Atom: A Stream Cipher with Double Key Filter

It has been common knowledge that for a stream cipher to be secure against generic TMD tradeoff attacks, the size of its internal state in bits needs at least twice length secret key. In FSE 2015, Armknecht and Mikhalev however proposed Sprout with Grain-like architecture, whose was equal key yet resistant attacks. Although had other weaknesses, it germinated sequence designs like Lizard Plantlet short states. Both these have cryptanalytic results reported them. this paper, we propose Atom an 159 offers security 128 bits. uses two filters simultaneously thwart certain attacks recently keystream generators. addition, found our design is one smallest ciphers level, prove paper resists all so far literature. On face it, also builds on basic structure Grain family ciphers. However, try by including additional filter architecture can make immune advances recent cryptographic