Why is RC4 considered vulnerable despite being a stream cipher?

RC4 is considered vulnerable primarily because it was originally developed in 1984 and has since shown multiple weaknesses through cryptanalysis. Over the years, various attacks have been identified that exploit specific patterns in RC4's key-stream generation, which can lead to vulnerabilities in the encryption process. For instance, biases in the RC4 output can be exploited to recover plaintext from ciphertext, particularly in protocols that use the same key across multiple data packets.

The age of the algorithm is significant; as it has been around for several decades, researchers have had ample time to analyze it rigorously. The discoveries regarding its vulnerabilities have led to widespread consensus among security experts that it should no longer be used in secure communications.

Other options do not accurately reflect the core reasons for RC4's vulnerabilities. While the encryption length may be a concern in the context of key strength, it is not the primary reason for RC4's overall vulnerability compared to the specific weaknesses exploited through cryptographic attacks. The claim that RC4 cannot handle large sets of data is misleading, as it is a stream cipher designed to encrypt data of arbitrary lengths. Finally, the statement about not using pseudorandom values is not correct; RC4 generates a pseudo-random key stream from the initial key. Thus