diff --git a/security/authgraph/aidl/Android.bp b/security/authgraph/aidl/Android.bp
new file mode 100644
index 0000000..373d0c4
--- /dev/null
+++ b/security/authgraph/aidl/Android.bp
@@ -0,0 +1,47 @@
+// Copyright (C) 2023 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 {
+    // See: http://go/android-license-faq
+    // A large-scale-change added 'default_applicable_licenses' to import
+    // all of the 'license_kinds' from "hardware_interfaces_license"
+    // to get the below license kinds:
+    //   SPDX-license-identifier-Apache-2.0
+    default_applicable_licenses: ["hardware_interfaces_license"],
+}
+
+aidl_interface {
+    name: "android.hardware.security.authgraph",
+    vendor_available: true,
+    srcs: [
+        "android/hardware/security/authgraph/*.aidl",
+    ],
+    stability: "vintf",
+    frozen: false,
+    backend: {
+        java: {
+            platform_apis: true,
+        },
+        ndk: {
+            apps_enabled: false,
+        },
+        rust: {
+            enabled: true,
+            apex_available: [
+                "//apex_available:platform",
+                "com.android.virt",
+            ],
+        },
+    },
+}
diff --git a/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/Arc.aidl b/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/Arc.aidl
new file mode 100644
index 0000000..dc86fbd
--- /dev/null
+++ b/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/Arc.aidl
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+///////////////////////////////////////////////////////////////////////////////
+// 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.authgraph;
+/* @hide */
+@RustDerive(Clone=true, Eq=true, PartialEq=true) @VintfStability
+parcelable Arc {
+  byte[] arc;
+}
diff --git a/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/Error.aidl b/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/Error.aidl
new file mode 100644
index 0000000..1a78b54
--- /dev/null
+++ b/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/Error.aidl
@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+///////////////////////////////////////////////////////////////////////////////
+// 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.authgraph;
+/* @hide */
+@Backing(type="int") @VintfStability
+enum Error {
+  OK = 0,
+  INVALID_PEER_NONCE = (-1) /* -1 */,
+  INVALID_PEER_KE_KEY = (-2) /* -2 */,
+  INVALID_IDENTITY = (-3) /* -3 */,
+  INVALID_CERT_CHAIN = (-4) /* -4 */,
+  INVALID_SIGNATURE = (-5) /* -5 */,
+  INVALID_KE_KEY = (-6) /* -6 */,
+  INVALID_PUB_KEY_IN_KEY = (-7) /* -7 */,
+  INVALID_PRIV_KEY_ARC_IN_KEY = (-8) /* -8 */,
+  INVALID_SHARED_KEY_ARCS = (-9) /* -9 */,
+  MEMORY_ALLOCATION_FAILED = (-10) /* -10 */,
+  INCOMPATIBLE_PROTOCOL_VERSION = (-11) /* -11 */,
+}
diff --git a/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/IAuthGraphKeyExchange.aidl b/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/IAuthGraphKeyExchange.aidl
new file mode 100644
index 0000000..2c56f33
--- /dev/null
+++ b/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/IAuthGraphKeyExchange.aidl
@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+///////////////////////////////////////////////////////////////////////////////
+// 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.authgraph;
+/* @hide */
+@VintfStability
+interface IAuthGraphKeyExchange {
+  android.hardware.security.authgraph.SessionInitiationInfo create();
+  android.hardware.security.authgraph.KeInitResult init(in android.hardware.security.authgraph.PubKey peerPubKey, in android.hardware.security.authgraph.Identity peerId, in byte[] peerNonce, in int peerVersion);
+  android.hardware.security.authgraph.SessionInfo finish(in android.hardware.security.authgraph.PubKey peerPubKey, in android.hardware.security.authgraph.Identity peerId, in android.hardware.security.authgraph.SessionIdSignature peerSignature, in byte[] peerNonce, in int peerVersion, in android.hardware.security.authgraph.Key ownKey);
+  android.hardware.security.authgraph.Arc[2] authenticationComplete(in android.hardware.security.authgraph.SessionIdSignature peerSignature, in android.hardware.security.authgraph.Arc[2] sharedKeys);
+}
diff --git a/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/Identity.aidl b/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/Identity.aidl
new file mode 100644
index 0000000..bd5453e
--- /dev/null
+++ b/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/Identity.aidl
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+///////////////////////////////////////////////////////////////////////////////
+// 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.authgraph;
+@RustDerive(Clone=true, Eq=true, PartialEq=true) @VintfStability
+parcelable Identity {
+  byte[] identity;
+}
diff --git a/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/KeInitResult.aidl b/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/KeInitResult.aidl
new file mode 100644
index 0000000..8c91523
--- /dev/null
+++ b/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/KeInitResult.aidl
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+///////////////////////////////////////////////////////////////////////////////
+// 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.authgraph;
+@RustDerive(Clone=true, Eq=true, PartialEq=true) @VintfStability
+parcelable KeInitResult {
+  android.hardware.security.authgraph.SessionInitiationInfo sessionInitiationInfo;
+  android.hardware.security.authgraph.SessionInfo sessionInfo;
+}
diff --git a/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/Key.aidl b/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/Key.aidl
new file mode 100644
index 0000000..5b4ebbf
--- /dev/null
+++ b/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/Key.aidl
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+///////////////////////////////////////////////////////////////////////////////
+// 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.authgraph;
+@RustDerive(Clone=true, Eq=true, PartialEq=true) @VintfStability
+parcelable Key {
+  @nullable android.hardware.security.authgraph.PubKey pubKey;
+  @nullable android.hardware.security.authgraph.Arc arcFromPBK;
+}
diff --git a/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/PlainPubKey.aidl b/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/PlainPubKey.aidl
new file mode 100644
index 0000000..f070bfa
--- /dev/null
+++ b/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/PlainPubKey.aidl
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+///////////////////////////////////////////////////////////////////////////////
+// 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.authgraph;
+@RustDerive(Clone=true, Eq=true, PartialEq=true) @VintfStability
+parcelable PlainPubKey {
+  byte[] plainPubKey;
+}
diff --git a/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/PubKey.aidl b/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/PubKey.aidl
new file mode 100644
index 0000000..4c3376e
--- /dev/null
+++ b/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/PubKey.aidl
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+///////////////////////////////////////////////////////////////////////////////
+// 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.authgraph;
+@RustDerive(Clone=true, Eq=true, PartialEq=true) @VintfStability
+union PubKey {
+  android.hardware.security.authgraph.PlainPubKey plainKey;
+  android.hardware.security.authgraph.SignedPubKey signedKey;
+}
diff --git a/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/SessionIdSignature.aidl b/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/SessionIdSignature.aidl
new file mode 100644
index 0000000..6dabc0a
--- /dev/null
+++ b/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/SessionIdSignature.aidl
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+///////////////////////////////////////////////////////////////////////////////
+// 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.authgraph;
+@RustDerive(Clone=true, Eq=true, PartialEq=true) @VintfStability
+parcelable SessionIdSignature {
+  byte[] signature;
+}
diff --git a/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/SessionInfo.aidl b/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/SessionInfo.aidl
new file mode 100644
index 0000000..427962b
--- /dev/null
+++ b/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/SessionInfo.aidl
@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+///////////////////////////////////////////////////////////////////////////////
+// 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.authgraph;
+@RustDerive(Clone=true, Eq=true, PartialEq=true) @VintfStability
+parcelable SessionInfo {
+  android.hardware.security.authgraph.Arc[2] sharedKeys;
+  byte[] sessionId;
+  android.hardware.security.authgraph.SessionIdSignature signature;
+}
diff --git a/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/SessionInitiationInfo.aidl b/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/SessionInitiationInfo.aidl
new file mode 100644
index 0000000..bf55e74
--- /dev/null
+++ b/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/SessionInitiationInfo.aidl
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+///////////////////////////////////////////////////////////////////////////////
+// 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.authgraph;
+@RustDerive(Clone=true, Eq=true, PartialEq=true) @VintfStability
+parcelable SessionInitiationInfo {
+  android.hardware.security.authgraph.Key key;
+  android.hardware.security.authgraph.Identity identity;
+  byte[] nonce;
+  int version;
+}
diff --git a/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/SignedPubKey.aidl b/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/SignedPubKey.aidl
new file mode 100644
index 0000000..3dbaed8
--- /dev/null
+++ b/security/authgraph/aidl/aidl_api/android.hardware.security.authgraph/current/android/hardware/security/authgraph/SignedPubKey.aidl
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+///////////////////////////////////////////////////////////////////////////////
+// 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.authgraph;
+@RustDerive(Clone=true, Eq=true, PartialEq=true) @VintfStability
+parcelable SignedPubKey {
+  byte[] signedPubKey;
+}
diff --git a/security/authgraph/aidl/android/hardware/security/authgraph/Arc.aidl b/security/authgraph/aidl/android/hardware/security/authgraph/Arc.aidl
new file mode 100644
index 0000000..855ce5c
--- /dev/null
+++ b/security/authgraph/aidl/android/hardware/security/authgraph/Arc.aidl
@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 2023 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.authgraph;
+
+/**
+ * This is the definition of the data format of an Arc.
+ * @hide
+ */
+@VintfStability
+@RustDerive(Clone=true, Eq=true, PartialEq=true)
+parcelable Arc {
+    /**
+     * The messages exchanged between the domains in the AuthGraph protocol are called Arcs.
+     * An arc is simply AES-GCM. Encryption of a payload P with a key K and additional
+     * authentication data (AAD) D: (i.e. Arc = Enc(K, P, D)).
+     *
+     * Data is CBOR-encoded according to the `Arc` CDDL definition in Arc.cddl.
+     */
+    byte[] arc;
+}
diff --git a/security/authgraph/aidl/android/hardware/security/authgraph/Arc.cddl b/security/authgraph/aidl/android/hardware/security/authgraph/Arc.cddl
new file mode 100644
index 0000000..4c1b965
--- /dev/null
+++ b/security/authgraph/aidl/android/hardware/security/authgraph/Arc.cddl
@@ -0,0 +1,115 @@
+;
+; Copyright (C) 2023 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.
+;
+Arc = [                            ; COSE_Encrypt0 [RFC9052 s5.2]
+    protected : bstr .cbor ArcProtectedHeaders,
+    unprotected : {
+        5 : bstr .size 12          ; IV
+    },
+    ciphertext : bstr    ; Enc(K, bstr .cbor Payload, encoded ArcEncStruct)
+]
+
+ArcProtectedHeaders = {
+           1 : 3,                  ; Algorithm: AES-GCM mode w/ 256-bit key, 128-bit tag
+    ? -70001 : { + Permission }, ; One or more Permissions
+    ? -70002 : { + Limitation }, ; One or more Limitations
+    ? -70003 : int,   ; Timestamp in milliseconds since some starting point (generally
+                      ; the most recent device boot) which all of the applications within
+                      ; the secure domain must agree upon
+    ? -70004 : bstr .size 16,      ; Nonce used in key exchange methods
+    ? -70005 : PayloadType,        ; Payload type, if needed to disambiguate, when processing an arc
+    ? -70006 : int,                ; Version of the payload structure (if applicable)
+    ? -70007 : int,                ; Sequence number (if needed to prevent replay attacks)
+    ? -70008 : Direction           ; Direction of the encryption key (i.e. whether it is used to
+                                   ; encrypt incoming messages or outgoing messages)
+    ? -70009 : bool,               ; "authentication_completed" - this is used during authenticated
+                                   ; key exchange indicate whether signature verification is done
+    ? -70010 : bstr .size 32       ; "session_id" computed during key exchange protocol
+}
+
+; Permissions indicate what an arc can be used with. Permissions are added to an arc during the
+; `create()` primitive operation and are propagated during `mint` and `snap` primitive operations.
+Permission = &(
+    -4770552 : IdentityEncoded,  ; "source_id" - in the operations performed by a source, the
+                                 ; source adds its own identity to the permissions of an arc.
+    -4770553 : IdentityEncoded,  ; "sink_id" - in the operations performed by a sink, the sink
+                                 ; adds its own identity to the permissions of an arc.
+    -4770555 : [ +IdentityEncoded ]  ; "minting_allowed" - defines the set of TA identities
+                                     ; to whom the payload key is allowed to be minted.
+    -4770556 : bool                  ; "deleted_on_biometric_change" - A Boolean value that
+                                     ; indicates whether an auth key issued from a biometric TA is
+                                     ; invalidated on new biometric enrollment or removal of all
+                                     ; biometrics.
+)
+
+; Limitations indicate what restrictions are applied on the usage of an arc. Permissions are added
+; to an arc during the `create` primitive operation and are propagated during `snap` primitive
+; operation.
+Limitation = &(
+    -4770554 : bstr,      ; "challenge" - is added to an arc that transfers an auth key to a channel
+                          ; key, in order to ensure the freshness of the authentication.
+                          ; A challenge is issued by a sink (e.g. Keymint TA, Biometric TAs).
+)
+
+; INCLUDE Identity.cddl for: Identity
+IdentityEncoded = bstr .cbor Identity
+
+Direction = &(
+    In:  1,
+    Out: 2,
+)
+
+PayloadType = &(
+    SecretKey: 1,
+    Arc: 2,
+    ; Any other payload types should also be defined here
+)
+
+Payload = &(
+    SecretKey,
+    Arc,
+    ; Any other payload formats should also be defined here
+)
+
+SecretKey = &(                     ; One of the payload types of an Arc is a secret key
+    SymmetricKey,
+    ECPrivateKey,    ; Private key of a key pair generated for key exchange
+)
+
+ECPrivateKey = {              ; COSE_Key [RFC9052 s7]
+    1 : 2,                    ; Key type : EC2
+    3 : -25,                  ; Algorithm: ECDH ES w/ HKDF 256 - generate key directly
+ ?  4 : [7],                  ; Key_ops: [derive key]
+   -1 : 1,                    ; Curve: P-256
+ ? -2 : bstr,                 ; x coordinate
+ ? -3 : bstr,                 ; y coordinate
+   -4 : bstr,                 ; private key (d)
+}
+
+SymmetricKey = {              ; COSE_Key [RFC9052 s7] - For symmetric key encryption
+    1 : 4,                    ; Key type : Symmetric
+    3 : 3,                    ; Algorithm : AES-GCM mode w/ 256-bit key, 128-bit tag
+    4 : [ 4 ],                ; Key_ops: [decrypt]
+   -1 : bstr .size 32,        ; Key value (k)
+}
+
+ArcEncStruct = [              ; COSE_Enc_structure [RFC9052 s5.3]
+    context   : "Encrypt0",
+    protected : bstr .cbor ArcProtectedHeaders,
+    external_aad : bstr .size 0,
+]
+
+; INCLUDE generateCertificateRequestV2.cddl for: PubKeyEd25519, PubKeyECDSA256, PubKeyECDSA384
+; from hardware/interfaces/security/rkp/aidl/android/hardware/security/keymint/
diff --git a/security/authgraph/aidl/android/hardware/security/authgraph/DicePolicy.cddl b/security/authgraph/aidl/android/hardware/security/authgraph/DicePolicy.cddl
new file mode 100644
index 0000000..a7dcbc6
--- /dev/null
+++ b/security/authgraph/aidl/android/hardware/security/authgraph/DicePolicy.cddl
@@ -0,0 +1,33 @@
+;
+; Copyright (C) 2023 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.
+;
+DicePolicy = [
+    1, ; dice policy version
+    + nodeConstraintList ; for each entry in dice chain
+]
+
+nodeConstraintList = [
+    * nodeConstraint
+]
+
+; We may add a hashConstraint item later
+nodeConstraint = exactMatchConstraint / geConstraint
+
+exactMatchConstraint = [1, keySpec, value]
+geConstraint = [2, keySpec, int]
+
+keySpec = [value+]
+
+value = bool / int / tstr / bstr
\ No newline at end of file
diff --git a/security/authgraph/aidl/android/hardware/security/authgraph/Error.aidl b/security/authgraph/aidl/android/hardware/security/authgraph/Error.aidl
new file mode 100644
index 0000000..1ad6054
--- /dev/null
+++ b/security/authgraph/aidl/android/hardware/security/authgraph/Error.aidl
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2023 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.authgraph;
+
+/**
+ * AuthGraph error codes. Aidl will return these error codes as service specific errors in
+ * EX_SERVICE_SPECIFIC.
+ * @hide
+ */
+@VintfStability
+@Backing(type="int")
+enum Error {
+    /* Success */
+    OK = 0,
+    /* Invalid peer nonce for key exchange */
+    INVALID_PEER_NONCE = -1,
+    /* Invalid key exchange public key by the peer */
+    INVALID_PEER_KE_KEY = -2,
+    /* Invalid identity of the peer */
+    INVALID_IDENTITY = -3,
+    /* Invalid certificate chain in the identity of the peer */
+    INVALID_CERT_CHAIN = -4,
+    /* Invalid signature by the peer */
+    INVALID_SIGNATURE = -5,
+    /* Invalid key exchange key created by a particular party themselves to be used as a handle */
+    INVALID_KE_KEY = -6,
+    /* Invalid public key in the `Key` struct */
+    INVALID_PUB_KEY_IN_KEY = -7,
+    /* Invalid private key arc in the `Key` struct */
+    INVALID_PRIV_KEY_ARC_IN_KEY = -8,
+    /* Invalid shared key arcs */
+    INVALID_SHARED_KEY_ARCS = -9,
+    /* Memory allocation failed */
+    MEMORY_ALLOCATION_FAILED = -10,
+    /* The protocol version negotiated with the sink is incompatible */
+    INCOMPATIBLE_PROTOCOL_VERSION = -11,
+}
diff --git a/security/authgraph/aidl/android/hardware/security/authgraph/ExplicitKeyDiceCertChain.cddl b/security/authgraph/aidl/android/hardware/security/authgraph/ExplicitKeyDiceCertChain.cddl
new file mode 100644
index 0000000..3de5617
--- /dev/null
+++ b/security/authgraph/aidl/android/hardware/security/authgraph/ExplicitKeyDiceCertChain.cddl
@@ -0,0 +1,30 @@
+;
+; Copyright (C) 2023 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.
+;
+ExplicitKeyDiceCertChain = [
+    1, ; version, hopefully will never change
+    DiceCertChainInitialPayload,
+    * DiceChainEntry
+]
+
+DiceCertChainInitialPayload = {
+    -4670552 : bstr .cbor PubKeyEd25519 /
+               bstr .cbor PubKeyECDSA256 /
+               bstr .cbor PubKeyECDSA384 ; subjectPublicKey
+}
+
+; INCLUDE generateCertificateRequestV2.cddl for: PubKeyEd25519, PubKeyECDSA256, PubKeyECDSA384,
+;                                                DiceChainEntry
+; from hardware/interfaces/security/rkp/aidl/android/hardware/security/keymint/
diff --git a/security/authgraph/aidl/android/hardware/security/authgraph/IAuthGraphKeyExchange.aidl b/security/authgraph/aidl/android/hardware/security/authgraph/IAuthGraphKeyExchange.aidl
new file mode 100644
index 0000000..6ceb09c
--- /dev/null
+++ b/security/authgraph/aidl/android/hardware/security/authgraph/IAuthGraphKeyExchange.aidl
@@ -0,0 +1,216 @@
+/*
+ * Copyright (C) 2023 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.authgraph;
+
+import android.hardware.security.authgraph.Arc;
+import android.hardware.security.authgraph.Identity;
+import android.hardware.security.authgraph.KeInitResult;
+import android.hardware.security.authgraph.Key;
+import android.hardware.security.authgraph.PubKey;
+import android.hardware.security.authgraph.SessionIdSignature;
+import android.hardware.security.authgraph.SessionInfo;
+import android.hardware.security.authgraph.SessionInitiationInfo;
+
+/**
+ * AuthGraph interface definition for authenticated key exchange between two parties: P1 (source)
+ * and P2 (sink).
+ * Pre-requisites: each participant should have a:
+ *     1. Persistent identity - e.g. a signing key pair with a self signed certificate or a DICE
+ *        certificate chain.
+ *     2. A symmetric encryption key kept in memory with per-boot life time of the participant
+ *        (a.k.a per-boot key)
+ *
+ * ErrorCodes are defined in android.hardware.security.authgraph.ErrorCode.aidl.
+ * @hide
+ */
+@VintfStability
+interface IAuthGraphKeyExchange {
+    /**
+     * This method is invoked on P1 (source).
+     * Create an ephermeral EC key pair on NIST curve P-256 and a nonce (of 16 bytes) for
+     * key exchange.
+     *
+     * @return SessionInitiationInfo including the `Key` containing the public key of the created
+     * key pair and an arc from the per-boot key to the private key, the nonce, the persistent
+     * identity and the latest protocol version (i.e. AIDL version) supported.
+     *
+     * Note: The arc from the per-boot key to the private key in `Key` of the return type:
+     * `SessionInitiationInfo` serves two purposes:
+     * i. A mapping to correlate `create` and `finish` calls to P1 in a particular instance of the
+     *    key exchange protocol.
+     * ii.A way to minimize the in-memory storage (P1 can include the nonce in the protected headers
+     *    of the arc).
+     * However, P1 should maintain some form of in-memory record to be able to verify that the input
+     * `Key` sent to `finish` is from an unfinished instance of a key exchange protocol, to prevent
+     * any replay attacks in `finish`.
+     */
+    SessionInitiationInfo create();
+
+    /**
+     * This method is invoked on P2 (sink).
+     * Perform the following steps for key exchange:
+     *     0. If either `peerPubKey`, `peerId`, `peerNonce` is not in the expected format, return
+     *        errors: INVALID_PEER_KE_KEY, INVALID_IDENTITY, INVALID_PEER_NONCE respectively.
+     *     1. Create an ephemeral EC key pair on NIST curve P-256.
+     *     2. Create a nonce (of 16 bytes).
+     *     3. Compute the diffie-hellman shared secret: Z.
+     *     4. Compute a salt = bstr .cbor [
+     *            source_version:    int,                    ; from input `peerVersion`
+     *            sink_pub_key:      bstr .cbor PlainPubKey, ; from step #1
+     *            source_pub_key:    bstr .cbor PlainPubKey, ; from input `peerPubKey`
+     *            sink_nonce:        bstr .size 16,          ; from step #2
+     *            source_nonce:      bstr .size 16,          ; from input `peerNonce`
+     *            sink_cert_chain:   bstr .cbor ExplicitKeyDiceCertChain, ; from own identity
+     *            source_cert_chain: bstr .cbor ExplicitKeyDiceCertChain, ; from input `peerId`
+     *        ]
+     *     5. Extract a cryptographic secret S from Z, using the salt from #4 above.
+     *     6. Derive two symmetric encryption keys of 256 bits with:
+     *        i. b"KE_ENCRYPTION_KEY_SOURCE_TO_SINK" as context for the key used to encrypt incoming
+     *           messages
+     *       ii. b"KE_ENCRYPTION_KEY_SINK_TO_SOURCE" as context for the key used to encrypt outgoing
+     *           messages
+     *     7. Create arcs from the per-boot key to each of the two shared keys from step #6 and
+     *        mark authentication_complete = false in arcs' protected headers.
+     *     8. Derive a MAC key with b"KE_HMAC_KEY" as the context.
+     *     9. Compute session_id_input = bstr .cbor [
+     *            sink_nonce:     bstr .size 16,
+     *            source_nonce:   bstr .size 16,
+     *        ],
+     *     10.Compute a session_id as a 256 bits HMAC over the session_id_input from step#9 with
+     *        the key from step #8.
+     *     11.Create a signature over the session_id from step #10, using the signing key which is
+     *        part of the party's identity.
+     *
+     * @param peerPubKey - the public key of the key pair created by the peer (P1) for key exchange
+     *
+     * @param peerId - the persistent identity of the peer
+     *
+     * @param peerNonce - nonce created by the peer
+     *
+     * @param peerVersion - an integer representing the latest protocol version (i.e. AIDL version)
+     *                      supported by the peer
+     *
+     * @return KeInitResult including the `Key` containing the public key of the created key pair,
+     * the nonce, the persistent identity, two shared key arcs from step #7, session id, signature
+     * over the session id and the negotiated protocol version. The negotiated protocol version
+     * should be less than or equal to the peer's version.
+     *
+     * Note: The two shared key arcs in the return type: `KeInitResult` serves two purposes:
+     * i. A mapping to correlate `init` and `authenticationComplete` calls to P2 in a particular
+     *    instance of the key exchange protocol.
+     * ii.A way to minimize the in-memory storage of P2 allocated for key exchange.
+     * However, P2 should maintain some in-memory record to be able to verify that the input
+     * `sharedkeys` sent to `authenticationComplete` and to any subsequent AuthGraph protocol
+     * methods are valid shared keys agreed with the party identified by `peerId`, to prevent
+     * any replay attacks in `authenticationComplete` and in any subsequent AuthGraph protocol
+     * methods which use the shared keys to encrypt the secret messages.
+     */
+    KeInitResult init(
+            in PubKey peerPubKey, in Identity peerId, in byte[] peerNonce, in int peerVersion);
+
+    /**
+     * This method is invoked on P1 (source).
+     * Perform the following steps:
+     *     0. If either `peerPubKey`, `peerId`, `peerNonce` is not in the expected format, return
+     *        errors: INVALID_PEER_KE_KEY, INVALID_IDENTITY, INVALID_PEER_NONCE respectively. If
+     *        `peerVersion` is greater than the version advertised in `create`, return error:
+     *        INCOMPATIBLE_PROTOCOL_VERSION.
+     *        If `ownKey` is not in the in-memory records for unfinished instances of a key
+     *        exchange protocol, return error: INVALID_KE_KEY. Similarly, if the public key or the
+     *        arc containing the private key in `ownKey` is invalid, return INVALID_PUB_KEY_IN_KEY
+     *        and INVALID_PRIV_KEY_ARC_IN_KEY respectively.
+     *     1. Compute the diffie-hellman shared secret: Z.
+     *     2. Compute a salt = bstr .cbor [
+     *            source_version:    int,                    ; the protocol version used in `create`
+     *            sink_pub_key:      bstr .cbor PlainPubKey, ; from input `peerPubKey`
+     *            source_pub_key:    bstr .cbor PlainPubKey, ; from the output of `create`
+     *            sink_nonce:        bstr .size 16,          ; from input `peerNonce`
+     *            source_nonce:      bstr .size 16,          ; from the output of `create`
+     *            sink_cert_chain:   bstr .cbor ExplicitKeyDiceCertChain, ; from input `peerId`
+     *            source_cert_chain: bstr .cbor ExplicitKeyDiceCertChain, ; from own identity
+     *        ]
+     *     3. Extract a cryptographic secret S from Z, using the salt from #2 above.
+     *     4. Derive two symmetric encryption keys of 256 bits with:
+     *        i. b"KE_ENCRYPTION_KEY_SOURCE_TO_SINK" as context for the key used to encrypt outgoing
+     *           messages
+     *       ii. b"KE_ENCRYPTION_KEY_SINK_TO_SOURCE" as context for the key used to encrypt incoming
+     *           messages
+     *     5. Derive a MAC key with b"KE_HMAC_KEY" as the context.
+     *     6. Compute session_id_input = bstr .cbor [
+     *            sink_nonce:     bstr .size 16,
+     *            source_nonce:   bstr .size 16,
+     *        ],
+     *     7. Compute a session_id as a 256 bits HMAC over the session_id_input from step #6 with
+     *        the key from step #5.
+     *     8. Verify the peer's signature over the session_id from step #7. If successful, proceed,
+     *        otherwise, return error: INVALID_SIGNATURE.
+     *     9. Create arcs from the per-boot key to each of the two shared keys from step #4 and
+     *        mark authentication_complete = true in arcs' protected headers.
+     *     10.Create a signature over the session_id from step #7, using the signing key which is
+     *        part of the party's identity.
+     *
+     * @param peerPubKey - the public key of the key pair created by the peer (P2) for key exchange
+     *
+     * @param peerId - the persistent identity of the peer
+     *
+     * @param peerSignature - the signature created by the peer over the session id computed by the
+     *                        peer
+     *
+     * @param peerNonce - nonce created by the peer
+     *
+     * @param peerVersion - an integer representing the protocol version (i.e. AIDL version)
+     *                      negotiated with the peer
+     *
+     * @param ownKey - the key created by P1 (source) in `create()` for key exchange
+     *
+     * @return SessionInfo including the two shared key arcs from step #9, session id and the
+     * signature over the session id.
+     *
+     * Note: The two shared key arcs in the return type: `SessionInfo` serves two purposes:
+     * i. A mapping to correlate the key exchange protocol taken place with a particular peer and
+     *    subsequent AuthGraph protocols execued with the same peer.
+     * ii.A way to minimize the in-memory storage for shared keys.
+     * However, P1 should maintain some in-memory record to be able to verify that the shared key
+     * arcs sent to any subsequent AuthGraph protocol methods are valid shared keys agreed with the
+     * party identified by `peerId`, to prevent any replay attacks.
+     */
+    SessionInfo finish(in PubKey peerPubKey, in Identity peerId,
+            in SessionIdSignature peerSignature, in byte[] peerNonce, in int peerVersion,
+            in Key ownKey);
+
+    /**
+     * This method is invoked on P2 (sink).
+     * Perform the following steps:
+     *   0. If input `sharedKeys` is invalid (i.e. they cannot be decrypted with P2's per-boot key
+     *      or they are not in P2's in-memory records as valid shared keys agreed with the party
+     *      identified by `peerId`), return error: INVALID_SHARED_KEY_ARCS.
+     *   1. Verify that both shared key arcs have the same session id and peer identity.
+     *   2. Verify the peer's signature over the session id attached to the shared key arcs'
+     *      headers. If successful, proceed, otherwise, return error: INVALID_SIGNATURE.
+     *   3. Mark authentication_complete = true in the shared key arcs' headers
+     *
+     * @param peerSignature - the signature created by the peer over the session id computed by the
+     *                        peer
+     *
+     * @param sharedKeys - two shared key arcs created by P2 in `init`. P2 obtains from the arcs'
+     *                     protected headers, the session id and the peer's identity to verify the
+     *                     peer's signature over the session id.
+     *
+     * @return Arc[] - an array of two updated shared key arcs
+     */
+    Arc[2] authenticationComplete(in SessionIdSignature peerSignature, in Arc[2] sharedKeys);
+}
diff --git a/security/authgraph/aidl/android/hardware/security/authgraph/Identity.aidl b/security/authgraph/aidl/android/hardware/security/authgraph/Identity.aidl
new file mode 100644
index 0000000..9e350e8
--- /dev/null
+++ b/security/authgraph/aidl/android/hardware/security/authgraph/Identity.aidl
@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) 2023 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.authgraph;
+
+/**
+ * Persistent (versioned) identity of a participant of Authgraph key exchange.
+ * Identity consists of two main parts:
+ *     1. a certificate chain (e.g. a DICE certificate chain)
+ *     2. (optional) a policy specifying how to verify the certificate chain - if a policy is not
+ *        provided, a simple byte-to-byte comparison of the certificate chain is assumed.
+ *
+ * During identity verification, the certificate chain of the identity attached to the access
+ * request is compared against the policy of the identity attached to the persistent resources.
+ *
+ * The usage of policy based identity verification in Authgraph is three-fold:
+ *        1. Retain access to persistent resources for the newer versions of the party who
+ *           created them, even when parts of the certificate chain are updated in the new version.
+ *        2. Deny access to the new persistent resources for the older versions of the party
+ *           who created the new persistent resources.
+ *        3. Trigger rotation of critical keys encrypted in persistent arcs created by the previous
+ *           version of the party, by including an updated policy in the identity attached to the
+ *           access request.
+ */
+@VintfStability
+@RustDerive(Clone=true, Eq=true, PartialEq=true)
+parcelable Identity {
+    /* Data is CBOR-encoded according to the `Identity` CDDL definition in Identity.cddl */
+    byte[] identity;
+}
diff --git a/security/authgraph/aidl/android/hardware/security/authgraph/Identity.cddl b/security/authgraph/aidl/android/hardware/security/authgraph/Identity.cddl
new file mode 100644
index 0000000..0419421
--- /dev/null
+++ b/security/authgraph/aidl/android/hardware/security/authgraph/Identity.cddl
@@ -0,0 +1,23 @@
+;
+; Copyright (C) 2023 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.
+;
+Identity = [
+    1, ; Version
+    cert_chain: bstr .cbor ExplicitKeyDiceCertChain,
+    policy: bstr .cbor DicePolicy / nil,
+]
+
+; INCLUDE ExplicitKeyDiceCertChain.cddl for: ExplicitKeyDiceCertChain
+; INCLUDE DicePolicy.cddl for: DicePolicy
diff --git a/security/authgraph/aidl/android/hardware/security/authgraph/KeInitResult.aidl b/security/authgraph/aidl/android/hardware/security/authgraph/KeInitResult.aidl
new file mode 100644
index 0000000..b4ae451
--- /dev/null
+++ b/security/authgraph/aidl/android/hardware/security/authgraph/KeInitResult.aidl
@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2023 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.authgraph;
+
+import android.hardware.security.authgraph.SessionInfo;
+import android.hardware.security.authgraph.SessionInitiationInfo;
+
+/**
+ * The return type for the init() step of authenticated key exchange.
+ */
+@VintfStability
+@RustDerive(Clone=true, Eq=true, PartialEq=true)
+parcelable KeInitResult {
+    /**
+     * Session initiation information.
+     */
+    SessionInitiationInfo sessionInitiationInfo;
+
+    /**
+     * Session information.
+     */
+    SessionInfo sessionInfo;
+}
diff --git a/security/authgraph/aidl/android/hardware/security/authgraph/Key.aidl b/security/authgraph/aidl/android/hardware/security/authgraph/Key.aidl
new file mode 100644
index 0000000..11fe174
--- /dev/null
+++ b/security/authgraph/aidl/android/hardware/security/authgraph/Key.aidl
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2023 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.authgraph;
+
+import android.hardware.security.authgraph.Arc;
+import android.hardware.security.authgraph.PubKey;
+
+/**
+ * The type that encapsulates a key. Key can be either a symmetric key or an asymmetric key.
+ * If it is an asymmetric key, it is used for key exchange.
+ */
+@VintfStability
+@RustDerive(Clone=true, Eq=true, PartialEq=true)
+parcelable Key {
+    /**
+     * If the Key is an asymmetric key, public key should be present.
+     */
+    @nullable PubKey pubKey;
+
+    /**
+     * Arc from the per-boot key to the payload key. The payload key is either the symmetric key
+     * or the private key of an asymmetric key, based on the type of the key being created.
+     * This is marked as optional because there are instances where only the public key is returned,
+     * e.g. `init` method in the key exchange protocol.
+     */
+    @nullable Arc arcFromPBK;
+}
diff --git a/security/authgraph/aidl/android/hardware/security/authgraph/PlainPubKey.aidl b/security/authgraph/aidl/android/hardware/security/authgraph/PlainPubKey.aidl
new file mode 100644
index 0000000..5483ec5
--- /dev/null
+++ b/security/authgraph/aidl/android/hardware/security/authgraph/PlainPubKey.aidl
@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2023 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.authgraph;
+
+/**
+ * One of the two enum variants of the enum type: `PubKey`. This represents the plain public key
+ * material encoded as a COSE_Key.
+ */
+@VintfStability
+@RustDerive(Clone=true, Eq=true, PartialEq=true)
+parcelable PlainPubKey {
+    /* Data is CBOR-encoded according to the `PlainPubKey` CDDL definition in PlainPubKey.cddl */
+    byte[] plainPubKey;
+}
diff --git a/security/authgraph/aidl/android/hardware/security/authgraph/PlainPubKey.cddl b/security/authgraph/aidl/android/hardware/security/authgraph/PlainPubKey.cddl
new file mode 100644
index 0000000..34b316b
--- /dev/null
+++ b/security/authgraph/aidl/android/hardware/security/authgraph/PlainPubKey.cddl
@@ -0,0 +1,24 @@
+;
+; Copyright (C) 2023 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.
+;
+
+; P-256 public key for key exchange.
+PlainPubKey = [ ; COSE_Key [RFC9052 s7]
+    1 : 2,                       ; Key type : EC2
+    3 : -27,                     ; Algorithm : ECDH-SS + HKDF-256
+    -1 : 1,                      ; Curve: P256
+    -2 : bstr,                   ; X coordinate, big-endian
+    -3 : bstr                    ; Y coordinate, big-endian
+]
diff --git a/security/authgraph/aidl/android/hardware/security/authgraph/PubKey.aidl b/security/authgraph/aidl/android/hardware/security/authgraph/PubKey.aidl
new file mode 100644
index 0000000..8640871
--- /dev/null
+++ b/security/authgraph/aidl/android/hardware/security/authgraph/PubKey.aidl
@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2023 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.authgraph;
+
+import android.hardware.security.authgraph.PlainPubKey;
+import android.hardware.security.authgraph.SignedPubKey;
+
+/**
+ * The enum type representing the public key of an asymmetric key pair.
+ */
+@VintfStability
+@RustDerive(Clone=true, Eq=true, PartialEq=true)
+union PubKey {
+    /**
+     * Plain public key material encoded as a COSE_Key.
+     */
+    PlainPubKey plainKey;
+
+    /**
+     * Public key signed with the long term signing key of the party.
+     */
+    SignedPubKey signedKey;
+}
diff --git a/security/authgraph/aidl/android/hardware/security/authgraph/SessionIdSignature.aidl b/security/authgraph/aidl/android/hardware/security/authgraph/SessionIdSignature.aidl
new file mode 100644
index 0000000..2fa8b4c
--- /dev/null
+++ b/security/authgraph/aidl/android/hardware/security/authgraph/SessionIdSignature.aidl
@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2023 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.authgraph;
+
+/**
+ * Signature computed by a party over the session id during authenticated key exchange.
+ */
+@VintfStability
+@RustDerive(Clone=true, Eq=true, PartialEq=true)
+parcelable SessionIdSignature {
+    /* Data is CBOR-encoded according to the `SessionIdSignature` CDDL definition in
+     * SessionIdSignature.cddl */
+    byte[] signature;
+}
diff --git a/security/authgraph/aidl/android/hardware/security/authgraph/SessionIdSignature.cddl b/security/authgraph/aidl/android/hardware/security/authgraph/SessionIdSignature.cddl
new file mode 100644
index 0000000..038a0f0
--- /dev/null
+++ b/security/authgraph/aidl/android/hardware/security/authgraph/SessionIdSignature.cddl
@@ -0,0 +1,33 @@
+;
+; Copyright (C) 2023 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.
+;
+SessionIdSignature = [ ; COSE_Sign1 (untagged) [RFC9052 s4.2]
+    protected: bstr .cbor SessionIdSignatureProtected,
+    unprotected: {},
+    payload: nil,       ; session ID payload to be transported separately
+    signature: bstr     ; PureEd25519(privateKey, SessionIdSignatureSigStruct) /
+                        ; ECDSA(privateKey, SessionIdSignatureSigStruct)
+]
+
+SessionIdSignatureProtected = {
+    1 : AlgorithmEdDSA / AlgorithmES256,
+}
+
+SessionIdSignatureSigStruct = [ ; Sig_structure for SessionIdSignature [ RFC9052 s4.4]
+    context: "Signature1",
+    protected: bstr SessionIdSignatureProtected,
+    external_aad: bstr .size 0,
+    payload: bstr,       ; session ID payload provided separately
+]
diff --git a/security/authgraph/aidl/android/hardware/security/authgraph/SessionInfo.aidl b/security/authgraph/aidl/android/hardware/security/authgraph/SessionInfo.aidl
new file mode 100644
index 0000000..ef49a1a
--- /dev/null
+++ b/security/authgraph/aidl/android/hardware/security/authgraph/SessionInfo.aidl
@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2023 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.authgraph;
+
+import android.hardware.security.authgraph.Arc;
+import android.hardware.security.authgraph.SessionIdSignature;
+
+/**
+ * Session information returned as part of authenticated key exchange.
+ */
+@VintfStability
+@RustDerive(Clone=true, Eq=true, PartialEq=true)
+parcelable SessionInfo {
+    /**
+     * The arcs that encrypt the two derived symmetric encryption keys (for two-way communication)
+     * from the party's per-boot key.
+     */
+    Arc[2] sharedKeys;
+
+    /**
+     * The value of the session id computed by the two parties during the authenticate key
+     * exchange. Apart from the usage of the session id by the two peers, session id is also useful
+     * to verify (by a third party) that the key exchange was successful.
+     */
+    byte[] sessionId;
+
+    /**
+     * The signature over the session id, created by the party who computed the session id.
+     *
+     * If there is one or more `DiceChainEntry` in the `ExplicitKeyDiceCertChain` of the party's
+     * identity, the signature is verified with the public key in the leaf of the chain of
+     * DiceChainEntries (i.e the public key in the last of the array of DiceChainEntries).
+     * Otherwise, the signature is verified with the `DiceCertChainInitialPayload`.
+     */
+    SessionIdSignature signature;
+}
diff --git a/security/authgraph/aidl/android/hardware/security/authgraph/SessionInitiationInfo.aidl b/security/authgraph/aidl/android/hardware/security/authgraph/SessionInitiationInfo.aidl
new file mode 100644
index 0000000..c630d91
--- /dev/null
+++ b/security/authgraph/aidl/android/hardware/security/authgraph/SessionInitiationInfo.aidl
@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2023 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.authgraph;
+
+import android.hardware.security.authgraph.Arc;
+import android.hardware.security.authgraph.Identity;
+import android.hardware.security.authgraph.Key;
+
+/**
+ * Session initiation information returned as part of authenticated key exchange.
+ */
+@VintfStability
+@RustDerive(Clone=true, Eq=true, PartialEq=true)
+parcelable SessionInitiationInfo {
+    /**
+     * An ephemeral EC key created for the ECDH process.
+     */
+    Key key;
+
+    /**
+     * The identity of the party who created the Diffie-Hellman key exchange key.
+     */
+    Identity identity;
+
+    /**
+     * Nonce value specific to this session. The nonce serves three purposes:
+     * 1. freshness of key exchange
+     * 2. creating a session id (a publicly known value related to the exchanged keys)
+     * 3. usage as salt into the HKDF-EXTRACT function during key derivation from the shared DH key
+     */
+    byte[] nonce;
+
+    /**
+     * The protocol version (i.e. AIDL version) - This is used to prevent version downgrade attacks
+     * as follows:
+     * 1. In `create`, the source advertises the latest protocol version supported by the source,
+     *    which is given as input to the `init` call on the sink in the input parameter:
+     *    `peerVersion`.
+     * 2. In `init`, the sink includes the `peerVersion` in the inputs to the derivation of the
+     *    shared keys. Then the sink returns the latest protocol version supported by the sink,
+     *    which is given as input to the `finish` call on the source in the input parameter:
+     *    `peerVersion`.
+     * 3. In `finish`, the source first checks whether the sink's version is equal or less than the
+     *    source's version and includes in the source's version in the inputs to the derivation of
+     *    the shared keys.
+     * Analysis: if an attacker-in-the-middle wanted the two parties to use an older (vulnerable)
+     * version of the protocol, they can invoke `init` with a version that is lower than the version
+     * advertised by the source in `create`. However, since both parties include the source's
+     * version in the inputs to the derivation of the shared keys, the two parties won't end up with
+     * the same shared keys in the presence of such an attack. This is detected when checking the
+     * signature on the session id in `finish`, at which point the protocol aborts. Therefore,
+     * an attacker cannot successfully launch a version downgrade attack on this protocol.
+     */
+    int version;
+}
diff --git a/security/authgraph/aidl/android/hardware/security/authgraph/SignedPubKey.aidl b/security/authgraph/aidl/android/hardware/security/authgraph/SignedPubKey.aidl
new file mode 100644
index 0000000..72ee219
--- /dev/null
+++ b/security/authgraph/aidl/android/hardware/security/authgraph/SignedPubKey.aidl
@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2023 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.authgraph;
+
+/**
+ * One of the two enum variants of the enum type: `PubKey`. This represents the public key signed
+ * with the long term signing key of the party.
+ */
+@VintfStability
+@RustDerive(Clone=true, Eq=true, PartialEq=true)
+parcelable SignedPubKey {
+    /* Data is CBOR-encoded according to the `SignedPubKey` CDDL definition in SignedPubKey.cddl */
+    byte[] signedPubKey;
+}
diff --git a/security/authgraph/aidl/android/hardware/security/authgraph/SignedPubKey.cddl b/security/authgraph/aidl/android/hardware/security/authgraph/SignedPubKey.cddl
new file mode 100644
index 0000000..f23a492
--- /dev/null
+++ b/security/authgraph/aidl/android/hardware/security/authgraph/SignedPubKey.cddl
@@ -0,0 +1,41 @@
+;
+; Copyright (C) 2023 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.
+;
+SignedPubKey = [ ; COSE_Sign1 (untagged) [RFC9052 s4.2]
+    protected: bstr .cbor SignedPubKeyProtected,
+    unprotected: {},
+    payload: bstr .cbor PlainPubKey,
+    signature: bstr     ; PureEd25519(privateKey, SignedPubKeySigStruct) /
+                        ; ECDSA(privateKey, SignedPubKeySigStruct)
+]
+
+SignedPubKeyProtected = {
+           1 : AlgorithmEdDSA / AlgorithmES256,
+    ? -70011 : Identity,        ; the party who performs the signing operation adds its own
+                                ; identity to the protected headers.
+}
+
+SignedPubKeySigStruct = [ ; Sig_structure for SignedPubKey [ RFC9052 s4.4]
+    context: "Signature1",
+    protected: bstr SignedPubKeyProtected,
+    external_aad: bstr .size 0,
+    payload: bstr .cbor PlainPubKey,
+]
+
+AlgorithmES256 = -7              ; [RFC9053 s2.1]
+AlgorithmEdDSA = -8              ; [RFC9053 s2.2]
+
+; INCLUDE PlainPubKey.cddl for: PlainPubKey
+; INCLUDE Identity.cddl for: Identity
\ No newline at end of file