ANALYSIS OF WAYS TO IMPROVE THE RC4 STREAM ENCRYPTION ALGORITHM

DOI: 10.31673/2409-7292.2025.011455

Abstract

The article considers the problems associated with increasing the stability of the RC4 cipher, which is used in network
protocols of modern distributed computer systems. Over the past decade, some weaknesses have been discovered in the RC4
encryption algorithm, the presence of which is explained by the simplicity of the algorithm embedded in it. The main such
weakness is the correlation between the secret key and the encryption gamma formed on its basis. The article provides an
analysis of the methods proposed by various authors to eliminate this drawback by complicating the key planning algorithms
and the formation of pseudo-random numbers. It is concluded that solutions based on a simple increase in the complexity of the
algorithm by implementing additional cryptographic transformations are not effective, since this deprives the RC4 cipher of its
speed. Because of this, it is proposed to give preference to solutions based on 32/64-bit microprocessor systems, which allow
significantly increasing the space of internal states of the encryption algorithm without a noticeable decrease in the speed of the
encryption process.
Keywords: RC4 stream cipher, random permutation, key stream, cipher gamma, cryptanalysis, weak internal state, weak
keys.

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