diff --git a/Readme.md b/Readme.md
index 3330307..f96dc10 100644
--- a/Readme.md
+++ b/Readme.md
@@ -42,8 +42,8 @@ python scripts/main.py --mode cleanup --file-types encrypted
 
 ## decrypt
 
-### decrypt automatic (todo)
-To decrypt the data for a defined user type in:
+### decrypt automatic
+To decrypt the data type in:
 
 ```bash 
 python scripts/main.py --mode decrypt
@@ -64,7 +64,7 @@ python scripts/main.py --mode decrypt --user "<<user_id>>"
 python scripts/main.py --amount 3 --quota 50 --mode encrypt --add-user-information --master-password "{{master_password}}"
 ```
 
-### encrypt master-password fuile
+### encrypt master-password file
 
 ## todo 
 - add data-input attribut
diff --git a/scripts/classes/Cleanup.py b/scripts/classes/Cleanup.py
index 5eb5829..ed98aed 100644
--- a/scripts/classes/Cleanup.py
+++ b/scripts/classes/Cleanup.py
@@ -8,7 +8,7 @@ class Cleanup():
     def getAllFilePaths(self,file_type):
         all_file_paths = [
             self.paths.getGroupFilesFolderPath(file_type),
-            self.paths.getUserFilesFolderPath(file_type),
+            self.paths.getUserFilesPath(file_type),
             self.paths.getAccumulatedFilePath(file_type)
             ]
         if file_type == Paths.TYPE_DECRYPTED:
diff --git a/scripts/classes/Decryption.py b/scripts/classes/Decryption.py
index 9ac85db..02b5d71 100644
--- a/scripts/classes/Decryption.py
+++ b/scripts/classes/Decryption.py
@@ -1,6 +1,10 @@
 import json
+import os
 from pathlib import Path
 
+class AutomaticIdentificationImpossibleException(Exception):
+    pass
+
 class Decryption():
     
     def __init__(self,cli,paths):
@@ -9,6 +13,18 @@ class Decryption():
         self.cli = cli
         self.paths = paths
     
+    def identifyUser(self):
+        file_type = self.paths.TYPE_ENCRYPTED
+        file_names = next(os.walk(self.paths.getUserFilesPath(file_type)), (None, None, []))[2]
+        users = []
+        user_file_suffix = self.paths.getUserFileSuffix(file_type)
+        for file in file_names:
+            if user_file_suffix in file:
+                users.append(file.replace(user_file_suffix, ''))
+        if len(users) < 2:
+            return users[0]
+        raise AutomaticIdentificationImpossibleException()        
+            
     def initializeUser(self,user_id):
         self.user_id=str(user_id)
         self.user_file_decrypted_path = self.paths.getUserFilePath(self.user_id,self.paths.TYPE_DECRYPTED)
diff --git a/scripts/classes/Paths.py b/scripts/classes/Paths.py
index 68b3969..1ac5063 100644
--- a/scripts/classes/Paths.py
+++ b/scripts/classes/Paths.py
@@ -16,7 +16,7 @@ class Paths():
     def getGroupFilesFolderPath(self,folder_type):
         return self.getDataFolderPath(folder_type) + "group_files/"
     
-    def getUserFilesFolderPath(self,folder_type):
+    def getUserFilesPath(self,folder_type):
         return self.getDataFolderPath(folder_type) + "user_files/"
     
     def getEncryptedMainDataFile(self):
@@ -29,9 +29,12 @@ class Paths():
         if file_type == Paths.TYPE_ENCRYPTED:
             return '.gpg'
         return ''
+
+    def getUserFileSuffix(self,file_type):
+        return '.json' + self.getFileExtension(file_type)
     
     def getUserFilePath(self,user_id,file_type):
-        return self.getUserFilesFolderPath(file_type)+user_id+'.json' + self.getFileExtension(file_type);
+        return self.getUserFilesPath(file_type) + user_id + self.getUserFileSuffix(file_type);
     
     def getGroupFilePath(self,group_id,file_type):
         return self.getGroupFilesFolderPath(file_type) + str(group_id) + '.txt' + self.getFileExtension(file_type);
diff --git a/scripts/main.py b/scripts/main.py
index d01c5a9..f59b347 100644
--- a/scripts/main.py
+++ b/scripts/main.py
@@ -1,7 +1,7 @@
 import argparse
 from classes.Encryption import Encryption
 from classes.Cleanup import Cleanup
-from classes.Decryption import Decryption
+from classes.Decryption import Decryption, AutomaticIdentificationImpossibleException
 from getpass import getpass
 import traceback
 from classes.Cli import Cli
@@ -61,9 +61,16 @@ try:
         if args.mode == 'decrypt':
             decrypt = Decryption(cli,paths)
             if args.master_password is None:
-                if args.user is None: 
-                    print("Type in the user id:")
-                    decrypt.initializeUser(input())
+                if args.user is None:
+                    try:
+                        print("Attempt to identify user.") 
+                        user_id = decrypt.identifyUser()
+                        print("The user id is: " + user_id)
+                    except:
+                        print("A automatic user id identification wasn't possible.")
+                        print("Type in the user id:")
+                        user_id = input()
+                    decrypt.initializeUser(user_id)
                 else:
                     decrypt.initializeUser(args.user)
                 if args.user_password is None: