Cryptology ePrint Archive: Report 2008/396

Analysis of RC4 and Proposal of Additional Layers for Better Security Margin

Subhamoy Maitra and Goutam Paul

Abstract: In this paper, the RC4 Key Scheduling Algorithm (KSA) is theoretically studied to reveal non-uniformity in the expected number of times each value of the permutation is touched by the indices $i, j$. Based on our analysis and the results available in literature regarding the existing weaknesses of RC4, few additional layers over the RC4 KSA and RC4 Pseudo-Random Generation Algorithm (PRGA) are proposed. Analysis of the modified cipher (we call it RC4$^+$) shows that this new strategy avoids existing weaknesses of RC4.

Category / Keywords: secret-key cryptography / Bias, Cryptography, Keystream, KSA, PRGA, RC4, Secret Key, Stream Cipher

Publication Info: INDOCRYPT 2008

Date: received 19 Sep 2008, last revised 3 Nov 2011

Contact author: goutam k paul at gmail com

Available format(s): PDF | BibTeX Citation

Version: 20111103:105849 (All versions of this report)

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