Features of the RC4 algorithm include:

• simplicityThe proposed algorithm has a simple structure and is easily programmable, especially in software.
• fast speedOn most systems, RC4 provides high encryption speeds.
• variable key lengthRC4 allows keys of different lengths, typically ranging from 40 to 2048 bits.

Over time, however, the security of RC4 has come under increasing scrutiny. Researchers have identified a range of potential vulnerabilities and attack methods that make RC4 no longer recommended for use in environments with high security requirements.

Weaknesses of RC4：

• deviation of key stream: Predictable bias in early output bytes, which could be exploited for attacks.
• key reuseAs with all stream encryption algorithms, key reuse is dangerous because it allows an attacker to exploit key stream duplication to break the encryption.

RC4-drop

However, with the advent of more secure encryption algorithms such as AES, and continued questioning of the security of RC4, the use of RC4 has declined significantly. Modern encryption standards and protocols generally recommend the use of more secure encryption algorithms.