diff --git a/identity/aidl/android/hardware/identity/IIdentityCredential.aidl b/identity/aidl/android/hardware/identity/IIdentityCredential.aidl
index 10ce4c2..cc14271 100644
--- a/identity/aidl/android/hardware/identity/IIdentityCredential.aidl
+++ b/identity/aidl/android/hardware/identity/IIdentityCredential.aidl
@@ -176,6 +176,10 @@
      * @param itemsRequest
      *   If non-empty, contains request data that is signed by the reader. See above.
      *
+     * @param signingKeyBlob is either empty or a signingKeyBlob (see generateSigningKeyPair(),
+     *    below) containing the signing key to use to sign the data retrieved. If this
+     *    is not in the right format the call fails with STATUS_INVALID_DATA.
+     *
      * @param sessionTranscript
      *   Either empty or the CBOR of the SessionTranscript. See above.
      *
@@ -195,8 +199,7 @@
      *   and remove the corresponding requests from the counts.
      */
     void startRetrieval(in SecureAccessControlProfile[] accessControlProfiles,
-        in HardwareAuthToken authToken,
-        in byte[] itemsRequest,
+        in HardwareAuthToken authToken, in byte[] itemsRequest, in byte[] signingKeyBlob,
         in byte[] sessionTranscript, in byte[] readerSignature, in int[] requestCounts);
 
     /**
@@ -254,10 +257,6 @@
      * If signingKeyBlob or the sessionTranscript parameter passed to startRetrieval() is
      * empty then the returned MAC will be empty.
      *
-     * @param signingKeyBlob is either empty or a signingKeyBlob (see generateSigningKeyPair(),
-     *    below) containing the signing key to use to sign the data retrieved. If this
-     *    is not in the right format the call fails with STATUS_INVALID_DATA.
-     *
      * @param out mac is empty if signingKeyBlob or the sessionTranscript passed to
      *    startRetrieval() is empty. Otherwise it is a COSE_Mac0 with empty payload
      *    and the detached content is set to DeviceAuthentication as defined below.
@@ -304,7 +303,7 @@
      *
      * @param out deviceNameSpaces the bytes of DeviceNameSpaces.
      */
-    void finishRetrieval(in byte[] signingKeyBlob, out byte[] mac, out byte[] deviceNameSpaces);
+    void finishRetrieval(out byte[] mac, out byte[] deviceNameSpaces);
 
     /**
      * Generate a key pair to be used for signing session data and retrieved data items.
diff --git a/identity/aidl/default/IdentityCredential.cpp b/identity/aidl/default/IdentityCredential.cpp
index d5b3a0f..341fae6 100644
--- a/identity/aidl/default/IdentityCredential.cpp
+++ b/identity/aidl/default/IdentityCredential.cpp
@@ -256,8 +256,8 @@
 ndk::ScopedAStatus IdentityCredential::startRetrieval(
         const vector<SecureAccessControlProfile>& accessControlProfiles,
         const HardwareAuthToken& authToken, const vector<int8_t>& itemsRequestS,
-        const vector<int8_t>& sessionTranscriptS, const vector<int8_t>& readerSignatureS,
-        const vector<int32_t>& requestCounts) {
+        const vector<int8_t>& signingKeyBlobS, const vector<int8_t>& sessionTranscriptS,
+        const vector<int8_t>& readerSignatureS, const vector<int32_t>& requestCounts) {
     auto sessionTranscript = byteStringToUnsigned(sessionTranscriptS);
     auto itemsRequest = byteStringToUnsigned(itemsRequestS);
     auto readerSignature = byteStringToUnsigned(readerSignatureS);
@@ -498,6 +498,7 @@
     currentNameSpace_ = "";
 
     itemsRequest_ = itemsRequest;
+    signingKeyBlob_ = byteStringToUnsigned(signingKeyBlobS);
 
     numStartRetrievalCalls_ += 1;
     return ndk::ScopedAStatus::ok();
@@ -650,11 +651,8 @@
     return ndk::ScopedAStatus::ok();
 }
 
-ndk::ScopedAStatus IdentityCredential::finishRetrieval(const vector<int8_t>& signingKeyBlobS,
-                                                       vector<int8_t>* outMac,
+ndk::ScopedAStatus IdentityCredential::finishRetrieval(vector<int8_t>* outMac,
                                                        vector<int8_t>* outDeviceNameSpaces) {
-    auto signingKeyBlob = byteStringToUnsigned(signingKeyBlobS);
-
     if (currentNameSpaceDeviceNameSpacesMap_.size() > 0) {
         deviceNameSpacesMap_.add(currentNameSpace_,
                                  std::move(currentNameSpaceDeviceNameSpacesMap_));
@@ -664,7 +662,8 @@
     // If there's no signing key or no sessionTranscript or no reader ephemeral
     // public key, we return the empty MAC.
     optional<vector<uint8_t>> mac;
-    if (signingKeyBlob.size() > 0 && sessionTranscript_.size() > 0 && readerPublicKey_.size() > 0) {
+    if (signingKeyBlob_.size() > 0 && sessionTranscript_.size() > 0 &&
+        readerPublicKey_.size() > 0) {
         cppbor::Array array;
         array.add("DeviceAuthentication");
         array.add(sessionTranscriptItem_->clone());
@@ -674,7 +673,7 @@
 
         vector<uint8_t> docTypeAsBlob(docType_.begin(), docType_.end());
         optional<vector<uint8_t>> signingKey =
-                support::decryptAes128Gcm(storageKey_, signingKeyBlob, docTypeAsBlob);
+                support::decryptAes128Gcm(storageKey_, signingKeyBlob_, docTypeAsBlob);
         if (!signingKey) {
             return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
                     IIdentityCredentialStore::STATUS_INVALID_DATA,
diff --git a/identity/aidl/default/IdentityCredential.h b/identity/aidl/default/IdentityCredential.h
index 49ed0d4..fc29254 100644
--- a/identity/aidl/default/IdentityCredential.h
+++ b/identity/aidl/default/IdentityCredential.h
@@ -54,14 +54,14 @@
     ndk::ScopedAStatus startRetrieval(
             const vector<SecureAccessControlProfile>& accessControlProfiles,
             const HardwareAuthToken& authToken, const vector<int8_t>& itemsRequest,
-            const vector<int8_t>& sessionTranscript, const vector<int8_t>& readerSignature,
-            const vector<int32_t>& requestCounts) override;
+            const vector<int8_t>& signingKeyBlob, const vector<int8_t>& sessionTranscript,
+            const vector<int8_t>& readerSignature, const vector<int32_t>& requestCounts) override;
     ndk::ScopedAStatus startRetrieveEntryValue(
             const string& nameSpace, const string& name, int32_t entrySize,
             const vector<int32_t>& accessControlProfileIds) override;
     ndk::ScopedAStatus retrieveEntryValue(const vector<int8_t>& encryptedContent,
                                           vector<int8_t>* outContent) override;
-    ndk::ScopedAStatus finishRetrieval(const vector<int8_t>& signingKeyBlob, vector<int8_t>* outMac,
+    ndk::ScopedAStatus finishRetrieval(vector<int8_t>* outMac,
                                        vector<int8_t>* outDeviceNameSpaces) override;
     ndk::ScopedAStatus generateSigningKeyPair(vector<int8_t>* outSigningKeyBlob,
                                               Certificate* outSigningKeyCertificate) override;
@@ -88,6 +88,7 @@
 
     // Set at startRetrieval() time.
     map<int32_t, int> profileIdToAccessCheckResult_;
+    vector<uint8_t> signingKeyBlob_;
     vector<uint8_t> sessionTranscript_;
     std::unique_ptr<cppbor::Item> sessionTranscriptItem_;
     vector<uint8_t> itemsRequest_;
diff --git a/identity/aidl/vts/VtsHalIdentityTargetTest.cpp b/identity/aidl/vts/VtsHalIdentityTargetTest.cpp
index 5abe5a2..ea37fdc 100644
--- a/identity/aidl/vts/VtsHalIdentityTargetTest.cpp
+++ b/identity/aidl/vts/VtsHalIdentityTargetTest.cpp
@@ -352,10 +352,15 @@
                                    readerCertificate.value());
     ASSERT_TRUE(readerSignature);
 
+    // Generate the key that will be used to sign AuthenticatedData.
+    vector<uint8_t> signingKeyBlob;
+    Certificate signingKeyCertificate;
+    ASSERT_TRUE(credential->generateSigningKeyPair(&signingKeyBlob, &signingKeyCertificate).isOk());
+
     ASSERT_TRUE(credential
                         ->startRetrieval(returnedSecureProfiles, authToken, itemsRequestBytes,
-                                         sessionTranscriptBytes, readerSignature.value(),
-                                         testEntriesEntryCounts)
+                                         signingKeyBlob, sessionTranscriptBytes,
+                                         readerSignature.value(), testEntriesEntryCounts)
                         .isOk());
 
     for (const auto& entry : testEntries) {
@@ -377,14 +382,9 @@
         EXPECT_EQ(content, entry.valueCbor);
     }
 
-    // Generate the key that will be used to sign AuthenticatedData.
-    vector<uint8_t> signingKeyBlob;
-    Certificate signingKeyCertificate;
-    ASSERT_TRUE(credential->generateSigningKeyPair(&signingKeyBlob, &signingKeyCertificate).isOk());
-
     vector<uint8_t> mac;
     vector<uint8_t> deviceNameSpacesBytes;
-    ASSERT_TRUE(credential->finishRetrieval(signingKeyBlob, &mac, &deviceNameSpacesBytes).isOk());
+    ASSERT_TRUE(credential->finishRetrieval(&mac, &deviceNameSpacesBytes).isOk());
     cborPretty = support::cborPrettyPrint(deviceNameSpacesBytes, 32, {});
     ASSERT_EQ(
             "{\n"