Cryptanalytic weaknesses in modern stream ciphers and recommendations for improving their security levels

Abstract

Inthis paperwediscuiss security problems insom'1e modern stream ciphers. Asweobserve somie tinmes that adesigner claims that thealgorithm designed is mnore secure butt whenitcomestoopenliteratuire we finda numberQfproblems. We discuss SNOW, Scream andRabbit. Someejforts havebeenmadeto overcome theproblems those werepointed outin these cryptosystems bvdifferent cryptanalysts. The stream ciphers arefaster andefficient thanblock ciphers butconmparatively less secure. Ouremphasis inthis paperistomak-e somecompromise on efficiency buttogetnmor-e security. IndexTerms- Streamciphers, Blockciphers, SNOW,Scream, Rabbit, chaotic.