diff --git a/backend/services/settingsService.js b/backend/services/settingsService.js
index 1d3bafe..10ad35a 100644
--- a/backend/services/settingsService.js
+++ b/backend/services/settingsService.js
@@ -428,14 +428,16 @@ class SettingsService extends BaseService{
             }
         }
 
-        const hasKey = Boolean(keyRow && keyRow.value && String(keyRow.value).trim());
+        const hasStoredKey = Boolean(keyRow && keyRow.getDataValue('value') && String(keyRow.getDataValue('value')).trim());
+        const hasReadableKey = Boolean(keyRow && keyRow.value && String(keyRow.value).trim());
 
         return {
             enabled: parsed.enabled !== false,
             baseUrl: parsed.baseUrl || '',
             model: parsed.model || 'gpt-4o-mini',
-            hasKey,
-            keyLast4: parsed.keyLast4 || null
+            hasKey: hasStoredKey,
+            keyLast4: parsed.keyLast4 || null,
+            keyStatus: hasStoredKey ? (hasReadableKey ? 'stored' : 'invalid') : 'missing'
         };
     }
 
diff --git a/backend/services/vocabService.js b/backend/services/vocabService.js
index cd46739..8dc01c2 100644
--- a/backend/services/vocabService.js
+++ b/backend/services/vocabService.js
@@ -12,7 +12,6 @@ import UserParam from '../models/community/user_param.js';
 import { sequelize } from '../utils/sequelize.js';
 import { notifyUser } from '../utils/socket.js';
 import { Op } from 'sequelize';
-import { decrypt } from '../utils/encryption.js';
 
 export default class VocabService {
   async _getUserByHashedId(hashedUserId) {
@@ -56,7 +55,7 @@ export default class VocabService {
       }
     }
 
-    const decryptedKey = keyRow?.value ? decrypt(keyRow.value) : null;
+    const decryptedKey = keyRow?.value ? String(keyRow.value).trim() : null;
     const hasKey = Boolean(decryptedKey && String(decryptedKey).trim());
     const enabled = parsed.enabled !== false;
     const baseUrl = String(parsed.baseUrl || '').trim();
diff --git a/frontend/src/i18n/locales/de/settings.json b/frontend/src/i18n/locales/de/settings.json
index 1f9b868..01d5439 100644
--- a/frontend/src/i18n/locales/de/settings.json
+++ b/frontend/src/i18n/locales/de/settings.json
@@ -169,7 +169,10 @@
             "save": "Speichern",
             "saved": "Einstellungen gespeichert.",
             "saveError": "Speichern fehlgeschlagen.",
-            "confirmClear": "API-Schlüssel wirklich löschen?"
+            "confirmClear": "API-Schlüssel wirklich löschen?",
+            "keyStatusStored": "API-Schlüssel gespeichert.",
+            "keyStatusInvalid": "Ein gespeicherter API-Schlüssel ist vorhanden, kann aber nicht gelesen werden. Bitte neu speichern.",
+            "keyStatusMissing": "Derzeit ist kein API-Schlüssel gespeichert."
         },
         "interests": {
             "title": "Interessen",
diff --git a/frontend/src/i18n/locales/en/settings.json b/frontend/src/i18n/locales/en/settings.json
index 053e7f0..d3a9f00 100644
--- a/frontend/src/i18n/locales/en/settings.json
+++ b/frontend/src/i18n/locales/en/settings.json
@@ -169,7 +169,10 @@
             "save": "Save",
             "saved": "Settings saved.",
             "saveError": "Could not save.",
-            "confirmClear": "Really delete the API key?"
+            "confirmClear": "Really delete the API key?",
+            "keyStatusStored": "API key stored.",
+            "keyStatusInvalid": "A stored API key exists, but it cannot be read. Please save it again.",
+            "keyStatusMissing": "No API key is currently stored."
         },
         "interests": {
             "title": "Interests",
@@ -198,4 +201,4 @@
             }
         }
     }
-}
\ No newline at end of file
+}
diff --git a/frontend/src/i18n/locales/es/settings.json b/frontend/src/i18n/locales/es/settings.json
index 09ea7f3..9055e60 100644
--- a/frontend/src/i18n/locales/es/settings.json
+++ b/frontend/src/i18n/locales/es/settings.json
@@ -169,7 +169,10 @@
             "save": "Guardar",
             "saved": "Ajustes guardados.",
             "saveError": "No se pudo guardar.",
-            "confirmClear": "¿Eliminar realmente la clave API?"
+            "confirmClear": "¿Eliminar realmente la clave API?",
+            "keyStatusStored": "Clave API guardada.",
+            "keyStatusInvalid": "Existe una clave API guardada, pero no se puede leer. Guárdala de nuevo.",
+            "keyStatusMissing": "Actualmente no hay ninguna clave API guardada."
         },
         "interests": {
             "title": "Intereses",
diff --git a/frontend/src/views/settings/LanguageAssistantView.vue b/frontend/src/views/settings/LanguageAssistantView.vue
index 4845cf4..71e7d06 100644
--- a/frontend/src/views/settings/LanguageAssistantView.vue
+++ b/frontend/src/views/settings/LanguageAssistantView.vue
@@ -51,6 +51,9 @@
                         :placeholder="apiKeyPlaceholder"
                     />
                     <span class="language-assistant-settings__hint">{{ $t('settings.languageAssistant.apiKeyHint') }}</span>
+                    <span class="language-assistant-settings__hint" :class="`language-assistant-settings__key-status language-assistant-settings__key-status--${keyStatus}`">
+                        {{ keyStatusLabel }}
+                    </span>
                 </label>
             </div>
 
@@ -84,6 +87,7 @@ export default {
             },
             hasKey: false,
             keyLast4: null,
+            keyStatus: 'missing',
             saving: false,
             loadError: null
         };
@@ -100,6 +104,14 @@ export default {
                 });
             }
             return this.$t('settings.languageAssistant.apiKeyPlaceholderNew');
+        },
+        keyStatusLabel() {
+            const statusKey = {
+                stored: 'settings.languageAssistant.keyStatusStored',
+                invalid: 'settings.languageAssistant.keyStatusInvalid',
+                missing: 'settings.languageAssistant.keyStatusMissing'
+            }[this.keyStatus] || 'settings.languageAssistant.keyStatusMissing';
+            return this.$t(statusKey);
         }
     },
     async mounted() {
@@ -115,6 +127,7 @@ export default {
                 this.form.model = data.model || 'gpt-4o-mini';
                 this.hasKey = data.hasKey;
                 this.keyLast4 = data.keyLast4;
+                this.keyStatus = data.keyStatus || (data.hasKey ? 'stored' : 'missing');
                 this.form.apiKey = '';
                 this.form.clearKey = false;
             } catch (e) {
@@ -208,6 +221,18 @@ export default {
     font-size: 0.8rem;
     opacity: 0.8;
 }
+.language-assistant-settings__key-status {
+    font-weight: 600;
+}
+.language-assistant-settings__key-status--stored {
+    color: #2e7d32;
+}
+.language-assistant-settings__key-status--invalid {
+    color: #c62828;
+}
+.language-assistant-settings__key-status--missing {
+    color: #8a6d3b;
+}
 .language-assistant-settings__toggle {
     display: flex;
     align-items: center;