diff --git a/README.md b/README.md
index 9ef17ce..e926e00 100644
--- a/README.md
+++ b/README.md
@@ -25,12 +25,12 @@ $ pip install ubank
 Register a new passkey with ubank:
 
 ```console
-$ python -m ubank name@domain.com --output passkey.pickle
+$ python -m ubank name@domain.com --output passkey.cbor
 Enter ubank password:
 Enter security code sent to 04xxxxx789: 123456
 ```
 
-The above writes a new passkey to `passkey.pickle`.
+The above writes a new passkey to `passkey.cbor`.
 You'll be prompted for your ubank username and SMS security code.
 
 > [!CAUTION]
@@ -43,7 +43,7 @@ Use your passkey to access ubank's API in a Python script:
 from ubank import Client, Passkey
 
 # Load passkey from file.
-with open("passkey.pickle", "rb") as f:
+with open("passkey.cbor", "rb") as f:
     passkey = Passkey.load(f)
 
 # Authenticate to ubank with passkey and print account balances.
@@ -125,7 +125,7 @@ Run tests locally:
 $ uv run pytest -v
 ```
 
-`test_ubank_client` requires a valid `passkey.pickle` file for testing ubank
+`test_ubank_client` requires a valid `passkey.cbor` file for testing ubank
 authentication.
 Skip this test using the following expression:
 
@@ -146,12 +146,6 @@ Old: 2.0.0
 New: 2.1.0
 ```
 
-Update uv lockfile:
-
-```console
-$ uv lock
-```
-
 Update `test_version` test.
 
 Create version tag and push to GitHub:
diff --git a/test_ubank.py b/test_ubank.py
index e28d1d1..46142a7 100644
--- a/test_ubank.py
+++ b/test_ubank.py
@@ -15,7 +15,7 @@
 
 
 def test_version():
-    assert __version__ == "2.0.0rc0"
+    assert __version__ == "2.0.0rc1"
 
 
 def test_int8array_to_bytes():
@@ -114,7 +114,7 @@ def test_serialize_assertion():
 
 
 def test_passkey_serialization(tmp_path):
-    """Tests passkey pickle/unpickle."""
+    """Tests passkey de/serialization."""
     passkey = Passkey(passkey_name="test")
     # Passkey created with constructor should not have filename attribute.
     assert not hasattr(passkey, "filename")
@@ -154,24 +154,24 @@ def test_passkey_serialization(tmp_path):
     passkey.device_id = "abc"
     passkey.username = "123"
 
-    # Dump and unpickle passkey.
-    with (tmp_path / "pickle").open("wb") as f:
+    # Serialize and deserialize passkey.
+    with (tmp_path / "passkey.cbor").open("wb") as f:
         passkey.dump(f)
-    with (tmp_path / "pickle").open("rb") as f:
-        unpickled_passkey = Passkey.load(f)
+    with (tmp_path / "passkey.cbor").open("rb") as f:
+        deserialized_passkey = Passkey.load(f)
 
     # Passkey created with Passkey.load() should have filename attribute.
-    assert hasattr(unpickled_passkey, "filename")
+    assert hasattr(deserialized_passkey, "filename")
 
-    assert unpickled_passkey.passkey_name == passkey.passkey_name
-    assert unpickled_passkey.hardware_id == passkey.hardware_id
-    assert unpickled_passkey.device_meta == passkey.device_meta
-    assert unpickled_passkey.device_id == passkey.device_id
-    assert unpickled_passkey.username == passkey.username
+    assert deserialized_passkey.passkey_name == passkey.passkey_name
+    assert deserialized_passkey.hardware_id == passkey.hardware_id
+    assert deserialized_passkey.device_meta == passkey.device_meta
+    assert deserialized_passkey.device_id == passkey.device_id
+    assert deserialized_passkey.username == passkey.username
 
-    assert unpickled_passkey.credential_id == passkey.credential_id
-    assert unpickled_passkey.private_key != passkey.private_key
-    assert unpickled_passkey.private_key.private_bytes(
+    assert deserialized_passkey.credential_id == passkey.credential_id
+    assert deserialized_passkey.private_key != passkey.private_key
+    assert deserialized_passkey.private_key.private_bytes(
         serialization.Encoding.PEM,
         serialization.PrivateFormat.PKCS8,
         serialization.NoEncryption(),
@@ -180,16 +180,16 @@ def test_passkey_serialization(tmp_path):
         serialization.PrivateFormat.PKCS8,
         serialization.NoEncryption(),
     )
-    assert unpickled_passkey.aaguid == passkey.aaguid
-    assert unpickled_passkey.rp_id == passkey.rp_id
-    assert unpickled_passkey.user_handle == passkey.user_handle
-    assert unpickled_passkey.sign_count == passkey.sign_count
+    assert deserialized_passkey.aaguid == passkey.aaguid
+    assert deserialized_passkey.rp_id == passkey.rp_id
+    assert deserialized_passkey.user_handle == passkey.user_handle
+    assert deserialized_passkey.sign_count == passkey.sign_count
 
 
 def test_ubank_client():
     """Tests Client using passkey loaded from file."""
     # Load passkey from file.
-    with open("passkey.pickle", "rb") as f:
+    with open("passkey.cbor", "rb") as f:
         passkey = Passkey.load(f)
 
     # Authenticate to ubank with passkey.
@@ -199,6 +199,6 @@ def test_ubank_client():
             == "ubank"
         )
 
-    # Updated passkey should be pickled automatically with updated sign_count.
-    with open("passkey.pickle", "rb") as f:
+    # Updated passkey should be serialized automatically with updated sign_count.
+    with open("passkey.cbor", "rb") as f:
         assert Passkey.load(f).sign_count == passkey.sign_count
diff --git a/ubank.py b/ubank.py
index 999cd2d..d183f8f 100644
--- a/ubank.py
+++ b/ubank.py
@@ -1,7 +1,6 @@
 import argparse
 import json
 import logging
-import pickle
 import uuid
 from base64 import b64encode
 from getpass import getpass
@@ -11,7 +10,7 @@
 import soft_webauthn
 from cryptography.hazmat.primitives import serialization
 
-__version__ = "2.0.0rc0"
+__version__ = "2.0.0rc1"
 
 # Unchanging headers in every request.
 base_headers = {
@@ -173,31 +172,29 @@ def get(self, options, origin):
 
     # TODO: Replace if serialization PR merged https://github.com/bodik/soft-webauthn/pull/11
     def dump(self, file: IO[bytes]):
-        """Writes pickled passkey to `file`."""
-        serialized_passkey = Passkey(self.passkey_name)
-        for name, value in vars(self).items():
-            setattr(serialized_passkey, name, value)
-        serialized_passkey.private_key = self.private_key.private_bytes(
+        """Serializes passkey to `file`."""
+        passkey_dict = {name: value for name, value in vars(self).items()}
+        passkey_dict["private_key"] = self.private_key.private_bytes(
             serialization.Encoding.PEM,
             serialization.PrivateFormat.PKCS8,
             serialization.NoEncryption(),
         )
-        pickle.dump(serialized_passkey, file)
+        file.write(soft_webauthn.cbor.dump_dict(passkey_dict))
 
     # TODO: Replace if serialization PR merged https://github.com/bodik/soft-webauthn/pull/11
     @classmethod
     def load(cls, file: IO[bytes]):
-        """Returns passkey unpickled from `file`."""
-        serialized_passkey = pickle.load(file)
-        passkey = Passkey(serialized_passkey.passkey_name)
-        for name, value in vars(serialized_passkey).items():
+        """Deserializes passkey from `file`."""
+        passkey_dict = soft_webauthn.cbor.decode(file.read())
+        passkey = Passkey(passkey_dict["passkey_name"])
+        for name, value in passkey_dict.items():
             setattr(passkey, name, value)
         passkey.private_key = serialization.load_pem_private_key(
-            serialized_passkey.private_key,
+            passkey.private_key,
             password=None,
             backend=soft_webauthn.default_backend(),
         )
-        # Maintain reference to pickled passkey file.
+        # Maintain reference to serialized passkey filename.
         passkey.filename = file.name
         return passkey
 
diff --git a/uv.lock b/uv.lock
index ed30908..7b5ff38 100644
--- a/uv.lock
+++ b/uv.lock
@@ -245,7 +245,6 @@ wheels = [
 
 [[package]]
 name = "ubank"
-version = "2.0.0rc0"
 source = { editable = "." }
 dependencies = [
     { name = "httpx" },