diff --git a/Makefile b/Makefile
index 6698fb9b..15fa21f8 100644
--- a/Makefile
+++ b/Makefile
@@ -21,6 +21,7 @@ SRC_DIR :=						$(ROOT)/src/
 MD5_DIR :=						$(SRC_DIR)/md5/
 SHA_DIR :=						$(SRC_DIR)/sha/
 B64_DIR :=						$(SRC_DIR)/base64/
+DES_DIR :=						$(SRC_DIR)/des/
 OBJ_DIR :=						$(ROOT)/obj/
 INC_DIR :=						$(ROOT)/inc/
 LIB_DIR :=						$(ROOT)/lib/
@@ -32,10 +33,12 @@ MD5_HEADER :=					$(INC_DIR)/ft_md5.h
 SHA_HEADER :=					$(INC_DIR)/ft_sha.h
 SSL_HEADER :=					$(INC_DIR)/ft_ssl.h
 B64_HEADER :=					$(INC_DIR)/ft_base64.h
+DES_HEADER :=					$(INC_DIR)/ft_des.h
 HEADERS :=						$(MD5_HEADER)								\
 								$(SHA_HEADER)								\
 								$(SSL_HEADER)								\
-								$(B64_HEADER)
+								$(B64_HEADER)								\
+								$(DES_HEADER)
 # libraries
 
 LIBFT_DIR :=					$(LIB_DIR)libft/
@@ -99,12 +102,15 @@ BASE64_SRC =					ft_base64.c 								\
 								ft_base64_decode_transform.c 				\
 								ft_base64_decode_finish.c
 
+DES_SRC =						ft_des_initial_permutation.c
+
 SRC =							main.c										\
 								ft_ssl_usage.c
 
 SRC +=							$(MD5_SRC)									\
 								$(SHA_SRC)									\
-								$(BASE64_SRC)
+								$(BASE64_SRC)								\
+								$(DES_SRC)
 # project object files
 
 OBJ =							$(addprefix $(OBJ_DIR), $(SRC:.c=.o))
@@ -123,10 +129,14 @@ SHA_TESTS +=					$(SHA_SRC)
 BASE64_TESTS =					base64_tests.c
 BASE64_TESTS +=					$(BASE64_SRC)
 
+DES_TESTS =						des_tests.c
+DES_TESTS +=					$(DES_SRC)
+
 TEST_SRC =						tests.c
 TEST_SRC +=						$(MD5_TESTS)								\
 								$(SHA_TESTS)								\
-								$(BASE64_TESTS)
+								$(BASE64_TESTS)								\
+								$(DES_TESTS)
 
 TEST_OBJ =						$(addprefix $(OBJ_DIR), $(TEST_SRC:.c=.o))
 
@@ -207,7 +217,6 @@ re: fclean all
 
 multi:
 	$(MAKE) $(LIBFT)
-	$(MAKE) check
 	$(MAKE) $(NAME)
 
 # special stuff
@@ -216,6 +225,7 @@ vpath %.c						$(SRC_DIR)									\
 								$(MD5_DIR)									\
 								$(SHA_DIR)									\
 								$(B64_DIR)									\
+								$(DES_DIR)									\
 								$(TST_DIR)
 
 .PHONY: all check clean fclean re multi
diff --git a/inc/ft_des.h b/inc/ft_des.h
new file mode 100644
index 00000000..56f49e8b
--- /dev/null
+++ b/inc/ft_des.h
@@ -0,0 +1,26 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_des.h                                           :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: gtertysh <marvin@42.fr>                    +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2019/01/19 17:58:39 by gtertysh          #+#    #+#             */
+/*   Updated: 2019/01/19 17:59:19 by gtertysh         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#ifndef FT_DES_H
+# define FT_DES_H
+
+# define FT_DES_BIT_BLOCK_SIZE 64
+
+typedef unsigned char	t_byte1;
+
+void					ft_des_initial_permutation
+(
+	t_byte1 message[FT_DES_BIT_BLOCK_SIZE],
+	t_byte1 initial_permutation[FT_DES_BIT_BLOCK_SIZE]
+);
+
+#endif
diff --git a/inc/tests.h b/inc/tests.h
index 7c4ab775..4a1f5d83 100644
--- a/inc/tests.h
+++ b/inc/tests.h
@@ -16,5 +16,6 @@
 int md5_tests(void);
 int sha_tests(void);
 int base64_tests(void);
+int des_tests(void);
 
 #endif
diff --git a/src/des/ft_des_initial_permutation.c b/src/des/ft_des_initial_permutation.c
new file mode 100644
index 00000000..d76bea28
--- /dev/null
+++ b/src/des/ft_des_initial_permutation.c
@@ -0,0 +1,28 @@
+#include "ft_des.h"
+
+void ft_des_initial_permutation
+(
+	t_byte1 message[FT_DES_BIT_BLOCK_SIZE],
+	t_byte1 initial_permutation[FT_DES_BIT_BLOCK_SIZE]
+)
+{
+	static t_byte1 table[FT_DES_BIT_BLOCK_SIZE] = {
+		58, 50, 42, 34, 26, 18, 10, 2,
+		60, 52, 44, 36, 28, 20, 12, 4,
+		62, 54, 46, 38, 30, 22, 14, 6,
+		64, 56, 48, 40, 32, 24, 16, 8,
+		57, 49, 41, 33, 25, 17,  9, 1,
+		59, 51, 43, 35, 27, 19, 11, 3,
+		61, 53, 45, 37, 29, 21, 13, 5,
+		63, 55, 47, 39, 31, 23, 15, 7,
+	};
+	t_byte1	i;
+	
+	i = 0;
+	while(i < FT_DES_BIT_BLOCK_SIZE)
+	{
+		initial_permutation[i] = message[table[i] - 1];
+		i++;
+	}
+
+}
\ No newline at end of file
diff --git a/t/des_tests.c b/t/des_tests.c
new file mode 100644
index 00000000..4d7f23f1
--- /dev/null
+++ b/t/des_tests.c
@@ -0,0 +1,54 @@
+#include "t.h"
+#include "tests.h"
+#include "ft_des.h"
+#include "libft.h"
+
+int perform_initial_permutation()
+{
+	// all 64 bits:
+	// 00000001 00100011 01000101 01100111 10001001 10101011 11001101 11101111
+	// block contains message bits in big-endian order
+	t_byte1 message[FT_DES_BIT_BLOCK_SIZE] = (t_byte1 [FT_DES_BIT_BLOCK_SIZE]) {
+		0, 0, 0, 0, 0, 0, 0, 1,
+		0, 0, 1, 0, 0, 0, 1, 1,
+		0, 1, 0, 0, 0, 1, 0, 1,
+		0, 1, 1, 0, 0, 1, 1, 1,
+		1, 0, 0, 0, 1, 0, 0, 1,
+		1, 0, 1, 0, 1, 0, 1, 1,
+		1, 1, 0, 0, 1, 1, 0, 1,
+		1, 1, 1, 0, 1, 1, 1, 1,
+	};
+
+	// all 64 bits after initial permutation:
+	// 11001100 00000000 11001100 11111111 11110000 10101010 11110000 10101010
+	t_byte1 expect[FT_DES_BIT_BLOCK_SIZE] = (t_byte1 [FT_DES_BIT_BLOCK_SIZE]) {
+		1, 1, 0, 0, 1, 1, 0, 0,
+		0, 0, 0, 0, 0, 0, 0, 0,
+		1, 1, 0, 0, 1, 1, 0, 0,
+		1, 1, 1, 1, 1, 1, 1, 1,
+		1, 1, 1, 1, 0, 0, 0, 0,
+		1, 0, 1, 0, 1, 0, 1, 0,
+		1, 1, 1, 1, 0, 0, 0, 0,
+		1, 0, 1, 0, 1, 0, 1, 0,
+	};
+
+	t_byte1 initial_permutation[FT_DES_BIT_BLOCK_SIZE];
+
+	ft_bzero(initial_permutation, FT_DES_BIT_BLOCK_SIZE);
+
+	ft_des_initial_permutation(message, initial_permutation);
+
+	int i = 0;
+	while(i < FT_DES_BIT_BLOCK_SIZE)
+	{
+		_is(initial_permutation[i] == expect[i]);
+		i++;
+	}
+	_end("perform initial permutation");
+}
+
+int des_tests()
+{
+	_should(perform_initial_permutation);
+	return 0;
+}
\ No newline at end of file
diff --git a/t/tests.c b/t/tests.c
index e1707fbe..f2d4f867 100644
--- a/t/tests.c
+++ b/t/tests.c
@@ -18,6 +18,7 @@ int all_tests()
 	_verify("md5:", md5_tests);
 	_verify("sha:", sha_tests);
 	_verify("base64:", base64_tests);
+	_verify("des:", des_tests);
 	return 0;
 }