14   var Nb = 4;               // block size (in words): no of columns in state (fixed at 4 for AES)
15   var Nr = w.length/Nb - 1; // no of rounds: 10/12/14 for 128/192/256-bit keys
18   for (var i=0; i<4*Nb; i++) state[i%4][Math.floor(i/4)] = input[i];
20   state = AddRoundKey(state, w, 0, Nb);
23     state = SubBytes(state, Nb);
24     state = ShiftRows(state, Nb);
25     state = MixColumns(state, Nb);
26     state = AddRoundKey(state, w, round, Nb);
29   state = SubBytes(state, Nb);
30   state = ShiftRows(state, Nb);
31   state = AddRoundKey(state, w, Nr, Nb);
33   var output = new Array(4*Nb);  // convert state to 1-d array before returning [§3.4]
34   for (var i=0; i<4*Nb; i++) output[i] = state[i%4][Math.floor(i/4)];
39 function SubBytes(s, Nb) {    // apply SBox to state S [§5.1.1]  argument
41     for (var c=0; c<Nb; c++) s[r][c] = Sbox[s[r][c]];
47 function ShiftRows(s, Nb) {    // shift row r of state S left by r bytes [§5.1.2]  argument
50     for (var c=0; c<4; c++) t[c] = s[r][(c+r)%Nb];  // shift into temp copy
57 function MixColumns(s, Nb) {   // combine bytes of each col of state S [§5.1.3]  argument
75 function AddRoundKey(state, w, rnd, Nb) {  // xor Round Key into state S [§5.1.4]  argument
77     for (var c=0; c<Nb; c++) state[r][c] ^= w[rnd*4+c][r];
84   var Nb = 4;            // block size (in words): no of columns in state (fixed at 4 for AES)
88   var w = new Array(Nb*(Nr+1));
96   for (var i=Nk; i<(Nb*(Nr+1)); i++) {