diff --git a/src/backend/core/services/search_indexers.py b/src/backend/core/services/search_indexers.py
index a4bb9eec..3b064753 100644
--- a/src/backend/core/services/search_indexers.py
+++ b/src/backend/core/services/search_indexers.py
@@ -244,7 +244,12 @@ class SearchIndexer(BaseDocumentIndexer):
         """
         doc_path = document.path
         doc_content = document.content
-        text_content = utils.base64_yjs_to_text(doc_content) if doc_content else ""
+
+        # Encrypted content is ciphertext and it should never be indexed for search
+        if document.is_encrypted:
+            text_content = ""
+        else:
+            text_content = utils.base64_yjs_to_text(doc_content) if doc_content else ""
 
         return {
             "id": str(document.id),
diff --git a/src/backend/core/tests/test_services_search_indexers.py b/src/backend/core/tests/test_services_search_indexers.py
index 61488a92..f9fe7414 100644
--- a/src/backend/core/tests/test_services_search_indexers.py
+++ b/src/backend/core/tests/test_services_search_indexers.py
@@ -239,6 +239,18 @@ def test_services_search_indexers_serialize_document_empty():
     assert result["title"] == ""
 
 
+@pytest.mark.usefixtures("indexer_settings")
+def test_services_search_indexers_serialize_document_encrypted():
+    """Encrypted documents should have empty content to avoid indexing ciphertext."""
+    document = factories.DocumentFactory(is_encrypted=True)
+
+    indexer = SearchIndexer()
+    result = indexer.serialize_document(document, {})
+
+    assert result["content"] == ""
+    assert result["size"] == 0
+
+
 @responses.activate
 def test_services_search_indexers_index_errors(indexer_settings):
     """