1024-bit expanded key(EK) generation

(1)256-bit “Padded Key”PK is generated with constant pattern KS

(2)PK is split into eight 32-bit strings PK1,….,RK8.

(3)OAP1, OBP1, EAP1 and EBP1 are defined.

(4)OAPi, OBPi, EAPi and EBPi are defined. i=2,3,4

(5)RVi,j+1 is given by

(6)RKi=RVi,5|RVi,4

PK=trunc256(K|KS)

PK=PK1|….|PK8

OAP1=PK1|PK8 , OBP1=PK5|PK4

EAP1=PK2|PK7 EBP1=PK6|PK3

OAPi=OAP1|KAi , OBPi=OBP1|KBi

EAPi=EAP1|KAi EBPi=EBP1|KBi

RVi,j+1=

RFOAPj|OBPj(RVi,j)?RVi,j-1 if i is odd

RFEAPj|EBPj(RVi,j)?RVi,j-1 if i is even

RKi-1=RVi,0|RVi,1 RK0 =|0|128

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