diff --git a/README.md b/README.md
index 77bcfdf..18b4ce4 100644
--- a/README.md
+++ b/README.md
@@ -1,15 +1,15 @@
-# winConnect (Windows Only)
+# winConnect
 Communicate Client-Server via Windows NamedPipe
 
 ## ToDo:
 
-- [x] Add support for sending and receiving data
-- [x] Add support for other header settings
-- [x] Add support for safe closing
-- [x] Add logging
-- [ ] Send data in chunks (if data is too large)
-- [ ] Add support for encryption
-  - [ ] simple (via char shift; and auto-pairing)
+- [x] Add support for sending and receiving data (0.1.0)
+- [x] Add support for safe closing (0.9.0)
+- [x] Add support for other header settings (0.9.0)
+- [x] Add logging (0.9.1)
+- [ ] Send data in chunks (if data is too large) (0.9.3)
+- [x] Add support for encryption (0.9.2)
+  - [x] simple (via char xor'ing; auto-pairing)
   - [ ] password (via AES and PBKDF2)
   - [ ] certificate  (via RSA)
 - [ ] Add support for multiple clients
diff --git a/examples/echo_server.py b/examples/server_echo.py
similarity index 72%
rename from examples/echo_server.py
rename to examples/server_echo.py
index 140dc8d..48cbbe7 100644
--- a/examples/echo_server.py
+++ b/examples/server_echo.py
@@ -3,9 +3,8 @@ from winConnect import WinConnectDaemon
 connector = WinConnectDaemon('test')
 # Set header settings
 # see: https://docs.python.org/3.13/library/struct.html#format-characters
-# Default: ">L"
-# >L - Big-endian long integer (header_size: 4 bytes, max_size: 4294967295)
-connector.set_header_settings(">L")
+# Default: ">H" - Big-endian unsigned short integer (header_size: 2 bytes, max_size: 65535)
+connector.set_header_settings(">H")
 
 for data in connector.listen():
     print(f"({type(data)}) {data=}")
diff --git a/examples/with_crypto/client_simple.py b/examples/with_crypto/client_simple.py
new file mode 100644
index 0000000..1ca740a
--- /dev/null
+++ b/examples/with_crypto/client_simple.py
@@ -0,0 +1,27 @@
+import sys
+
+from loguru import logger
+
+from winConnect import WinConnectClient, crypto
+
+logger.remove()
+logger.add(sys.stdout, level="DEBUG")
+
+crypt_mode = crypto.WinConnectCryptoSimple()
+
+connector = WinConnectClient('test')
+connector.set_logger(logger)
+connector.set_crypto(crypt_mode)
+
+def console():
+    with connector as conn:
+        while True:
+            i = input(":> ")
+            if i == "exit":
+                break
+            conn.send_data(i)
+            data = conn.read_pipe()
+            print(f"({type(data)}) {data=}")
+
+if __name__ == '__main__':
+    console()
diff --git a/examples/with_crypto/server_simple.py b/examples/with_crypto/server_simple.py
new file mode 100644
index 0000000..3a9d97e
--- /dev/null
+++ b/examples/with_crypto/server_simple.py
@@ -0,0 +1,21 @@
+import sys
+
+from loguru import logger
+
+from winConnect import WinConnectDaemon
+from winConnect import crypto
+
+logger.remove()
+logger.add(sys.stdout, level="DEBUG")
+
+crypt_mode = crypto.WinConnectCryptoSimple()
+
+connector = WinConnectDaemon('test')
+connector.set_logger(logger)
+connector.set_crypto(crypt_mode)
+
+for data in connector.listen():
+    print(f"({type(data)}) {data=}")
+    if data is None and connector.closed:
+        break
+    connector.send_data(data)
diff --git a/winConnect/WinConnectBase.py b/winConnect/WinConnectBase.py
index 28803fb..a6a7fb6 100644
--- a/winConnect/WinConnectBase.py
+++ b/winConnect/WinConnectBase.py
@@ -9,9 +9,11 @@ import ormsgpack
 import pywintypes
 import win32file
 
-from winConnect.errors import WinConnectErrors, WinConnectClientError
-from winConnect import exceptions
-from winConnect.utils import SimpleConvertor
+from .crypto.WinConnectCrypto import WinConnectCrypto
+from .crypto.crypto_classes import WinConnectCryptoNone
+from .errors import WinConnectErrors, WinConnectError
+from . import exceptions
+from .utils import SimpleConvertor
 
 # header: len(data) in struct.pack via header_format
 # data: action:data
@@ -19,17 +21,20 @@ from winConnect.utils import SimpleConvertor
 
 class WinConnectBase:
     init_encoding = 'utf-8'
-    init_header_format = ">L"  # Format for reading header (big-endian, unsigned long; 4 bytes)
+    init_header_format = ">H"  # Format for reading header (big-endian, unsigned long; 4 bytes)
 
     default_encoding = 'utf-8'
 
-    read_max_buffer = SimpleConvertor.to_gb(4)  # Max size of buffer for message
+    read_max_buffer = SimpleConvertor.to_gb(3)-1  # Max size via chunked messages
 
     ormsgpack_options = ormsgpack.OPT_NON_STR_KEYS | ormsgpack.OPT_NAIVE_UTC | ormsgpack.OPT_PASSTHROUGH_TUPLE # ormsgpack options
 
     def __init__(self, pipe_name: str):
         self._log = logging.getLogger(f"WinConnect:{pipe_name}")
-        self._version = 1
+        # _version:
+        # 1 - 0.9.1
+        # 2 - 0.9.2+ (with crypto)
+        self._version = 2
         self._pipe_name = r'\\.\pipe\{}'.format(pipe_name)
         self._pipe = None
         self._opened = False
@@ -42,12 +47,24 @@ class WinConnectBase:
         self._inited = False
         self._session_encoding = self.init_encoding
 
-        self._parts_buffer = None  # Buffer for parts of message (If message is too big)
+        self.__crypto = WinConnectCrypto()
+        self.__crypto.set_crypto_class(WinConnectCryptoNone())
+
+        # self._chunks = []
 
         self._lock = threading.Lock()
 
+    def set_crypto(self, crypto):
+        if self._connected:
+            raise exceptions.WinConnectConnectionAlreadyOpenException("Can't change crypto while session is active")
+        self.__crypto.set_crypto_class(crypto)
+        if not self.__crypto.test_and_load():
+            raise exceptions.WinConnectCryptoException("Crypto failed test")
+
     def set_logger(self, logger):
+        logger.debug(f"[{self._pipe_name}] Update logger")
         self._log = logger
+        self.__crypto.set_logger(logger)
 
     def _calc_body_max_size(self):
         # Max size of body: 2 ** (8 * header_size) - 1 - header_size - 1
@@ -129,8 +146,10 @@ class WinConnectBase:
             if not self._connected:
                 return None, None
             _, data = win32file.ReadFile(self._pipe, message_size)
+            if self._inited:
+                data = self.__crypto.decrypt(data)
             action, data = self.__unpack_data(data)
-            # self._log.debug(f"[{self._pipe_name}] Received message: {action=} {data=}")
+            self._log.debug(f"[{self._pipe_name}] Received message: {action=} {data=}")
             return action, data
 
     def _send_message(self, action: str, data: Any):
@@ -139,6 +158,8 @@ class WinConnectBase:
             if self.closed:
                 raise exceptions.WinConnectSessionClosedException("Session is closed")
             packed_data = self.__pack_data(action, data)
+            if self._inited:
+                packed_data = self.__crypto.encrypt(packed_data)
             message_size = len(packed_data)
             if message_size > self._body_max_size:
                 raise ValueError('Message is too big')
@@ -147,9 +168,9 @@ class WinConnectBase:
                 raise ValueError('Message is too big')
             _hfmt, _ = self.__header_settings
             header = struct.pack(_hfmt, message_size)
-            # self._log.debug(f"[{self._pipe_name}] Sending message: {action=} {data=}")
-            win32file.WriteFile(self._pipe, header)
-            win32file.WriteFile(self._pipe, packed_data)
+            packet = header + packed_data
+            self._log.debug(f"[{self._pipe_name}] Sending message: {action=} {data=}; {packet=}")
+            win32file.WriteFile(self._pipe, packet)
 
     def _send_error(self, error: WinConnectErrors, error_message: str = None):
         e = {"error": True, "code": error.value, "message": error.name, "description": error_message}
@@ -165,7 +186,7 @@ class WinConnectBase:
             case b"data":
                 return False, data
             case b"error":
-                return False, WinConnectClientError(data['code'], data['message'])
+                return False, WinConnectError(data['code'], data['message'])
             case _:
                 return self._send_error(WinConnectErrors.UNKNOWN_ACTION, f"Unknown action '{action}'")
 
@@ -179,7 +200,8 @@ class WinConnectBase:
                     'encoding': self.default_encoding,
                     'header_size': self._header_size,
                     'header_format': self._header_format,
-                    'max_buffer': self.read_max_buffer
+                    'max_buffer': self.read_max_buffer,
+                    "crypto": self.__crypto.get_info()
                 }
                 session_settings = f"set_session_settings:{json.dumps(settings)}".encode(self.init_encoding)
                 self._send_message("command", session_settings)
@@ -191,15 +213,20 @@ class WinConnectBase:
                     self._send_error(WinConnectErrors.BAD_DATA, f"JSONDecodeError: {e}")
                     return self.close()
                 if settings.get('version') != self._version:
+                    self._log.error(f"{WinConnectErrors.BAD_VERSION}")
                     self._send_error(WinConnectErrors.BAD_VERSION, f"Version mismatch")
                     return self.close()
+                if settings.get('crypto') != self.__crypto.get_info():
+                    self._log.error(f"{WinConnectErrors.BAD_CRYPTO}")
+                    self._send_error(WinConnectErrors.BAD_CRYPTO, f"Crypto mismatch")
+                    return self.close()
                 self._session_encoding = settings.get('encoding', self.default_encoding)
                 self._header_size = settings.get('header_size', self._header_size)
                 self._header_format = settings.get('header_format', self._header_format)
                 self.read_max_buffer = settings.get('max_buffer', self.read_max_buffer)
-                self._send_message("command", b"ready:")
                 return True
-            case b"ready":
+            case b"session_ready":
+                self._inited = True
                 return True
             case b"close":
                 self.close()
@@ -215,7 +242,8 @@ class WinConnectBase:
             return self._send_error(WinConnectErrors.BAD_DATA, "Unknown data type")
         if not self._parse_command(data):
             return self._send_error(WinConnectErrors.INIT_FIRST, "Server need to init session first")
-        self._inited = True
+        self._send_message("command", b"session_ready:")
+        self._parse_action(*self._read_message())
 
     def send_data(self, data):
         self._send_message("data", data)
diff --git a/winConnect/WinConnectClient.py b/winConnect/WinConnectClient.py
index 4362c55..6a41eb8 100644
--- a/winConnect/WinConnectClient.py
+++ b/winConnect/WinConnectClient.py
@@ -1,8 +1,8 @@
 import pywintypes
 import win32file
 
-from winConnect.WinConnectBase import WinConnectBase
-from winConnect.exceptions import WinConnectConnectionNoPipeException
+from .WinConnectBase import WinConnectBase
+from .exceptions import WinConnectConnectionNoPipeException
 
 
 class WinConnectClient(WinConnectBase):
@@ -30,7 +30,7 @@ class WinConnectClient(WinConnectBase):
             )
             self._opened = True
             self._connected = True
-            self._log.debug(f"Pipe '{self._pipe_name}' opened")
+            self._log.debug(f"[{self._pipe_name}] Pipe opened")
         except pywintypes.error as e:
             if e.winerror == 2:
                 exc = WinConnectConnectionNoPipeException(f"Error while opening pipe: Pipe not found")
diff --git a/winConnect/WinConnectDaemon.py b/winConnect/WinConnectDaemon.py
index ea21a6c..c974a74 100644
--- a/winConnect/WinConnectDaemon.py
+++ b/winConnect/WinConnectDaemon.py
@@ -1,16 +1,14 @@
 import win32pipe
 
-from winConnect.WinConnectBase import WinConnectBase
-from winConnect.utils import SimpleConvertor
+from .WinConnectBase import WinConnectBase
+from .crypto import WinConnectCrypto
 
 
 class WinConnectDaemon(WinConnectBase):
     # see: https://mhammond.github.io/pywin32/win32pipe__CreateNamedPipe_meth.html
     pipe_openMode = win32pipe.PIPE_ACCESS_DUPLEX  # Open mode (read/write)
     pipe_pipeMode = win32pipe.PIPE_TYPE_MESSAGE | win32pipe.PIPE_READMODE_MESSAGE | win32pipe.PIPE_WAIT  # Pipe mode (message type, message read mode, blocking mode)
-    pipe_nMaxInstances = 2  # Max number of instances
-    pipe_nOutBufferSize = SimpleConvertor.to_kb(64)  # Max size of output buffer
-    pipe_nInBufferSize = SimpleConvertor.to_kb(64)  # Max size of input buffer
+    pipe_nMaxInstances = 1  # Max number of instances
     pipe_nDefaultTimeOut = 0  # ~ ms
     pipe_sa = None  # Security attributes
 
@@ -19,13 +17,17 @@ class WinConnectDaemon(WinConnectBase):
         self.run = True
 
     def _open_pipe(self):
+        pipe_nOutBufferSize, pipe_nInBufferSize = self._body_max_size+20, self._body_max_size+20
+        self._log.debug(f"[{self._pipe_name}] Creating pipe. "
+                        f"Settings: {self.pipe_openMode=}, {self.pipe_pipeMode=}, {self.pipe_nMaxInstances=}, "
+                        f"{pipe_nOutBufferSize=}, {pipe_nInBufferSize=}, {self.pipe_nDefaultTimeOut=}, {self.pipe_sa=}")
         self._pipe = win32pipe.CreateNamedPipe(
             self._pipe_name,
             self.pipe_openMode,
             self.pipe_pipeMode,
             self.pipe_nMaxInstances,
-            self.pipe_nOutBufferSize,
-            self.pipe_nInBufferSize,
+            pipe_nOutBufferSize,
+            pipe_nInBufferSize,
             self.pipe_nDefaultTimeOut,
             self.pipe_sa
         )
diff --git a/winConnect/__init__.py b/winConnect/__init__.py
index c3da51b..e812505 100644
--- a/winConnect/__init__.py
+++ b/winConnect/__init__.py
@@ -1,4 +1,6 @@
 from .WinConnectDaemon import WinConnectDaemon
 from .WinConnectClient import WinConnectClient
 
+from . import crypto
+
 from .__meta__ import *
diff --git a/winConnect/__meta__.py b/winConnect/__meta__.py
index 64957c2..4cc7390 100644
--- a/winConnect/__meta__.py
+++ b/winConnect/__meta__.py
@@ -3,8 +3,8 @@
 __title__ = 'winConnect'
 __description__ = 'Communicate Client-Server via Windows NamedPipe.'
 __url__ = 'https://github.com/SantaSpeen/winConnect'
-__version__ = '0.9.1'
-__build__ = 16
+__version__ = '0.9.2'
+__build__ = 39
 __author__ = 'SantaSpeen'
 __author_email__ = 'admin@anidev.ru'
 __license__ = "MIT"
diff --git a/winConnect/crypto/WinConnectCrypto.py b/winConnect/crypto/WinConnectCrypto.py
new file mode 100644
index 0000000..03a33f9
--- /dev/null
+++ b/winConnect/crypto/WinConnectCrypto.py
@@ -0,0 +1,48 @@
+import logging
+
+from .crypto_class_base import WinConnectCryptoBase
+from winConnect.exceptions import (
+    WinConnectCryptoBadModeException,
+    WinConnectCryptoException,
+)
+
+def test_crypto_class(crypto_class: "WinConnectCryptoBase"):
+    if not isinstance(crypto_class, WinConnectCryptoBase):
+        raise WinConnectCryptoBadModeException("crypto_class must be a subclass of WinConnectCryptoBase")
+    if not crypto_class.test():
+        raise WinConnectCryptoException("crypto_class failed test (test_bytes != decrypt_bytes)")
+
+class WinConnectCrypto:
+
+    def __init__(self):
+        self.__crypto_class = None
+        self.__log_prefix = None
+        self._log = logging.getLogger("WinConnectCrypto")
+
+    def set_crypto_class(self, crypto_class: "WinConnectCryptoBase"):
+        self._log.debug(f"{self.__log_prefix}Updating crypto class. {self.get_info()} -> {crypto_class.__class__.__name__}")
+        test_crypto_class(crypto_class)
+        self.__crypto_class = crypto_class
+        self.__log_prefix = f"[{self.get_info()}] "
+        self._log.debug(f"{self.__log_prefix}Crypto class updated.")
+
+    def set_logger(self, logger):
+        logger.debug(f"{self.__log_prefix}Setting logger")
+        self._log = logger
+
+    def test_and_load(self) -> bool:
+        self._log.debug(f"{self.__log_prefix}Testing and loading crypto class")
+        if not self.__crypto_class.test():
+            return False
+        self.__crypto_class.load()
+        self._log.debug(f"{self.__log_prefix}Crypto class loaded")
+        return True
+
+    def get_info(self):
+        return self.__crypto_class.__class__.__name__
+
+    def encrypt(self, data: bytes) -> bytes:
+        return self.__crypto_class.encrypt(data)
+
+    def decrypt(self, data: bytes) -> bytes:
+        return self.__crypto_class.decrypt(data)
diff --git a/winConnect/crypto/__init__.py b/winConnect/crypto/__init__.py
new file mode 100644
index 0000000..079eca7
--- /dev/null
+++ b/winConnect/crypto/__init__.py
@@ -0,0 +1,8 @@
+from .WinConnectCrypto import WinConnectCrypto
+from .crypto_classes import (
+    WinConnectCryptoBase,
+    WinConnectCryptoNone,
+    WinConnectCryptoSimple,
+    # WinConnectCryptoPassword,
+    # WinConnectCryptoCert
+)
diff --git a/winConnect/crypto/crypto_class_base.py b/winConnect/crypto/crypto_class_base.py
new file mode 100644
index 0000000..baab3d1
--- /dev/null
+++ b/winConnect/crypto/crypto_class_base.py
@@ -0,0 +1,14 @@
+class WinConnectCryptoBase:
+
+    def encrypt(self, data: bytes) -> bytes: ...
+    def decrypt(self, data: bytes) -> bytes: ...
+
+    def test(self, test_bytes: bytes = b"test_string") -> bool:
+        encrypted = self.encrypt(test_bytes)
+        decrypted = self.decrypt(encrypted)
+        if decrypted != test_bytes:
+            return False
+        return True
+
+    def load(self) -> None: ...
+    def unload(self) -> None: ...
diff --git a/winConnect/crypto/crypto_classes.py b/winConnect/crypto/crypto_classes.py
new file mode 100644
index 0000000..1579b55
--- /dev/null
+++ b/winConnect/crypto/crypto_classes.py
@@ -0,0 +1,70 @@
+import random
+
+from .crypto_class_base import WinConnectCryptoBase
+from winConnect.exceptions import WinConnectCryptoSimpleBadHeaderException
+
+
+class WinConnectCryptoNone(WinConnectCryptoBase):
+    def __init__(self): ...
+    def encrypt(self, data: bytes) -> bytes:
+        return data
+    def decrypt(self, data: bytes) -> bytes:
+        return data
+
+class WinConnectCryptoSimple(WinConnectCryptoBase):
+    def __init__(self):
+        pass
+
+    def encrypt(self, data: bytes) -> bytes:
+        shift_key = random.randint(100, 749)
+        key = random.randint(5, 250)
+        encrypted_text = bytearray()
+        header = f"wccs{shift_key}{key+shift_key}:"
+        for char in header:
+            encrypted_text.append(ord(char))
+        for char in data:
+            encrypted_text.append(char ^ key)
+        return bytes(encrypted_text)
+
+    def decrypt(self, data: bytes) -> bytes:
+        try:
+            header, content = data.split(b":", 1)
+            if header[:4] != b"wccs":
+                raise WinConnectCryptoSimpleBadHeaderException("Bad header in message.")
+        except ValueError:
+            raise WinConnectCryptoSimpleBadHeaderException("No header in message.")
+        shift_key = int(header[4:7])
+        key = int(header[7:]) - shift_key
+        decrypted_text = bytearray()
+        for char in content:
+            decrypted_text.append(char ^ key)
+        return bytes(decrypted_text)
+
+
+class WinConnectCryptoPassword(WinConnectCryptoBase):
+
+    def __init__(self, password: str):
+        pass
+
+    def encrypt(self, data: bytes) -> bytes:
+        pass
+
+    def decrypt(self, data: bytes) -> bytes:
+        pass
+
+class WinConnectCryptoCert(WinConnectCryptoBase):
+    def __init__(self, cert_file: str):
+        pass
+
+    def _open_cert(self):
+        pass
+
+    def load(self) -> None:
+        self._open_cert()
+
+    def encrypt(self, data: bytes) -> bytes:
+        pass
+
+    def decrypt(self, data: bytes) -> bytes:
+        pass
+
diff --git a/winConnect/errors.py b/winConnect/errors.py
index 1e79b1a..377a194 100644
--- a/winConnect/errors.py
+++ b/winConnect/errors.py
@@ -14,11 +14,13 @@ class WinConnectErrors(Enum):
     BAD_DATA = 50
     BAD_VERSION = 51
     BAD_HEADER = 52
+    BAD_BODY = 53
+    BAD_CRYPTO = 54
 
     BODY_TOO_BIG = 60
 
 
 @dataclass
-class WinConnectClientError:
+class WinConnectError:
     code: WinConnectErrors
     message: str
diff --git a/winConnect/exceptions.py b/winConnect/exceptions.py
index e04484b..433bc2c 100644
--- a/winConnect/exceptions.py
+++ b/winConnect/exceptions.py
@@ -31,3 +31,26 @@ class WinConnectSessionAlreadyActiveException(WinConnectBaseException): ...
 
 class WinConnectSessionClosedException(WinConnectBaseException): ...
 
+# Crypto
+
+class WinConnectCryptoException(WinConnectBaseException): ...
+
+class WinConnectCryptoBadModeException(WinConnectCryptoException): ...
+
+## Simple
+
+class WinConnectCryptoSimpleBadHeaderException(WinConnectCryptoException): ...
+
+## key
+class WinConnectCryptoKeyRequiredException(WinConnectCryptoException): ...
+
+class WinConnectCryptoKeyInvalidException(WinConnectCryptoException): ...
+
+## cert
+class WinConnectCryptoCertificationRequiredException(WinConnectCryptoException): ...
+
+class WinConnectCryptoCertificationNotFoundException(WinConnectCryptoException): ...
+
+class WinConnectCryptoCertificationInvalidException(WinConnectCryptoException): ...
+
+