diff --git a/security/sharedsecret/aidl/Android.bp b/security/sharedsecret/aidl/Android.bp
new file mode 100644
index 0000000..ab44110
--- /dev/null
+++ b/security/sharedsecret/aidl/Android.bp
@@ -0,0 +1,21 @@
+aidl_interface {
+    name: "android.hardware.security.sharedsecret",
+    vendor_available: true,
+    srcs: [
+        "android/hardware/security/sharedsecret/*.aidl",
+    ],
+    stability: "vintf",
+    backend: {
+        java: {
+            sdk_version: "module_current",
+        },
+        ndk: {
+            vndk: {
+                enabled: true,
+            },
+        },
+        rust: {
+            enabled: true,
+        },
+    },
+}
diff --git a/security/sharedsecret/aidl/aidl_api/android.hardware.security.sharedsecret/current/android/hardware/security/sharedsecret/ISharedSecret.aidl b/security/sharedsecret/aidl/aidl_api/android.hardware.security.sharedsecret/current/android/hardware/security/sharedsecret/ISharedSecret.aidl
new file mode 100644
index 0000000..2509936
--- /dev/null
+++ b/security/sharedsecret/aidl/aidl_api/android.hardware.security.sharedsecret/current/android/hardware/security/sharedsecret/ISharedSecret.aidl
@@ -0,0 +1,26 @@
+///////////////////////////////////////////////////////////////////////////////
+// THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
+///////////////////////////////////////////////////////////////////////////////
+
+// This file is a snapshot of an AIDL file. Do not edit it manually. There are
+// two cases:
+// 1). this is a frozen version file - do not edit this in any case.
+// 2). this is a 'current' file. If you make a backwards compatible change to
+//     the interface (from the latest frozen version), the build system will
+//     prompt you to update this file with `m <name>-update-api`.
+//
+// You must not make a backward incompatible change to any AIDL file built
+// with the aidl_interface module type with versions property set. The module
+// type is used to build AIDL files in a way that they can be used across
+// independently updatable components of the system. If a device is shipped
+// with such a backward incompatible change, it has a high risk of breaking
+// later when a module using the interface is updated, e.g., Mainline modules.
+
+package android.hardware.security.sharedsecret;
+@VintfStability
+interface ISharedSecret {
+  android.hardware.security.sharedsecret.SharedSecretParameters getSharedSecretParameters();
+  byte[] computeSharedSecret(in android.hardware.security.sharedsecret.SharedSecretParameters[] params);
+  const String KEY_AGREEMENT_LABEL = "KeymasterSharedMac";
+  const String KEY_CHECK_LABEL = "Keymaster HMAC Verification";
+}
diff --git a/security/sharedsecret/aidl/aidl_api/android.hardware.security.sharedsecret/current/android/hardware/security/sharedsecret/SharedSecretParameters.aidl b/security/sharedsecret/aidl/aidl_api/android.hardware.security.sharedsecret/current/android/hardware/security/sharedsecret/SharedSecretParameters.aidl
new file mode 100644
index 0000000..9b65046
--- /dev/null
+++ b/security/sharedsecret/aidl/aidl_api/android.hardware.security.sharedsecret/current/android/hardware/security/sharedsecret/SharedSecretParameters.aidl
@@ -0,0 +1,24 @@
+///////////////////////////////////////////////////////////////////////////////
+// THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
+///////////////////////////////////////////////////////////////////////////////
+
+// This file is a snapshot of an AIDL file. Do not edit it manually. There are
+// two cases:
+// 1). this is a frozen version file - do not edit this in any case.
+// 2). this is a 'current' file. If you make a backwards compatible change to
+//     the interface (from the latest frozen version), the build system will
+//     prompt you to update this file with `m <name>-update-api`.
+//
+// You must not make a backward incompatible change to any AIDL file built
+// with the aidl_interface module type with versions property set. The module
+// type is used to build AIDL files in a way that they can be used across
+// independently updatable components of the system. If a device is shipped
+// with such a backward incompatible change, it has a high risk of breaking
+// later when a module using the interface is updated, e.g., Mainline modules.
+
+package android.hardware.security.sharedsecret;
+@VintfStability
+parcelable SharedSecretParameters {
+  byte[] seed;
+  byte[] nonce;
+}
diff --git a/security/sharedsecret/aidl/android/hardware/security/sharedsecret/ISharedSecret.aidl b/security/sharedsecret/aidl/android/hardware/security/sharedsecret/ISharedSecret.aidl
new file mode 100644
index 0000000..906303f
--- /dev/null
+++ b/security/sharedsecret/aidl/android/hardware/security/sharedsecret/ISharedSecret.aidl
@@ -0,0 +1,114 @@
+/*
+ * Copyright (C) 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.
+ * limitations under the License.
+ */
+
+package android.hardware.security.sharedsecret;
+import android.hardware.security.sharedsecret.SharedSecretParameters;
+
+/**
+ * Shared Secret definition.
+ *
+ * An ISharedSecret enables any service that implements this interface to establish a shared secret
+ * with one or more other services such as ISecureClock, TEE IKeymintDevice, StrongBox
+ * IKeymintDevice, etc. The shared secret is a 256-bit HMAC key and it is further used to generate
+ * secure tokens with integrity protection. There are two steps to establish a shared secret between
+ * the collaborating services:
+ *
+ * Step 1: During Android startup the system calls each service that implements this interface to
+ * get the shared secret parameters. This is done using getSharedSecretParameters method defined
+ * below.
+ * Step 2: The system lexicographically sorts the shared secret parameters received from each
+ * service and then sends these sorted parameter list to each service in a computeSharedSecret
+ * method defined below. The services individually computes the shared secret and returns back
+ * the 32 byte sharing check hash value generated by using the computed shared secret.
+ * Step 3: The system collects sharing check hash values from each service and evaluates them. If
+ * they are all equal, then the shared secret generation is considered to be successful else it is
+ * considered to have failed.
+ */
+
+@VintfStability
+interface ISharedSecret {
+    /**
+     * String used as label in the shared key derivation. See computeSharedSecret below.
+     */
+    const String KEY_AGREEMENT_LABEL = "KeymasterSharedMac";
+
+    /**
+     * String used as context in the computation of the sharingCheck. See computeSharedSecret
+     * below.
+     */
+    const String KEY_CHECK_LABEL = "Keymaster HMAC Verification";
+
+    /**
+     * This method is the first step in the process for agreeing on a shared key.  It is called by
+     * Android during startup.  The system calls it on each of the HAL instances and collects the
+     * results in preparation for the second step.
+     *
+     * @return The SharedSecretParameters to use.  As specified in the SharedSecretParameters
+     *         documentation, the seed must contain the same value in every invocation
+     *         of the method on a given device, and the nonce must return the same value for every
+     *         invocation during a boot session.
+     */
+    SharedSecretParameters getSharedSecretParameters();
+
+    /**
+     * This method is the second and final step in the process for agreeing on a shared key.  It is
+     * called by Android during startup.  The system calls it on each of the keymint services, and
+     * sends to it all of the SharedSecretParameters returned by all keymint services.
+     *
+     * This method computes the shared 32-byte HMAC key ``H'' as follows (all keymint services
+     * instances perform the same computation to arrive at the same result):
+     *
+     *     H = CKDF(key = K,
+     *              context = P1 || P2 || ... || Pn,
+     *              label = KEY_AGREEMENT_LABEL)
+     *
+     * where:
+     *
+     *     ``CKDF'' is the standard AES-CMAC KDF from NIST SP 800-108 in counter mode (see Section
+     *           5.1 of the referenced publication).  ``key'', ``context'', and ``label'' are
+     *           defined in the standard.  The counter is prefixed and length L appended, as shown
+     *           in the construction on page 12 of the standard.  The label string is UTF-8 encoded.
+     *
+     *     ``K'' is a pre-established shared secret, set up during factory reset.  The mechanism for
+     *           establishing this shared secret is implementation-defined.Any method of securely
+     *           establishing K that ensures that an attacker cannot obtain or derive its value is
+     *           acceptable.
+     *
+     *           CRITICAL SECURITY REQUIREMENT: All keys created by a IKeymintDevice instance must
+     *           be cryptographically bound to the value of K, such that establishing a new K
+     *           permanently destroys them.
+     *
+     *     ``||'' represents concatenation.
+     *
+     *     ``Pi'' is the i'th SharedSecretParameters value in the params vector. Encoding of an
+     *           SharedSecretParameters is the concatenation of its two fields, i.e. seed || nonce.
+     *
+     * Note that the label "KeymasterSharedMac" is the 18-byte UTF-8 encoding of the string.
+     *
+     * @param params is an array of SharedSecretParameters The lexicographically sorted
+     * SharedSecretParameters data returned by all keymint services when getSharedSecretParameters
+     * was called.
+     *
+     * @return sharingCheck A 32-byte value used to verify that all the keymint services have
+     *         computed the same shared HMAC key.  The sharingCheck value is computed as follows:
+     *
+     *             sharingCheck = HMAC(H, KEY_CHECK_LABEL)
+     *
+     *         The string is UTF-8 encoded, 27 bytes in length.  If the returned values of all
+     *         keymint services don't match, clients must assume that HMAC agreement
+     *         failed.
+     */
+    byte[] computeSharedSecret(in SharedSecretParameters[] params);
+}
diff --git a/security/sharedsecret/aidl/android/hardware/security/sharedsecret/SharedSecretParameters.aidl b/security/sharedsecret/aidl/android/hardware/security/sharedsecret/SharedSecretParameters.aidl
new file mode 100644
index 0000000..691b3f1
--- /dev/null
+++ b/security/sharedsecret/aidl/android/hardware/security/sharedsecret/SharedSecretParameters.aidl
@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 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.
+ */
+
+package android.hardware.security.sharedsecret;
+
+/**
+ * SharedSecretParameters holds the data used in the process of establishing a shared secret i.e.
+ * HMAC key between multiple keymint services.  These parameters are returned in by
+ * getSharedSecretParameters() and send to computeShareSecret().  See the named methods in
+ * ISharedSecret for details of usage.
+ */
+
+@VintfStability
+parcelable SharedSecretParameters {
+    /**
+     * Either empty or contains a non zero persistent value that is associated with the pre-shared
+     * HMAC agreement key.  It is either empty or 32 bytes in length.
+     */
+    byte[] seed;
+
+    /**
+     * A 32-byte value which is guaranteed to be different each time
+     * getSharedSecretParameters() is called.  Probabilistic uniqueness (i.e. random) is acceptable,
+     * though a stronger uniqueness guarantee (e.g. counter) is recommended where possible.
+     */
+    byte[] nonce;
+}