diff --git a/org.envirocar.app/res/values/strings_activity_login.xml b/org.envirocar.app/res/values/strings_activity_login.xml
index 22d378391..9d64779f7 100644
--- a/org.envirocar.app/res/values/strings_activity_login.xml
+++ b/org.envirocar.app/res/values/strings_activity_login.xml
@@ -30,8 +30,8 @@
     <string name="register_progress_signing_in">Registering&#8230;</string>
     <string name="error_passwords_not_matching">The passwords do not match.</string>
     <string name="error_invalid_username">This username is too short.</string>
-    <string name="error_username_contain_special">Special symbol not allowed except underscore</string>
-    <string name="error_field_weak_password">Password must contain at least one uppercase letter, one lowercase letter and one digit</string>
+    <string name="error_username_contain_special">Please enter a valid username of length greater than 6 and the special symbol is not allowed except underscore</string>
+    <string name="error_field_weak_password">The Password should be of length 8–20 characters, and it must contain at least one uppercase letter, one lowercase letter, one digit, and one special character.</string>
 
     <string name="error_username_already_in_use">This username is already in use.</string>
     <string name="error_email_already_in_use">This email is already in use.</string>
diff --git a/org.envirocar.app/src/org/envirocar/app/views/login/SignupActivity.java b/org.envirocar.app/src/org/envirocar/app/views/login/SignupActivity.java
index 8c6afff00..00e7ed57c 100644
--- a/org.envirocar.app/src/org/envirocar/app/views/login/SignupActivity.java
+++ b/org.envirocar.app/src/org/envirocar/app/views/login/SignupActivity.java
@@ -81,7 +81,7 @@ public class SignupActivity extends BaseInjectorActivity {
     private static final Logger LOG = Logger.getLogger(SignupActivity.class);
 
     private static final String EMAIL_REGEX = "^[_A-Za-z0-9-\\+]+(\\.[_A-Za-z0-9-]+)*@[A-Za-z0-9-]+(\\.[A-Za-z0-9-]+)*(\\.[A-Za-z]{2,})$";
-    private static final String PASSWORD_REGEX = "^(?=.*?[A-Z])(?=.*?[a-z])(?=.*?[0-9]).{6,}$";
+    private static final String PASSWORD_REGEX= "^(?=.*[0-9])(?=.*[a-z])(?=.*[A-Z])(?=.*[@#$%^&+=])(?=\\S+$).{8,20}$";
     private static final String USERNAME_REGEX = "^[A-Za-z0-9_-]{6,}$";
     private static final int CHECK_FORM_DELAY = 750;
     private static Drawable errorPassword;
@@ -400,7 +400,7 @@ private boolean checkPasswordValidity(String password) {
         if (password == null || password.isEmpty() || password.equals("")) {
             password1EditText.setError(getString(R.string.error_field_required), errorPassword);
             isValidPassword = false;
-        } else if (password.length() < 6) {
+        } else if (password.length() < 8) {
             password1EditText.setError(getString(R.string.error_invalid_password), errorPassword);
             isValidPassword = false;
         } else if (!Pattern.matches(PASSWORD_REGEX, password)) {