diff --git a/BUILD b/BUILD
index 9546384..9af40a2 100644
--- a/BUILD
+++ b/BUILD
@@ -16,6 +16,7 @@ pkg_tar(
     files = [
         "//example:binary_release_files",
         "//media_cas_packager_sdk/public:binary_release_files",
+        "//util:binary_release_files",
     ],
     mode = "0644",
 )
diff --git a/media_cas_packager_sdk/public/wv_cas_ecm.cc b/media_cas_packager_sdk/public/wv_cas_ecm.cc
index 630e023..a642ba6 100644
--- a/media_cas_packager_sdk/public/wv_cas_ecm.cc
+++ b/media_cas_packager_sdk/public/wv_cas_ecm.cc
@@ -83,7 +83,8 @@ util::Status WvCasEcm::GenerateEcm(const std::string& even_key,
                                    const std::string& odd_key,
                                    const std::string& odd_content_iv,
                                    const std::string& entitlement_key_id,
-                                   const std::string& entitlement_key, std::string* ecm) {
+                                   const std::string& entitlement_key,
+                                   std::string* ecm) const {
   DCHECK(ecm);
   if (!initialized_) {
     return util::Status(util::error::INTERNAL,
@@ -159,7 +160,7 @@ util::Status WvCasEcm::GenerateSingleKeyEcm(const std::string& even_key,
                                             const std::string& even_content_iv,
                                             const std::string& entitlement_key_id,
                                             const std::string& entitlement_key,
-                                            std::string* ecm) {
+                                            std::string* ecm) const {
   if (!initialized_) {
     DCHECK(ecm);
     return util::Status(util::error::INTERNAL,
diff --git a/media_cas_packager_sdk/public/wv_cas_ecm.h b/media_cas_packager_sdk/public/wv_cas_ecm.h
index 47d5b20..b59f785 100644
--- a/media_cas_packager_sdk/public/wv_cas_ecm.h
+++ b/media_cas_packager_sdk/public/wv_cas_ecm.h
@@ -51,8 +51,8 @@ class WvCasEcm {
   //
   // Note:
   // - 'even'/'odd' key in the ECM will be be encrypted using AEC_CBC
-  util::Status Initialize(int content_iv_size, bool key_rotation_enabled,
-                          int crypto_mode);
+  virtual util::Status Initialize(int content_iv_size,
+                                  bool key_rotation_enabled, int crypto_mode);
 
   // Generate an ECM containing two keys (even and odd). Can be called when
   // |key_rotation_enabled| is initialized to 'true'.
@@ -74,11 +74,13 @@ class WvCasEcm {
   //   and |odd_key| in the ECM
   // - Size of |even_content_iv| and |odd_content_iv| must match
   //   |content_iv_size| set during initialization
-  util::Status GenerateEcm(const std::string& even_key,
-                           const std::string& even_content_iv, const std::string& odd_key,
-                           const std::string& odd_content_iv,
-                           const std::string& entitlement_key_id,
-                           const std::string& entitlement_key, std::string* ecm);
+  virtual util::Status GenerateEcm(const std::string& even_key,
+                                   const std::string& even_content_iv,
+                                   const std::string& odd_key,
+                                   const std::string& odd_content_iv,
+                                   const std::string& entitlement_key_id,
+                                   const std::string& entitlement_key,
+                                   std::string* ecm) const;
 
   // Generate an ECM containing only a singe even key. Can be called when
   // |key_rotation_enabled| is initialized to 'false'.
@@ -96,10 +98,11 @@ class WvCasEcm {
   // Note:
   // - Size of |even_content_iv| and |odd_content_iv| must match
   //   |content_iv_size| set during initialization
-  util::Status GenerateSingleKeyEcm(const std::string& even_key,
-                                    const std::string& even_content_iv,
-                                    const std::string& entitlement_key_id,
-                                    const std::string& entitlement_key, std::string* ecm);
+  virtual util::Status GenerateSingleKeyEcm(const std::string& even_key,
+                                            const std::string& even_content_iv,
+                                            const std::string& entitlement_key_id,
+                                            const std::string& entitlement_key,
+                                            std::string* ecm) const;
 
  private:
   bool initialized_ = false;