diff --git a/keystore2/src/enforcements.rs b/keystore2/src/enforcements.rs
new file mode 100644
index 0000000..7f9569f
--- /dev/null
+++ b/keystore2/src/enforcements.rs
@@ -0,0 +1,50 @@
+// Copyright 2020, The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//TODO: remove this after implementing the methods.
+#![allow(dead_code)]
+
+//! This is the Keystore 2.0 Enforcements module.
+// TODO: more description to follow.
+use android_hardware_security_keymint::aidl::android::hardware::security::keymint::HardwareAuthToken::HardwareAuthToken;
+use std::collections::{HashMap, HashSet};
+use std::sync::Mutex;
+
+/// Enforcements data structure
+pub struct Enforcements {
+    // This hash set contains the user ids for whom the device is currently unlocked. If a user id
+    // is not in the set, it implies that the device is locked for the user.
+    device_unlocked_set: Mutex<HashSet<i32>>,
+    // This maps the operation challenge to an optional auth token, to maintain op-auth tokens
+    // in-memory, until they are picked up and given to the operation by authorise_update_finish().
+    op_auth_map: Mutex<HashMap<i64, Option<HardwareAuthToken>>>,
+}
+
+impl Enforcements {
+    /// Creates an enforcement object with the two data structures it holds.
+    pub fn new() -> Self {
+        Enforcements {
+            device_unlocked_set: Mutex::new(HashSet::new()),
+            op_auth_map: Mutex::new(HashMap::new()),
+        }
+    }
+}
+
+impl Default for Enforcements {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+//TODO: Add tests to enforcement module (b/175578618).
diff --git a/keystore2/src/lib.rs b/keystore2/src/lib.rs
index 6299940..45447a9 100644
--- a/keystore2/src/lib.rs
+++ b/keystore2/src/lib.rs
@@ -16,6 +16,7 @@
 
 pub mod auth_token_handler;
 pub mod database;
+pub mod enforcements;
 pub mod error;
 pub mod globals;
 /// Internal Representation of Key Parameter and convenience functions.