diff --git a/requirements.lock b/requirements.lock
index f762a5c..f3e21b4 100644
--- a/requirements.lock
+++ b/requirements.lock
@@ -2,6 +2,7 @@ aiohappyeyeballs==2.6.1
 aiohttp==3.12.13
 aiosignal==1.3.2
 attrs==25.3.0
+argon2-cffi==23.1.0
 base58==2.1.1
 bcrypt==4.3.0
 bech32==1.2.0
diff --git a/src/password_manager/config_manager.py b/src/password_manager/config_manager.py
index c2c23a1..18a46ab 100644
--- a/src/password_manager/config_manager.py
+++ b/src/password_manager/config_manager.py
@@ -45,6 +45,7 @@ class ConfigManager:
                 "password_hash": "",
                 "inactivity_timeout": INACTIVITY_TIMEOUT,
                 "kdf_iterations": 100_000,
+                "kdf_mode": "pbkdf2",
                 "additional_backup_path": "",
                 "backup_interval": 0,
                 "secret_mode_enabled": False,
@@ -60,6 +61,7 @@ class ConfigManager:
             data.setdefault("password_hash", "")
             data.setdefault("inactivity_timeout", INACTIVITY_TIMEOUT)
             data.setdefault("kdf_iterations", 100_000)
+            data.setdefault("kdf_mode", "pbkdf2")
             data.setdefault("additional_backup_path", "")
             data.setdefault("backup_interval", 0)
             data.setdefault("secret_mode_enabled", False)
@@ -155,6 +157,19 @@ class ConfigManager:
         config = self.load_config(require_pin=False)
         return int(config.get("kdf_iterations", 100_000))
 
+    def set_kdf_mode(self, mode: str) -> None:
+        """Persist the key derivation function mode."""
+        if mode not in ("pbkdf2", "argon2"):
+            raise ValueError("kdf_mode must be 'pbkdf2' or 'argon2'")
+        config = self.load_config(require_pin=False)
+        config["kdf_mode"] = mode
+        self.save_config(config)
+
+    def get_kdf_mode(self) -> str:
+        """Retrieve the configured key derivation function."""
+        config = self.load_config(require_pin=False)
+        return config.get("kdf_mode", "pbkdf2")
+
     def set_additional_backup_path(self, path: Optional[str]) -> None:
         """Persist an optional additional backup path in the config."""
         config = self.load_config(require_pin=False)
diff --git a/src/password_manager/manager.py b/src/password_manager/manager.py
index e631bb4..65a044f 100644
--- a/src/password_manager/manager.py
+++ b/src/password_manager/manager.py
@@ -35,6 +35,7 @@ from password_manager.entry_types import EntryType
 from utils.key_derivation import (
     derive_key_from_parent_seed,
     derive_key_from_password,
+    derive_key_from_password_argon2,
     derive_index_key,
     EncryptionMode,
 )
@@ -387,13 +388,21 @@ class PasswordManager:
                 if password is None:
                     password = prompt_existing_password("Enter your master password: ")
 
+                mode = (
+                    self.config_manager.get_kdf_mode()
+                    if getattr(self, "config_manager", None)
+                    else "pbkdf2"
+                )
                 iterations = (
                     self.config_manager.get_kdf_iterations()
                     if getattr(self, "config_manager", None)
                     else 100_000
                 )
                 print("Deriving key...")
-                seed_key = derive_key_from_password(password, iterations=iterations)
+                if mode == "argon2":
+                    seed_key = derive_key_from_password_argon2(password)
+                else:
+                    seed_key = derive_key_from_password(password, iterations=iterations)
                 seed_mgr = EncryptionManager(seed_key, fingerprint_dir)
                 print("Decrypting seed...")
                 try:
@@ -448,12 +457,20 @@ class PasswordManager:
             password = prompt_existing_password("Enter your master password: ")
 
         try:
+            mode = (
+                self.config_manager.get_kdf_mode()
+                if getattr(self, "config_manager", None)
+                else "pbkdf2"
+            )
             iterations = (
                 self.config_manager.get_kdf_iterations()
                 if getattr(self, "config_manager", None)
                 else 100_000
             )
-            seed_key = derive_key_from_password(password, iterations=iterations)
+            if mode == "argon2":
+                seed_key = derive_key_from_password_argon2(password)
+            else:
+                seed_key = derive_key_from_password(password, iterations=iterations)
             seed_mgr = EncryptionManager(seed_key, fingerprint_dir)
             self.parent_seed = seed_mgr.decrypt_parent_seed()
             seed_bytes = Bip39SeedGenerator(self.parent_seed).Generate()
diff --git a/src/requirements.txt b/src/requirements.txt
index 64539a2..396ec2c 100644
--- a/src/requirements.txt
+++ b/src/requirements.txt
@@ -31,3 +31,4 @@ httpx>=0.28.1
 requests>=2.32
 python-multipart
 orjson
+argon2-cffi
diff --git a/src/seedpass/cli.py b/src/seedpass/cli.py
index 66c1624..27776e1 100644
--- a/src/seedpass/cli.py
+++ b/src/seedpass/cli.py
@@ -462,6 +462,7 @@ def config_set(ctx: typer.Context, key: str, value: str) -> None:
             [r.strip() for r in v.split(",") if r.strip()], require_pin=False
         ),
         "kdf_iterations": lambda v: cfg.set_kdf_iterations(int(v)),
+        "kdf_mode": lambda v: cfg.set_kdf_mode(v),
         "backup_interval": lambda v: cfg.set_backup_interval(float(v)),
     }
 
diff --git a/src/tests/test_cli_config_set_extra.py b/src/tests/test_cli_config_set_extra.py
index 97af474..95abdbd 100644
--- a/src/tests/test_cli_config_set_extra.py
+++ b/src/tests/test_cli_config_set_extra.py
@@ -16,6 +16,7 @@ runner = CliRunner()
         ("additional_backup_path", "", "set_additional_backup_path", None),
         ("backup_interval", "5", "set_backup_interval", 5.0),
         ("kdf_iterations", "123", "set_kdf_iterations", 123),
+        ("kdf_mode", "argon2", "set_kdf_mode", "argon2"),
         (
             "relays",
             "wss://a.com, wss://b.com",
diff --git a/src/tests/test_kdf_modes.py b/src/tests/test_kdf_modes.py
new file mode 100644
index 0000000..ab453de
--- /dev/null
+++ b/src/tests/test_kdf_modes.py
@@ -0,0 +1,75 @@
+import bcrypt
+from pathlib import Path
+from tempfile import TemporaryDirectory
+from types import SimpleNamespace
+
+from utils.key_derivation import (
+    derive_key_from_password,
+    derive_key_from_password_argon2,
+    derive_index_key,
+)
+from password_manager.encryption import EncryptionManager
+from password_manager.vault import Vault
+from password_manager.config_manager import ConfigManager
+from password_manager.manager import PasswordManager, EncryptionMode
+
+TEST_SEED = "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about"
+TEST_PASSWORD = "pw"
+
+
+def _setup_profile(tmp: Path, mode: str):
+    argon_kwargs = dict(time_cost=1, memory_cost=8, parallelism=1)
+    if mode == "argon2":
+        seed_key = derive_key_from_password_argon2(TEST_PASSWORD, **argon_kwargs)
+    else:
+        seed_key = derive_key_from_password(TEST_PASSWORD, iterations=1)
+    EncryptionManager(seed_key, tmp).encrypt_parent_seed(TEST_SEED)
+
+    index_key = derive_index_key(TEST_SEED)
+    enc_mgr = EncryptionManager(index_key, tmp)
+    vault = Vault(enc_mgr, tmp)
+    cfg_mgr = ConfigManager(vault, tmp)
+    cfg = cfg_mgr.load_config(require_pin=False)
+    cfg["password_hash"] = bcrypt.hashpw(
+        TEST_PASSWORD.encode(), bcrypt.gensalt()
+    ).decode()
+    cfg["kdf_mode"] = mode
+    cfg["kdf_iterations"] = 1
+    cfg_mgr.save_config(cfg)
+    return cfg_mgr
+
+
+def _make_pm(tmp: Path, cfg: ConfigManager):
+    pm = PasswordManager.__new__(PasswordManager)
+    pm.encryption_mode = EncryptionMode.SEED_ONLY
+    pm.config_manager = cfg
+    pm.fingerprint_dir = tmp
+    pm.current_fingerprint = "fp"
+    pm.verify_password = lambda pw: True
+    return pm
+
+
+def test_setup_encryption_manager_kdf_modes(monkeypatch):
+    with TemporaryDirectory() as td:
+        tmp = Path(td)
+        argon_kwargs = dict(time_cost=1, memory_cost=8, parallelism=1)
+        for mode in ("pbkdf2", "argon2"):
+            path = tmp / mode
+            path.mkdir()
+            cfg = _setup_profile(path, mode)
+            pm = _make_pm(path, cfg)
+            monkeypatch.setattr(
+                "password_manager.manager.prompt_existing_password",
+                lambda *_: TEST_PASSWORD,
+            )
+            if mode == "argon2":
+                monkeypatch.setattr(
+                    "password_manager.manager.derive_key_from_password_argon2",
+                    lambda pw: derive_key_from_password_argon2(pw, **argon_kwargs),
+                )
+            monkeypatch.setattr(PasswordManager, "initialize_bip85", lambda self: None)
+            monkeypatch.setattr(
+                PasswordManager, "initialize_managers", lambda self: None
+            )
+            assert pm.setup_encryption_manager(path, exit_on_fail=False)
+            assert pm.parent_seed == TEST_SEED
diff --git a/src/tests/test_key_derivation.py b/src/tests/test_key_derivation.py
index a1ea90f..bfa0c65 100644
--- a/src/tests/test_key_derivation.py
+++ b/src/tests/test_key_derivation.py
@@ -2,6 +2,7 @@ import logging
 import pytest
 from utils.key_derivation import (
     derive_key_from_password,
+    derive_key_from_password_argon2,
     derive_index_key_seed_only,
     derive_index_key,
 )
@@ -33,3 +34,11 @@ def test_seed_only_key_deterministic():
 def test_derive_index_key_seed_only():
     seed = "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about"
     assert derive_index_key(seed) == derive_index_key_seed_only(seed)
+
+
+def test_argon2_key_deterministic():
+    pw = "correct horse battery staple"
+    k1 = derive_key_from_password_argon2(pw, time_cost=1, memory_cost=8, parallelism=1)
+    k2 = derive_key_from_password_argon2(pw, time_cost=1, memory_cost=8, parallelism=1)
+    assert k1 == k2
+    assert len(k1) == 44
diff --git a/src/utils/key_derivation.py b/src/utils/key_derivation.py
index d71b26c..091ef46 100644
--- a/src/utils/key_derivation.py
+++ b/src/utils/key_derivation.py
@@ -97,6 +97,42 @@ def derive_key_from_password(password: str, iterations: int = 100_000) -> bytes:
         raise
 
 
+def derive_key_from_password_argon2(
+    password: str,
+    *,
+    time_cost: int = 2,
+    memory_cost: int = 64 * 1024,
+    parallelism: int = 8,
+) -> bytes:
+    """Derive an encryption key from a password using Argon2id.
+
+    The defaults follow recommended parameters but omit a salt for deterministic
+    output. Smaller values may be supplied for testing.
+    """
+
+    if not password:
+        logger.error("Password cannot be empty.")
+        raise ValueError("Password cannot be empty.")
+
+    normalized = unicodedata.normalize("NFKD", password).strip().encode("utf-8")
+    try:
+        from argon2.low_level import hash_secret_raw, Type
+
+        key = hash_secret_raw(
+            secret=normalized,
+            salt=b"\x00" * 16,
+            time_cost=time_cost,
+            memory_cost=memory_cost,
+            parallelism=parallelism,
+            hash_len=32,
+            type=Type.ID,
+        )
+        return base64.urlsafe_b64encode(key)
+    except Exception as e:  # pragma: no cover - pass through errors
+        logger.error(f"Error deriving key with Argon2id: {e}", exc_info=True)
+        raise
+
+
 def derive_key_from_parent_seed(parent_seed: str, fingerprint: str = None) -> bytes:
     """
     Derives a 32-byte cryptographic key from a BIP-39 parent seed using HKDF.