Editing RC4 (section)

===Implementation===
Many stream ciphers are based on [[linear-feedback shift register]]s (LFSRs), which, while efficient in hardware, are less so in software. The design of RC4 avoids the use of LFSRs and is ideal for software implementation, as it requires only byte manipulations. It uses 256 bytes of memory for the state array, S[0] through S[255], k bytes of memory for the key, key[0] through key[k−1], and integer variables, i, j, and K. Performing a modular reduction of some value modulo 256 can be done with a [[bitwise AND]] with 255 (which is equivalent to taking the low-order byte of the value in question).