diff --git a/Makefile b/Makefile
index b2d3ea7b..13f1dc25 100644
--- a/Makefile
+++ b/Makefile
@@ -140,9 +140,11 @@ DES_SRC =						ft_des_initial_permutation.c 				\
 								ft_des_generate_decryption_round_keys.c 	\
 								ft_des_parse_args.c 						\
 								ft_des_arg_parsers.c 						\
+								ft_des_usage.c 								\
 								ft_des.c 									\
 								ft_des_ecb.c 								\
 								ft_des_cbc.c 								\
+								ft_des_pcbc.c 								\
 								ft_des_init_ctx.c 							\
 								ft_des_set_raw_key.c 						\
 								ft_des_set_raw_iv.c 						\
diff --git a/inc/ft_des.h b/inc/ft_des.h
index a9510af6..5225ba3b 100644
--- a/inc/ft_des.h
+++ b/inc/ft_des.h
@@ -328,6 +328,19 @@ int									ft_des_salt_arg_parser
 	t_des_ctx *c
 );
 
+int									ft_des_help_arg_parser
+(
+	int argc,
+	char **argv,
+	int position,
+	t_des_ctx *c
+);
+
+void								ft_des_usage
+(
+	void
+);
+
 void								ft_des
 (
 	t_des_ctx *c
@@ -345,6 +358,12 @@ void								ft_des_cbc
 	char **argv
 );
 
+void								ft_des_pcbc
+(
+	int argc,
+	char **argv
+);
+
 void								ft_des_decrypt
 (
 	t_des_ctx *ctx
diff --git a/src/base64/ft_base64.c b/src/base64/ft_base64.c
index 9caa50a5..388a0929 100644
--- a/src/base64/ft_base64.c
+++ b/src/base64/ft_base64.c
@@ -5,6 +5,13 @@
 #include "libft.h"
 #include "ft_base64.h"
 
+static void	usage(void)
+{
+	ft_putstr("base64 usage:\n");
+	ft_putstr("ft_ssl base64 [-d|-e] [-i in_file] [-o out_file]\n\n");
+	exit(1);
+}
+
 static int	open_input(char *filename)
 {
 	int fd;
@@ -66,6 +73,8 @@ static void read_args
 			ctx->input_fd = open_input(next_arg);
 		else if (ft_strcmp(current_arg, "-o") == 0)
 			ctx->output_fd = open_output(next_arg);
+		else if (ft_strcmp(current_arg, "-h") == 0)
+			usage();
 		else if (++i)
 			continue;
 		i++;
diff --git a/src/des/ft_des_arg_parsers.c b/src/des/ft_des_arg_parsers.c
index ccdb36ff..0a6eee3b 100644
--- a/src/des/ft_des_arg_parsers.c
+++ b/src/des/ft_des_arg_parsers.c
@@ -147,3 +147,19 @@ int ft_des_salt_arg_parser
 	ctx->raw_salt = argv[position + 1];
 	return (position + 2);
 }
+
+int ft_des_help_arg_parser
+(
+	int argc,
+	char **argv,
+	int position,
+	t_des_ctx *ctx
+)
+{
+	(void)argc;
+	(void)argv;
+	(void)position;
+	(void)ctx;
+	ft_des_usage();
+	return (position);
+}
diff --git a/src/des/ft_des_cbc.c b/src/des/ft_des_cbc.c
index 7a91a18a..f439d213 100644
--- a/src/des/ft_des_cbc.c
+++ b/src/des/ft_des_cbc.c
@@ -2,8 +2,8 @@
 
 static void xor
 (
-	t_byte1 plaintext[FT_DES_BIT_BLOCK_SIZE],
-	t_byte1 iv[FT_DES_BIT_BLOCK_SIZE]
+	t_byte1 a[FT_DES_BIT_BLOCK_SIZE],
+	t_byte1 b[FT_DES_BIT_BLOCK_SIZE]
 )
 {
 	int i;
@@ -11,7 +11,7 @@ static void xor
 	i = 0;
 	while(i < FT_DES_BIT_BLOCK_SIZE)
 	{
-		plaintext[i] = plaintext[i] ^ iv[i];
+		a[i] = a[i] ^ b[i];
 		i++;
 	}
 }
diff --git a/src/des/ft_des_parse_args.c b/src/des/ft_des_parse_args.c
index f3e99329..9a4450e1 100644
--- a/src/des/ft_des_parse_args.c
+++ b/src/des/ft_des_parse_args.c
@@ -39,6 +39,10 @@ t_des_argument_parser	g_arg_parsers[] = {
 		"-s",
 		ft_des_salt_arg_parser,
 	},
+	{
+		"-h",
+		ft_des_help_arg_parser,
+	},
 	{ NULL, NULL},
 };
 
diff --git a/src/des/ft_des_pcbc.c b/src/des/ft_des_pcbc.c
new file mode 100644
index 00000000..60b72300
--- /dev/null
+++ b/src/des/ft_des_pcbc.c
@@ -0,0 +1,75 @@
+#include "ft_des.h"
+
+static void xor
+(
+	t_byte1 a[FT_DES_BIT_BLOCK_SIZE],
+	t_byte1 b[FT_DES_BIT_BLOCK_SIZE]
+)
+{
+	int i;
+
+	i = 0;
+	while(i < FT_DES_BIT_BLOCK_SIZE)
+	{
+		a[i] = a[i] ^ b[i];
+		i++;
+	}
+}
+
+static	void encrypt
+(
+	t_byte1 input[FT_DES_BYTE_BLOCK_SIZE],
+	t_byte1 keys[FT_DES_ROUND_COUNT][FT_DES_ROUND_KEY_SIZE],
+	t_byte1 iv[FT_DES_BYTE_BLOCK_SIZE],
+	t_byte1 output[FT_DES_BYTE_BLOCK_SIZE]
+)
+{
+	t_byte1		input_bits[FT_DES_BIT_BLOCK_SIZE];
+	t_byte1		input_with_iv[FT_DES_BYTE_BLOCK_SIZE];
+
+	ft_des_byte_to_bits(input, FT_DES_BYTE_BLOCK_SIZE, input_bits,
+		FT_DES_BIT_BLOCK_SIZE);
+	xor(iv, input_bits);
+	ft_des_bits_to_bytes(input_bits, FT_DES_BIT_BLOCK_SIZE, input_with_iv,
+		FT_DES_BYTE_BLOCK_SIZE);
+	ft_des_process_block(input_with_iv, keys, output);
+	ft_des_byte_to_bits(output, FT_DES_BYTE_BLOCK_SIZE, iv,
+		FT_DES_BIT_BLOCK_SIZE);
+	xor(iv, input_bits);
+}
+
+static	void decrypt
+(
+	t_byte1 input[FT_DES_BYTE_BLOCK_SIZE],
+	t_byte1 keys[FT_DES_ROUND_COUNT][FT_DES_ROUND_KEY_SIZE],
+	t_byte1 iv[FT_DES_BYTE_BLOCK_SIZE],
+	t_byte1 output[FT_DES_BYTE_BLOCK_SIZE]
+)
+{
+	t_byte1		output_bits[FT_DES_BIT_BLOCK_SIZE];
+
+	ft_des_process_block(input, keys, output);
+	ft_des_byte_to_bits(output, FT_DES_BYTE_BLOCK_SIZE, output_bits,
+		FT_DES_BIT_BLOCK_SIZE);
+	xor(output_bits, iv);
+	ft_des_byte_to_bits(input, FT_DES_BYTE_BLOCK_SIZE, iv,
+		FT_DES_BIT_BLOCK_SIZE);
+	xor(iv, output_bits);
+}
+
+void		ft_des_pcbc
+(
+	int argc,
+	char **argv
+)
+{
+	t_des_ctx ctx;
+
+	ft_des_init_ctx(&ctx);
+	ft_des_parse_args(argc, argv, &ctx);
+	if (ctx.raw_key && !ctx.raw_iv)
+		ft_des_print_error("initialization vector required when key specified");
+	ctx.encrypt = encrypt;
+	ctx.decrypt = decrypt;
+	ft_des(&ctx);
+}
\ No newline at end of file
diff --git a/src/des/ft_des_usage.c b/src/des/ft_des_usage.c
new file mode 100644
index 00000000..e763c22b
--- /dev/null
+++ b/src/des/ft_des_usage.c
@@ -0,0 +1,23 @@
+#include "libft.h"
+
+void	ft_des_usage
+(
+	void
+)
+{
+	ft_putstr("des cipher usage:\n\n");
+	ft_putstr("ft_ssl des-{mode} [flags]\n\n");
+	ft_putstr("flags:\n");
+	ft_putstr(" -a\t\tdecode/encode the input/output in base64\n");
+	ft_putstr(" -e\t\tecrypt mode\n");
+	ft_putstr(" -d\t\tdecrypt mode\n");
+	ft_putstr(" -i\t\tinput file for message\n");
+	ft_putstr(" -o\t\toutput file for message\n");
+	ft_putstr(" -p pass\tpassword in ascii format\n");
+	ft_putstr(" -k key\t\tkey in hex format\n");
+	ft_putstr(" -s salt\tsalt in hex format\n");
+	ft_putstr(" -v vector\tinitialization vector in hex format\n\n");
+	ft_putstr("where {mode} is one of:\n");
+	ft_putstr("ecb\ncbc\npcbc\n");
+	exit(1);
+}
\ No newline at end of file
diff --git a/src/ft_ssl_usage.c b/src/ft_ssl_usage.c
index a10807ef..dfe36a94 100644
--- a/src/ft_ssl_usage.c
+++ b/src/ft_ssl_usage.c
@@ -19,7 +19,7 @@ void	ft_ssl_usage(void)
 	ft_putstr("Message Digest commands:\n");
 	ft_putstr("md5\nsha256\nsha224\n\n");
 	ft_putstr("Cipher commands:\n");
-	ft_putstr("base64\ndes-ecb\n\n");
+	ft_putstr("base64\ndes-ecb\ndes-cbc\ndes-pcbc\n\n");
 	ft_putstr("To get help for specific command:\n");
 	ft_putstr("ft_ssl command -h\n\n");
 	exit(1);
diff --git a/src/main.c b/src/main.c
index 83f77a02..f64f82d3 100644
--- a/src/main.c
+++ b/src/main.c
@@ -42,6 +42,10 @@ t_algorithm g_algorithms[] = {
 		"des-cbc",
 		ft_des_cbc,
 	},
+	{
+		"des-pcbc",
+		ft_des_pcbc,
+	},
 	{NULL, NULL}
 };
 
diff --git a/src/md5/ft_md5.c b/src/md5/ft_md5.c
index 18c9d9ec..ae9bb749 100644
--- a/src/md5/ft_md5.c
+++ b/src/md5/ft_md5.c
@@ -15,7 +15,7 @@
 
 static void		ft_md5_usage(void)
 {
-	ft_putstr("MD5 Digest usage:\n");
+	ft_putstr("md5 digest usage:\n");
 	ft_putstr("ft_ssl md5 [-p|-q|-r] [[-s string...] [file...]]\n\n");
 	exit(1);
 }
@@ -35,6 +35,8 @@ static int		read_flags(int argc, char **argv, t_md5_flags *flags)
 	i = 1;
 	while (i < argc)
 	{
+		if (ft_strcmp("-h", argv[i]) == 0)
+			ft_md5_usage();
 		if (ft_strcmp("-r", argv[i]) == 0)
 			flags->reverse = 1;
 		else if (ft_strcmp("-q", argv[i]) == 0)
diff --git a/src/sha/ft_sha224.c b/src/sha/ft_sha224.c
index dcf0b49c..591b4990 100644
--- a/src/sha/ft_sha224.c
+++ b/src/sha/ft_sha224.c
@@ -28,6 +28,8 @@ static int		read_flags(int argc, char **argv, t_sha_flags *flags)
 	i = 1;
 	while (i < argc)
 	{
+		if (ft_strcmp("-h", argv[i]) == 0)
+			ft_sha_usage("sha224");
 		if (ft_strcmp("-r", argv[i]) == 0)
 			flags->reverse = 1;
 		else if (ft_strcmp("-q", argv[i]) == 0)
@@ -57,7 +59,7 @@ static void		process_strings_and_files
 		if (ft_strcmp("-s", argv[i]) == 0)
 		{
 			if (i + 1 >= argc)
-				ft_sha_usage("SHA224");
+				ft_sha_usage("sha224");
 			ft_sha224_string(ctx, (t_byte1 *)argv[++i], flags);
 			i++;
 		}
diff --git a/src/sha/ft_sha256.c b/src/sha/ft_sha256.c
index 3a04ddc7..9176eca4 100644
--- a/src/sha/ft_sha256.c
+++ b/src/sha/ft_sha256.c
@@ -28,6 +28,8 @@ static int		read_flags(int argc, char **argv, t_sha_flags *flags)
 	i = 1;
 	while (i < argc)
 	{
+		if (ft_strcmp("-h", argv[i]) == 0)
+			ft_sha_usage("sha256");
 		if (ft_strcmp("-r", argv[i]) == 0)
 			flags->reverse = 1;
 		else if (ft_strcmp("-q", argv[i]) == 0)
@@ -57,7 +59,7 @@ static void		process_strings_and_files
 		if (ft_strcmp("-s", argv[i]) == 0)
 		{
 			if (i + 1 >= argc)
-				ft_sha_usage("SHA256");
+				ft_sha_usage("sha256");
 			ft_sha256_string(ctx, (t_byte1 *)argv[++i], flags);
 			i++;
 		}
diff --git a/src/sha/ft_sha_usage.c b/src/sha/ft_sha_usage.c
index f771de3f..a839244b 100644
--- a/src/sha/ft_sha_usage.c
+++ b/src/sha/ft_sha_usage.c
@@ -15,7 +15,7 @@
 void		ft_sha_usage(const char *algorithm)
 {
 	ft_putstr(algorithm);
-	ft_putstr(" Digest usage:\n");
+	ft_putstr(" digest usage:\n");
 	ft_putstr("ft_ssl ");
 	ft_putstr(algorithm);
 	ft_putstr(" [-p|-q|-r] [[-s string...] [file...]]\n\n");