Cryptosystems based on continued fractions
Ali A. Kanso · Security and Communication Networks · 2010
Abstract In this paper, we propose three secret‐key cryptosystems based on the theory of continued fractions for possible use in cryptographic applications. We present and analyze a sequence of rational numbers, whose randomness properties are demonstrated using well‐know statistical packages. Accordingly, we propose a cryptosystem that acts on a group of characters at a time. Then, a binary keystream generator, generating keystreams with good randomness properties, is suggested for possible use in stream cipher applications. Finally, we propose a cryptosystem related to the well‐known Baptista's cryptosystem that is based on a chaotic logistic map. However, our cryptosystem is based on the theory of continued fractions, and is shown to exhibit better properties and decrypts information much faster than Baptista's cryptosystem. Copyright © 2010 John Wiley & Sons, Ltd.