diff --git a/sender/sender.py b/sender/sender.py
index 0535295..2831a8e 100644
--- a/sender/sender.py
+++ b/sender/sender.py
@@ -15,6 +15,7 @@ def sendLetter(letter: Letter, target="192.168.195.162:8426"):
     # 向目标ip和端口发送指定的信件
     pass
 
+
 # 选择对称加密的方法和模式(aes/sm2)
 def selectSymEncryptionChoice():
     encryWay = ""
@@ -47,18 +48,27 @@ def selectSymEncryptionChoice():
 
 
 # 使用对称加密，返回加密后的数据和随机生成的密钥
-def SymEncryption():
-
+def SymEncryption(encryData, key: bytes = None):
     # 获得加密的方法和加密的模式
     way, mode = selectSymEncryptionChoice()
 
     if way == "aes":
-        aesUtils = AESUtils()
-        encryptedData, key = aesUtils.encrypt("test", mode=mode) # 这里data要改为文件内容
+        aesUtils = AESUtils(key)
+        # tureKey 为 真实返回的Key，如果没有设置初始值，那么key是随机生成
+        encryptedData, tureKey = aesUtils.encrypt(encryData, mode=mode)  # 这里encryData要改为文件内容
         return encryptedData
 
     if way == "sm2":
         pass
 
+
 def getKey():
     pass
+
+
+if __name__ == "__main__":
+    # 示例数据和密钥
+    data = "Hello, AES!"
+    key = "1234567890abcdef"
+
+    SymEncryption(data)