Towards a General RC4-Like Keystream Generator
RC4 was designed in 1987 when 8-bit and 16-bit processors were commercially available. Today, most processors use 32-bit or 64-bit words but using original RC4 with 32/64 bits is infeasible due to the large memory constraints and the number of operations in the key scheduling algorithm. In this paper we propose a new 32/64-bit RC4-like keystream generator. The proposed generator produces 32 or 64 bits in each iteration and can be implemented in software with reasonable memory requirements. It has a huge internal state and offers higher resistance to state recovery attacks than the original 8-bit RC4. Further, on a 32-bit processor the generator is 3.1 times faster than original RC4. We also show that it can resist attacks that are successful on the original RC4. The generator is suitable for high speed software encryption.
KeywordsRC4 stream ciphers random shuffle keystream generator
Unable to display preview. Download preview PDF.
- 1.Biham, E., Granboulan, L., Nguyen, P.: Impossible and Differential Fault Analysis of RC4. Fast Software Encryption (2005)Google Scholar
- 2.Finney, H.: An RC4 cycle that can’t happen, Post in sci.crypt (September 1994)Google Scholar
- 8.Grosul, A., Wallach, D.: A related key cryptanalysis of RC4. Department of Computer Science, Rice University, Technical Report TR-00-358 (June 2000)Google Scholar
- 9.Jenkins, R.: Isaac and RC4. Published on the Internet, at http://burtleburtle.net/bob/rand/isaac.html
- 15.Mantin, I.: The Security of the Stream Cipher RC4. Master Thesis, The Weizmann Institute of Science (2001)Google Scholar
- 16.Maximov, A.: Two Linear Distinguishing Attacks on VMPC and RC4A and Weakness of the RC4 Family of Stream Ciphers. Fast Software Encryption (2005)Google Scholar
- 19.NIST statistical tests suite with documentation. Available on the internet at URL, http://stat.fsu.edu/~geo/diehard.html
- 22.Pudovkina, M.: Statistical Weaknesses in the Alleged RC4 keystream generator. Cryptology ePrint Archive 2002-171, IACR (2002)Google Scholar
- 23.Roos, A.: Class of weak keys in the RC4 stream cipher. Post in sci.crypt (September 1995)Google Scholar
- 24.Stubblefield, A., Ioannidis, J., Rubin, A.: Using the Fluhrer, Mantin and Shamir attack to break WEP. In: Proceedings of the 2002 Network and Distributed Systems Security Symposium, pp. 17–22 (2002)Google Scholar
- 25.Tsunoo, Y., Saito, T., Kubo, H., Shigeri, M., Suzaki, T., Kawabata, T.: The Most Efficient Distinguishing Attack on VMPC and RC4A. In: SKEW (2005)Google Scholar