diff --git a/entity/Letter.py b/entity/Letter.py
index 829ac54..e0bcf97 100644
--- a/entity/Letter.py
+++ b/entity/Letter.py
@@ -1,7 +1,7 @@
 class Letter:
     sign = "计算得到"
     encryptType = "SM4_GCM"
-    encryptKey = "计算获得"
+    encryptKey = "计算获得" # recvPubKey 加密后的 对称加密秘钥 数据
     recvPubKey = ""
     senderPubKey = ""
 
diff --git a/tool/asymmetric/RSA.py b/tool/asymmetric/RSA.py
index 542418d..f6bdc49 100644
--- a/tool/asymmetric/RSA.py
+++ b/tool/asymmetric/RSA.py
@@ -1,9 +1,10 @@
 import base64
 import binascii
+
 from Crypto.Cipher import PKCS1_OAEP
+from Crypto.Hash import SHA256
 from Crypto.PublicKey import RSA
 from Crypto.Signature import pkcs1_15
-from Crypto.Hash import SHA256
 
 
 def generate_keys(priKeySavePath, pubKeySavePath):
@@ -20,8 +21,14 @@ def generate_keys(priKeySavePath, pubKeySavePath):
     with open(pubKeySavePath, "wb") as f:
         f.write(public_key)
 
-
-def encrypt_message(message, public_key_base64):
+"""
+输入：
+需要公私钥加解密的消息：字节类型
+公私钥：base64
+输出：
+加解密后的数据：字节类型
+"""
+def encrypt_message(message: bytes, public_key_base64):
     # 加载公钥
     public_key_bin = base64.b64decode(public_key_base64)
     public_key = RSA.import_key(public_key_bin)
@@ -29,37 +36,38 @@ def encrypt_message(message, public_key_base64):
     cipher_rsa = PKCS1_OAEP.new(public_key)
     encrypted_message = cipher_rsa.encrypt(message)
 
-    return binascii.hexlify(encrypted_message).decode('utf-8')
+    return encrypted_message
 
 
-def decrypt_message(encrypted_message, private_key_base64):
+def decrypt_message(encrypted_message: bytes, private_key_base64):
     # 加载私钥
     private_key_bin = base64.b64decode(private_key_base64)
     private_key = RSA.import_key(private_key_bin)
     # 使用私钥解密消息
     cipher_rsa = PKCS1_OAEP.new(private_key)
-    decrypted_message = cipher_rsa.decrypt(binascii.unhexlify(encrypted_message))
+    decrypted_message = cipher_rsa.decrypt(encrypted_message)
+
+    return decrypted_message
 
-    return decrypted_message.decode('utf-8')
 
-def sign_message(message, private_key_base64):
+def sign_message(message: bytes, private_key_base64):
     # 加载私钥
     private_key_bin = base64.b64decode(private_key_base64)
     private_key = RSA.import_key(private_key_bin)
     # 计算消息的哈希值
-    hash_obj = SHA256.new(message.encode('utf-8'))
+    hash_obj = SHA256.new(message)
     # 使用私钥对哈希值进行签名
     signature = pkcs1_15.new(private_key).sign(hash_obj)
 
     return binascii.hexlify(signature).decode('utf-8')
 
 
-def verify_signature(message, signature, public_key_base64):
+def verify_signature(message: bytes, signature, public_key_base64):
     # 加载公钥
     public_key_bin = base64.b64decode(public_key_base64)
     public_key = RSA.import_key(public_key_bin)
     # 计算消息的哈希值
-    hash_obj = SHA256.new(message.encode('utf-8'))
+    hash_obj = SHA256.new(message)
     # 使用公钥验证签名
     try:
         pkcs1_15.new(public_key).verify(hash_obj, binascii.unhexlify(signature))
diff --git a/tool/symmetric/SM4.py b/tool/symmetric/SM4.py
index d3d53e1..38ee3ec 100644
--- a/tool/symmetric/SM4.py
+++ b/tool/symmetric/SM4.py
@@ -1,22 +1,32 @@
+import base64
 import os
 
 from gmssl import sm4
-
-def encrypt_ecb(data, key):
+"""
+输入：
+消息或者加密后消息：字符串类型
+key：字节类型
+输出：
+消息或者加密后消息：base64的字符串类型
+"""
+
+def encrypt_ecb(data: str, key: bytes) -> str:
     cipher = sm4.CryptSM4()
-    cipher.set_key(key.encode('utf-8'), sm4.SM4_ENCRYPT)
+    cipher.set_key(key, sm4.SM4_ENCRYPT)
     encrypted_data = cipher.crypt_ecb(data.encode('utf-8'))
-    return encrypted_data.hex()
+    return base64.b64encode(encrypted_data).decode('utf-8')
+
 
-def decrypt_ecb(encrypted_hex, key):
+def decrypt_ecb(encrypted_hex: str, key: bytes) -> str:
     cipher = sm4.CryptSM4()
-    cipher.set_key(key.encode('utf-8'), sm4.SM4_DECRYPT)
+    cipher.set_key(key, sm4.SM4_DECRYPT)
     decrypted_data = cipher.crypt_ecb(bytes.fromhex(encrypted_hex))
     return decrypted_data.decode('utf-8')
 
-def encrypt_cbc_with_iv(data, key):
+
+def encrypt_cbc_with_iv(data: str, key: bytes) -> str:
     cipher = sm4.CryptSM4()
-    cipher.set_key(key.encode('utf-8'), sm4.SM4_ENCRYPT)
+    cipher.set_key(key, sm4.SM4_ENCRYPT)
 
     # 生成随机的16字节IV
     iv = os.urandom(16)
@@ -25,11 +35,13 @@ def encrypt_cbc_with_iv(data, key):
     encrypted_data = cipher.crypt_cbc(iv, data.encode('utf-8'))
 
     # 将IV和加密后的数据拼接在一起
-    return iv + encrypted_data
+    return base64.b64encode(iv + encrypted_data).decode('utf-8')
 
-def decrypt_cbc_with_iv(encrypted_bytes, key):
+
+def decrypt_cbc_with_iv(encrypted_bytes_base64: str, key) -> str:
+    encrypted_bytes = base64.b64decode(encrypted_bytes_base64)
     cipher = sm4.CryptSM4()
-    cipher.set_key(key.encode('utf-8'), sm4.SM4_DECRYPT)
+    cipher.set_key(key, sm4.SM4_DECRYPT)
 
     # 提取IV
     iv = encrypted_bytes[:16]
@@ -39,12 +51,13 @@ def decrypt_cbc_with_iv(encrypted_bytes, key):
 
     # 解密数据
     decrypted_data = cipher.crypt_cbc(iv, encrypted_data)
-    return decrypted_data.decode('utf-8')
+    return base64.b64decode(decrypted_data).decode('utf-8')
+
 
 if __name__ == "__main__":
     # 示例数据和密钥
     data = "Hello, SM4!"
-    key = "1234567890abcdef"
+    key = b"1234567890abcdef"
 
     # 加密
     encrypted_data = encrypt_ecb(data, key)
@@ -56,7 +69,7 @@ if __name__ == "__main__":
 
     # 示例数据和密钥
     data = "Hello, SM4 CBC with random IV!"
-    key = "1234567890abcdef"
+    key = b"1234567890abcdef"
 
     # 加密
     encrypted_data = encrypt_cbc_with_iv(data, key)