Expansion f(R21,K1)=P(S(E(R21)K)) Expansion E 3212345 456789 8910111213 21314151617 161718192021 202122232425 242526272829 28293031321 1818 Expansion •f (Ri-1 , Ki ) = P(S(E(Ri-1 )  Ki )) Expansion E : 32 1 2 3 4 5 4 5 6 7 8 9 8 9 10 11 12 13 12 13 14 15 16 17 16 17 18 19 20 21 20 21 22 23 24 25 24 25 26 27 28 29 28 29 30 31 32 1