January 29, 2002
Practical Aspects of Modern Cryptography
15
Rijndael Key Schedule
…
k
11
k
10
k
9
k
8
k
7
k
6
k
5
k
4
k
3
k
2
k
1
k
0
…
Round key 2
Round key 1
Round key 0
n
The key schedule is defined on 4-byte words by
n
n
k
i
= k
i
-4
Ä
k
i
-1
when
i
is not a multiple of 4
n
k
i
= k
i
-4
Ä
f(k
i
-1
)
when
i
is a multiple of 4