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----------------------------------------------------------------------- ---- ---- ---- Present - a lightweight block cipher project ---- ---- ---- ---- This file is part of the Present - a lightweight block ---- ---- cipher project ---- ---- http://www.http://opencores.org/project,present ---- ---- ---- ---- Description: ---- ---- Substitution layer of Present cipher. Simple logic. ---- ---- For more information see ---- ---- http://homes.esat.kuleuven.be/~abogdano/papers/ ---- ---- present_ches07.pdf ---- ---- To Do: ---- ---- ---- ---- Author(s): ---- ---- - Krzysztof Gajewski, gajos@opencores.org ---- ---- k.gajewski@gmail.com ---- ---- ---- ----------------------------------------------------------------------- ---- ---- ---- Copyright (C) 2013 Authors and OPENCORES.ORG ---- ---- ---- ---- This source file may be used and distributed without ---- ---- restriction provided that this copyright statement is not ---- ---- removed from the file and that any derivative work contains ---- ---- the original copyright notice and the associated disclaimer. ---- ---- ---- ---- This source file is free software; you can redistribute it ---- ---- and-or modify it under the terms of the GNU Lesser General ---- ---- Public License as published by the Free Software Foundation; ---- ---- either version 2.1 of the License, or (at your option) any ---- ---- later version. ---- ---- ---- ---- This source is distributed in the hope that it will be ---- ---- useful, but WITHOUT ANY WARRANTY; without even the implied ---- ---- warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ---- ---- PURPOSE. See the GNU Lesser General Public License for more ---- ---- details. ---- ---- ---- ---- You should have received a copy of the GNU Lesser General ---- ---- Public License along with this source; if not, download it ---- ---- from http://www.opencores.org/lgpl.shtml ---- ---- ---- ----------------------------------------------------------------------- library IEEE; use IEEE.STD_LOGIC_1164.ALL; use IEEE.STD_LOGIC_ARITH.ALL; use IEEE.STD_LOGIC_UNSIGNED.ALL; entity slayer is generic ( w_4 : integer := 4 ); port ( input : in std_logic_vector(w_4-1 downto 0); output : out std_logic_vector(w_4-1 downto 0) ); end slayer; architecture Behavioral of slayer is begin output <= x"C" when input = x"0" else x"5" when input = x"1" else x"6" when input = x"2" else x"B" when input = x"3" else x"9" when input = x"4" else x"0" when input = x"5" else x"A" when input = x"6" else x"D" when input = x"7" else x"3" when input = x"8" else x"E" when input = x"9" else x"F" when input = x"A" else x"8" when input = x"B" else x"4" when input = x"C" else x"7" when input = x"D" else x"1" when input = x"E" else x"2" when input = x"F" else "ZZZZ"; end Behavioral;