How RC4 Works

Now that you understand the very basics of encryption, let’s take a closer look at how it is implemented in RC4. RC4 is a synchronous stream cipher that uses XOR to combine output from a key stream generator with the plaintext of the message. When used properly, its state value is relatively unpredictable; thus, it is a strong, fast, and valuable method for encrypting data. This algorithm was created by RSA Data Security, but was leaked on a newsgroup in 1994. Although the algorithm is a trade secret of RSA, RC4 has found its way into several technologies. These technologies include Secure Sockets Layer (SSL) and WEP.

The leaked RC4 algorithm is commonly referred to as ARC4 (assumed RC4). RSA never acknowledged that the leaked ...

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