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Why are binary operations - such as AND, OR, XOR - used instead of S-boxes in the nonlinear F function?

What would happen if a structure like the DES F function were used instead of the current function implementation?

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  • $\begingroup$ I think we need some context. Are you asking about the abstract DES definition, a specific DES implementation, or some other cipher entirely? $\endgroup$ – poncho Jan 25 '18 at 17:50
  • $\begingroup$ I think that you meant to write "S-boxes" instead of "DES F function" in that last sentence. Please edit the question if this is correct. $\endgroup$ – Maarten Bodewes Jan 25 '18 at 18:51
  • $\begingroup$ im pretty sure s-boxes ARE used in the F function... $\endgroup$ – Richie Frame Jan 26 '18 at 4:14
  • $\begingroup$ What implementation? A software implementation using logic operations was describe in Eli Biham's A Fast New DES Implementation in Software in 1997 involving the use of SIMD processing in a 64 bit processor on 64 blocks I seem to recall Michael Kwan demonstrated implementing the S Boxes in 1998. There's a code example in John the Ripper. Logic gates are not unexpected in hardware implementations. $\endgroup$ – user1430 Jan 29 '18 at 9:40

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