Pseudocode for Key Expansion () Algorithm

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procedure Key Expansion (key)

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i ← 0 3

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while i ≤ Nk −1 do 4

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w[i] ← key[4 ∗ i..4 ∗ i + 3]

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i ← i + 1 6

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end while

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while i ≤ 4 ∗Nr + 3 do

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temp ← w [i − 1]

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if i mod Nk = 0 then

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temp ← SubWord(RotWord(temp))♁Rcon[i/Nk]

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else if Nk > 6 and i mod Nk = 4 then

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temp ← SubWord(temp)

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end if

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w[i] ← w[i−Nk]♁temp

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: i ← i + 1

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end while

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return w

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end procedure