CRYPTOLOGY - Hacking: The Art of Exploitation - page 442

Seed = IV concatenated with the key
K []=41591 XXXX 41591 XXXX
S []=0123456789101112131415
KSA step one:
i =0
j = j + S [ i ]+ K [ i ]
j =0+0+4=4
Swap S [ i ] and S [ j ]
K []=41591 XXXX 41591 XXXX
S [] = 4 123 0 56789101112131415
KSA step two:
i =1
j = j + S [ i ]+ K [ i ]
j =4+1+15=4
Swap S [ i ] and S [ j ]
K []=41591 XXXX 41591 XXXX
S [] = 4 0 23 1 5 6 7 8 9 10 11 12 13 14 15
KSA step three:
i =2
j = j + S [ i ]+ K [ i ]
j =4+2+9=15
Swap S [ i ] and S [ j ]
K []=41591 XXXX 41591 XXXX
S []=40 15 31567891011121314 2
KSA step four:
i =3
j = j + S [ i ]+ K [ i ]
j =15+3+1=3
Swap S [ i ] and S [ j ]
K []=41591 XXXX 41591 XXXX
S []=40 15 31567891011121314 2
output − j − S [4] = key[1]
6 − 3 − 1=2