1. A method for performing an RC4 stream cipher on an input data stream in an encryption accelerator, comprising: initializing an RC4 substitution box in a state memory, wherein the substitution box initialization includes: storing an incrementing pattern of values in incrementing memory locations in the state memory, and shuffling, upon direction of a state machine within the encryption accelerator, the values among the memory locations in the state memory based on a received key array having a plurality of portions, wherein the shuffling is performed with receipt of each portion of the key array by the encryption accelerator whereby an initial shuffled pattern of substitution values is generated via hardware and stored in a plurality of memory locations in the state memory; and generating, upon direction of the state machine, a random byte using the shuffled substitution box according to an RC4 cipher operation, wherein no central processing unit resources are invoked to perform the shuffling and generating components of the RC4 stream cipher.