Using Java: 

Implement the RC4 stream cipher in C++ or JAVA. User should be able to enter any key that is 5 bytes to 32 bytes long. Be sure to discard the first 3072 bytes of the pseudo random numbers. The key is not allowed to be hardcoded.

Test the program using the following plain text:

In cryptography, RC4 (Rivest Cipher 4 also known as ARC4 or ARCFOUR meaning Alleged RC4) is a stream cipher. While remarkable for its simplicity and speed in software, multiple vulnerabilities have been discovered in RC4, rendering it insecure. It is especially vulnerable when the beginning of the output keystream is not discarded, or when nonrandom or related keys are used. Particularly problematic uses of RC4 have led to very insecure protocols such as WEP.