully applied to it. This paper illustrates new design principles of stream ciphers based on the structure of Trivium and introduces the definition of k-order primitive polynomials. New designs of Trivium are also given according to the principles in this paper.