diff --git a/snip/crypto/service.py b/snip/crypto/service.py
index 16dae47..605f85e 100644
--- a/snip/crypto/service.py
+++ b/snip/crypto/service.py
@@ -20,9 +20,12 @@ class CryptoService:
             key_file = os.environ.get("SNIP_KEY_FILE", "~/.snip/.key")
         self.key_file = os.path.expanduser(key_file)
         self._ensure_dir()
+        self._password = None
 
     def _ensure_dir(self):
-        os.makedirs(os.path.dirname(self.key_file), exist_ok=True)
+        key_dir = os.path.dirname(self.key_file)
+        if key_dir:
+            os.makedirs(key_dir, exist_ok=True)
 
     def _get_salt(self) -> bytes:
         salt_file = f"{self.key_file}.salt"
@@ -48,14 +51,34 @@ class CryptoService:
         key = self._derive_key(password)
         return Fernet(key)
 
-    def encrypt(self, plaintext: str, password: str) -> str:
+    def has_key(self) -> bool:
+        """Check if a password has been set."""
+        return self._password is not None
+
+    def set_password(self, password: str):
+        """Set the encryption password."""
+        self._password = password
+
+    def verify_password(self, password: str) -> bool:
+        """Verify if the given password is correct."""
+        return self._password == password
+
+    def encrypt(self, plaintext: str, password: str | None = None) -> str:
         """Encrypt plaintext using password-derived key."""
+        if password is None:
+            password = self._password
+        if password is None:
+            raise ValueError("No password set")
         f = self._get_fernet(password)
         encrypted = f.encrypt(plaintext.encode())
         return base64.urlsafe_b64encode(encrypted).decode()
 
-    def decrypt(self, ciphertext: str, password: str) -> str:
+    def decrypt(self, ciphertext: str, password: str | None = None) -> str:
         """Decrypt ciphertext using password-derived key."""
+        if password is None:
+            password = self._password
+        if password is None:
+            raise ValueError("No password set")
         f = self._get_fernet(password)
         encrypted = base64.urlsafe_b64decode(ciphertext.encode())
-        return f.decrypt(encrypted).decode()
+        return f.decrypt(encrypted).decode()
\ No newline at end of file