diff --git a/keystore/KeyAttestationApplicationId.cpp b/keystore/KeyAttestationApplicationId.cpp
index c62571f..1838b07 100644
--- a/keystore/KeyAttestationApplicationId.cpp
+++ b/keystore/KeyAttestationApplicationId.cpp
@@ -26,8 +26,8 @@
 KeyAttestationApplicationId::KeyAttestationApplicationId() = default;
 
 KeyAttestationApplicationId::KeyAttestationApplicationId(
-        std::unique_ptr<KeyAttestationPackageInfo> package) :
-    packageInfos_(new std::vector<std::unique_ptr<KeyAttestationPackageInfo>>()) {
+    std::optional<KeyAttestationPackageInfo> package)
+    : packageInfos_(new std::vector<std::optional<KeyAttestationPackageInfo>>()) {
     packageInfos_->push_back(std::move(package));
 }
 
@@ -39,10 +39,13 @@
 }
 
 status_t KeyAttestationApplicationId::readFromParcel(const Parcel* parcel) {
-    std::unique_ptr<std::vector<std::unique_ptr<KeyAttestationPackageInfo>>> temp_vector;
+    std::optional<std::vector<std::optional<KeyAttestationPackageInfo>>> temp_vector;
     auto rc = parcel->readParcelableVector(&temp_vector);
     if (rc != NO_ERROR) return rc;
-    packageInfos_.reset(temp_vector.release());
+    packageInfos_.reset();
+    if (temp_vector) {
+        packageInfos_ = std::make_shared<PackageInfoVector>(std::move(*temp_vector));
+    }
     return NO_ERROR;
 }
 
diff --git a/keystore/KeyAttestationPackageInfo.cpp b/keystore/KeyAttestationPackageInfo.cpp
index 75fbb7a..8e9a36a 100644
--- a/keystore/KeyAttestationPackageInfo.cpp
+++ b/keystore/KeyAttestationPackageInfo.cpp
@@ -28,7 +28,7 @@
 KeyAttestationPackageInfo::KeyAttestationPackageInfo(const String16& packageName,
                                                      int64_t versionCode,
                                                      SharedSignaturesVector signatures)
-    : packageName_(new String16(packageName)), versionCode_(versionCode), signatures_(signatures) {}
+    : packageName_(packageName), versionCode_(versionCode), signatures_(signatures) {}
 
 status_t KeyAttestationPackageInfo::writeToParcel(Parcel* parcel) const {
     auto rc = parcel->writeString16(packageName_);
@@ -44,10 +44,13 @@
     rc = parcel->readInt64(&versionCode_);
     if (rc != NO_ERROR) return rc;
 
-    std::unique_ptr<SignaturesVector> temp_vector;
+    std::optional<SignaturesVector> temp_vector;
     rc = parcel->readParcelableVector(&temp_vector);
     if (rc != NO_ERROR) return rc;
-    signatures_.reset(temp_vector.release());
+    signatures_.reset();
+    if (temp_vector) {
+        signatures_ = std::make_shared<SignaturesVector>(std::move(*temp_vector));
+    }
     return NO_ERROR;
 }
 
diff --git a/keystore/include/keystore/KeyAttestationApplicationId.h b/keystore/include/keystore/KeyAttestationApplicationId.h
index 861c2e1..0bf1aad 100644
--- a/keystore/include/keystore/KeyAttestationApplicationId.h
+++ b/keystore/include/keystore/KeyAttestationApplicationId.h
@@ -16,6 +16,7 @@
 #define KEYSTORE_INCLUDE_KEYSTORE_KEYATTESTATIONAPPLICATIONID_H_
 
 #include <memory>
+#include <optional>
 #include <vector>
 
 #include <binder/Parcelable.h>
@@ -30,10 +31,10 @@
   public:
     typedef SharedNullableIterator<const KeyAttestationPackageInfo, std::vector>
         ConstKeyAttestationPackageInfoIterator;
-    typedef std::vector<std::unique_ptr<KeyAttestationPackageInfo>> PackageInfoVector;
+    typedef std::vector<std::optional<KeyAttestationPackageInfo>> PackageInfoVector;
     KeyAttestationApplicationId();
     // Following c'tors are for initializing instances containing test data.
-    explicit KeyAttestationApplicationId(std::unique_ptr<KeyAttestationPackageInfo> package);
+    explicit KeyAttestationApplicationId(std::optional<KeyAttestationPackageInfo> package);
     explicit KeyAttestationApplicationId(PackageInfoVector packages);
 
     status_t writeToParcel(Parcel*) const override;
@@ -47,7 +48,7 @@
     }
 
   private:
-    std::shared_ptr<std::vector<std::unique_ptr<KeyAttestationPackageInfo>>> packageInfos_;
+    std::shared_ptr<PackageInfoVector> packageInfos_;
 };
 
 }  // namespace keymaster
diff --git a/keystore/include/keystore/KeyAttestationPackageInfo.h b/keystore/include/keystore/KeyAttestationPackageInfo.h
index 92d4863..fa638f9 100644
--- a/keystore/include/keystore/KeyAttestationPackageInfo.h
+++ b/keystore/include/keystore/KeyAttestationPackageInfo.h
@@ -18,6 +18,7 @@
 #include <stdint.h>
 
 #include <memory>
+#include <optional>
 #include <vector>
 
 #include <binder/Parcelable.h>
@@ -33,8 +34,7 @@
   public:
     typedef SharedNullableIterator<const content::pm::Signature, std::vector>
         ConstSignatureIterator;
-    typedef std::vector<std::unique_ptr<content::pm::Signature>>
-        SignaturesVector;
+    typedef std::vector<std::optional<content::pm::Signature>> SignaturesVector;
     typedef std::shared_ptr<SignaturesVector> SharedSignaturesVector;
 
     KeyAttestationPackageInfo(const String16& packageName, int64_t versionCode,
@@ -44,14 +44,14 @@
     status_t writeToParcel(Parcel*) const override;
     status_t readFromParcel(const Parcel* parcel) override;
 
-    const std::unique_ptr<String16>& package_name() const { return packageName_; }
+    const std::optional<String16>& package_name() const { return packageName_; }
     int64_t version_code() const { return versionCode_; }
 
     ConstSignatureIterator sigs_begin() const { return ConstSignatureIterator(signatures_); }
     ConstSignatureIterator sigs_end() const { return ConstSignatureIterator(); }
 
   private:
-    std::unique_ptr<String16> packageName_;
+    std::optional<String16> packageName_;
     int64_t versionCode_;
     SharedSignaturesVector signatures_;
 };
diff --git a/keystore/include/keystore/KeystoreResponse.h b/keystore/include/keystore/KeystoreResponse.h
index 20f7274..4a7ef0d 100644
--- a/keystore/include/keystore/KeystoreResponse.h
+++ b/keystore/include/keystore/KeystoreResponse.h
@@ -31,29 +31,24 @@
   public:
     KeystoreResponse() = default;
     explicit KeystoreResponse(const int response_code, const String16& error_msg)
-        : response_code_(response_code), error_msg_(std::make_unique<String16>(error_msg)) {}
+        : response_code_(response_code), error_msg_(error_msg) {}
     explicit KeystoreResponse(const int response_code)
         : response_code_(response_code), error_msg_() {}
     // NOLINTNEXTLINE(google-explicit-constructor)
     KeystoreResponse(const ::keystore::KeyStoreServiceReturnCode& rc)
         : response_code_(rc.getErrorCode()), error_msg_() {}
-    KeystoreResponse(const KeystoreResponse& other)
-        : response_code_(other.response_code_), error_msg_() {
-        if (other.error_msg_) {
-            error_msg_ = std::make_unique<String16>(*other.error_msg_);
-        }
-    }
+    KeystoreResponse(const KeystoreResponse& other) = default;
     KeystoreResponse(KeystoreResponse&& other) = default;
 
     status_t readFromParcel(const Parcel* in) override;
     status_t writeToParcel(Parcel* out) const override;
 
     int response_code() const { return response_code_; }
-    const String16* error_msg() const { return error_msg_.get(); }
+    const std::optional<String16>& error_msg() const { return error_msg_; }
 
   private:
     int response_code_;
-    std::unique_ptr<String16> error_msg_;
+    std::optional<String16> error_msg_;
 };
 
 }  // namespace keystore
diff --git a/keystore/include/keystore/utils.h b/keystore/include/keystore/utils.h
index 544dd21..2143d3a 100644
--- a/keystore/include/keystore/utils.h
+++ b/keystore/include/keystore/utils.h
@@ -5,6 +5,7 @@
 
 #include <iterator>
 #include <memory>
+#include <optional>
 #include <vector>
 
 namespace android {
@@ -12,7 +13,7 @@
 
 /*
  * This iterator abstracts from a collection of the form
- * std::shared_ptr<COLLECTION_TYPE<std::unique_ptr<T>>>
+ * std::shared_ptr<COLLECTION_TYPE<std::optional<T>>>
  * such that it is defined both for nulled outer pointer and
  * nulled entries. If shared_ptr(nullptr) is passed in, the iterator behaves
  * like the end iterator yielding an empty collection. Nulled
@@ -25,7 +26,7 @@
 template <typename T, template <typename...> class Coll = std::vector>
 class SharedNullableIterator {
   public:
-    typedef Coll<std::unique_ptr<typename std::remove_const<T>::type>> CollectionType;
+    typedef Coll<std::optional<typename std::remove_const<T>::type>> CollectionType;
     typedef std::shared_ptr<CollectionType> CollectionPtr;
 
     SharedNullableIterator() {}
diff --git a/keystore/keystore_attestation_id.cpp b/keystore/keystore_attestation_id.cpp
index 3d9e87e..ccd3808 100644
--- a/keystore/keystore_attestation_id.cpp
+++ b/keystore/keystore_attestation_id.cpp
@@ -271,7 +271,7 @@
 
     if (uid == AID_SYSTEM) {
         /* Use a fixed ID for system callers */
-        auto pinfo = std::make_unique<KeyAttestationPackageInfo>(
+        auto pinfo = std::make_optional<KeyAttestationPackageInfo>(
             String16(kAttestationSystemPackageName), 1 /* version code */,
             std::make_shared<KeyAttestationPackageInfo::SignaturesVector>());
         key_attestation_id = KeyAttestationApplicationId(std::move(pinfo));
@@ -284,7 +284,7 @@
         if (!status.isOk()) {
             ALOGW("package manager request for key attestation ID failed with: %s %d",
                   status.exceptionMessage().string(), status.exceptionCode());
-            auto pinfo = std::make_unique<KeyAttestationPackageInfo>(
+            auto pinfo = std::make_optional<KeyAttestationPackageInfo>(
                 String16(kUnknownPackageName), 1 /* version code */,
                 std::make_shared<KeyAttestationPackageInfo::SignaturesVector>());
             key_attestation_id = KeyAttestationApplicationId(std::move(pinfo));
diff --git a/keystore/tests/aaid_truncation_test.cpp b/keystore/tests/aaid_truncation_test.cpp
index 45c54df..fa4d769 100644
--- a/keystore/tests/aaid_truncation_test.cpp
+++ b/keystore/tests/aaid_truncation_test.cpp
@@ -75,15 +75,15 @@
 using ::android::content::pm::Signature;
 using ::android::security::build_attestation_application_id;
 
-std::unique_ptr<KeyAttestationPackageInfo>
+std::optional<KeyAttestationPackageInfo>
 make_package_info_with_signatures(const char* package_name,
                                   KeyAttestationPackageInfo::SignaturesVector signatures) {
-    return std::make_unique<KeyAttestationPackageInfo>(
+    return std::make_optional<KeyAttestationPackageInfo>(
         String16(package_name), 1 /* version code */,
         std::make_shared<KeyAttestationPackageInfo::SignaturesVector>(std::move(signatures)));
 }
 
-std::unique_ptr<KeyAttestationPackageInfo> make_package_info(const char* package_name) {
+std::optional<KeyAttestationPackageInfo> make_package_info(const char* package_name) {
     return make_package_info_with_signatures(package_name,
                                              KeyAttestationPackageInfo::SignaturesVector());
 }
@@ -111,7 +111,7 @@
     KeyAttestationPackageInfo::SignaturesVector signatures;
     // Add 35 signatures which will surely exceed the 1K limit.
     for (size_t i = 0; i < kTooManySignatures; ++i) {
-        signatures.push_back(std::make_unique<Signature>(dummy_sig_data));
+        signatures.push_back(std::make_optional<Signature>(dummy_sig_data));
     }
 
     KeyAttestationApplicationId app_id(
@@ -131,7 +131,7 @@
         KeyAttestationPackageInfo::SignaturesVector signatures;
         // Add a few signatures for each package
         for (int j = 0; j < 3; ++j) {
-            signatures.push_back(std::make_unique<Signature>(dummy_sig_data));
+            signatures.push_back(std::make_optional<Signature>(dummy_sig_data));
         }
         packages.push_back(
             make_package_info_with_signatures(kReasonablePackageName, std::move(signatures)));