diff --git a/cas/1.0/default/DescramblerImpl.cpp b/cas/1.0/default/DescramblerImpl.cpp
new file mode 100644
index 0000000..3d90809
--- /dev/null
+++ b/cas/1.0/default/DescramblerImpl.cpp
@@ -0,0 +1,127 @@
+/*
+ * Copyright (C) 2017 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.
+ */
+
+//#define LOG_NDEBUG 0
+#define LOG_TAG "android.hardware.cas@1.0-DescramblerImpl"
+
+#include <hidlmemory/mapping.h>
+#include <media/hardware/CryptoAPI.h>
+#include <media/cas/DescramblerAPI.h>
+#include <utils/Log.h>
+
+#include "DescramblerImpl.h"
+#include "SharedLibrary.h"
+#include "TypeConvert.h"
+
+namespace android {
+using hidl::memory::V1_0::IMemory;
+
+namespace hardware {
+namespace cas {
+namespace V1_0 {
+namespace implementation {
+
+#define CHECK_SUBSAMPLE_DEF(type) \
+static_assert(sizeof(SubSample) == sizeof(type::SubSample), \
+        "SubSample: size doesn't match"); \
+static_assert(offsetof(SubSample, numBytesOfClearData) \
+        == offsetof(type::SubSample, mNumBytesOfClearData), \
+        "SubSample: numBytesOfClearData offset doesn't match"); \
+static_assert(offsetof(SubSample, numBytesOfEncryptedData) \
+        == offsetof(type::SubSample, mNumBytesOfEncryptedData), \
+        "SubSample: numBytesOfEncryptedData offset doesn't match")
+
+CHECK_SUBSAMPLE_DEF(DescramblerPlugin);
+CHECK_SUBSAMPLE_DEF(CryptoPlugin);
+
+DescramblerImpl::DescramblerImpl(
+        const sp<SharedLibrary>& library, DescramblerPlugin *plugin) :
+        mLibrary(library), mPlugin(plugin) {
+    ALOGV("CTOR: mPlugin=%p", mPlugin);
+}
+
+DescramblerImpl::~DescramblerImpl() {
+    ALOGV("DTOR: mPlugin=%p", mPlugin);
+    release();
+}
+
+Return<Status> DescramblerImpl::setMediaCasSession(const HidlCasSessionId& sessionId) {
+    ALOGV("%s: sessionId=%s", __FUNCTION__,
+            sessionIdToString(sessionId).string());
+
+    return toStatus(mPlugin->setMediaCasSession(sessionId));
+}
+
+Return<bool> DescramblerImpl::requiresSecureDecoderComponent(
+        const hidl_string& mime) {
+    return mPlugin->requiresSecureDecoderComponent(String8(mime.c_str()));
+}
+
+Return<void> DescramblerImpl::descramble(
+        ScramblingControl scramblingControl,
+        const hidl_vec<SubSample>& subSamples,
+        const SharedBuffer& srcBuffer,
+        uint64_t srcOffset,
+        const DestinationBuffer& dstBuffer,
+        uint64_t dstOffset,
+        descramble_cb _hidl_cb) {
+    ALOGV("%s", __FUNCTION__);
+
+    sp<IMemory> srcMem = mapMemory(srcBuffer.heapBase);
+    void *srcPtr = (uint8_t *)(void *)srcMem->getPointer() + srcBuffer.offset;
+    void *dstPtr = NULL;
+    if (dstBuffer.type == BufferType::SHARED_MEMORY) {
+        // When using shared memory, src buffer is also used as dst,
+        // we don't map it again here.
+        dstPtr = srcPtr;
+    } else {
+        native_handle_t *handle = const_cast<native_handle_t *>(
+                dstBuffer.secureMemory.getNativeHandle());
+        dstPtr = static_cast<void *>(handle);
+    }
+    // Casting hidl SubSample to DescramblerPlugin::SubSample, but need
+    // to ensure structs are actually idential
+
+    int32_t result = mPlugin->descramble(
+            dstBuffer.type != BufferType::SHARED_MEMORY,
+            (DescramblerPlugin::ScramblingControl)scramblingControl,
+            subSamples.size(),
+            (DescramblerPlugin::SubSample*)subSamples.data(),
+            srcPtr,
+            srcOffset,
+            dstPtr,
+            dstOffset,
+            NULL);
+
+    _hidl_cb(toStatus(result >= 0 ? OK : result), result, NULL);
+    return Void();
+}
+
+Return<Status> DescramblerImpl::release() {
+    ALOGV("%s: mPlugin=%p", __FUNCTION__, mPlugin);
+
+    if (mPlugin != NULL) {
+        delete mPlugin;
+        mPlugin = NULL;
+    }
+    return Status::OK;
+}
+
+} // namespace implementation
+} // namespace V1_0
+} // namespace cas
+} // namespace hardware
+} // namespace android