5.3.1 InvshiftRows (Transformation. 21 5.3.2 InvSubBytes (Transformation............... 22 5.3.3 InvMixColumns (Transformation...... 23 5.3.4 Inverse of the AddRoundKey ()Transformation. 23 5.3.5 Equivalent Inverse Cipher................... 23 6. IMPLEMENTATION ISSUES...... .25 6.1 KEY LENGTH REQUIREMENTS 25 6.3 PARAMETERIZATION OF KEY LENGTH,BLOCK SIZE,AND ROUND NUMBER. 26 6.4 IMPLEMENTATION SUGGESTIONS REGARDING VARIOUS PLATFORMS.... 26 APPENDIX A-KEY EXPANSION EXAMPLES......... 27 A.1 EXPANSION OF A 128-BIT CIPHER KEY. 27 A.2 EXPANSION OF A 192-BIT CIPHER KEY. 28 A.3 EXPANSION OF A 256-BIT CIPHER KEY.... 30 APPENDIX B-CIPHER EXAMPLE....... .33 APPENDIX C-EXAMPLE VECTORS. .35 C.1AES-128(NK=4,NR=10). 35 C.2AES-192(NK=6,NR=12) 38 C.3AES-256(NK=8,NR=14). 42 APPENDIX D-REFERENCES........ 47 22 5.3.1 InvShiftRows() Transformation ................................................................................................. 21 5.3.2 InvSubBytes() Transformation ................................................................................................... 22 5.3.3 InvMixColumns() Transformation............................................................................................... 23 5.3.4 Inverse of the AddRoundKey() Transformation............................................................................. 23 5.3.5 Equivalent Inverse Cipher .................................................................................................................. 23 6. IMPLEMENTATION ISSUES...................................................................................................................... 25 6.1 KEY LENGTH REQUIREMENTS....................................................................................................................... 25 6.2 KEYING RESTRICTIONS ................................................................................................................................. 26 6.3 PARAMETERIZATION OF KEY LENGTH, BLOCK SIZE, AND ROUND NUMBER................................................. 26 6.4 IMPLEMENTATION SUGGESTIONS REGARDING VARIOUS PLATFORMS........................................................... 26 APPENDIX A - KEY EXPANSION EXAMPLES ................................................................................................ 27 A.1 EXPANSION OF A 128-BIT CIPHER KEY.......................................................................................................... 27 A.2 EXPANSION OF A 192-BIT CIPHER KEY.......................................................................................................... 28 A.3 EXPANSION OF A 256-BIT CIPHER KEY.......................................................................................................... 30 APPENDIX B – CIPHER EXAMPLE.................................................................................................................... 33 APPENDIX C – EXAMPLE VECTORS................................................................................................................ 35 C.1 AES-128 (NK=4, NR=10).............................................................................................................................. 35 C.2 AES-192 (NK=6, NR=12).............................................................................................................................. 38 C.3 AES-256 (NK=8, NR=14).............................................................................................................................. 42 APPENDIX D - REFERENCES.............................................................................................................................. 47