diff --git a/core/java/android/util/PackageUtils.java b/core/java/android/util/PackageUtils.java
index 6f8c5db..ea7efc7 100644
--- a/core/java/android/util/PackageUtils.java
+++ b/core/java/android/util/PackageUtils.java
@@ -184,24 +184,15 @@
     }
 
     /**
-     * @see #computeSha256DigestForLargeFile(String, byte[], String)
-     */
-    public static @Nullable String computeSha256DigestForLargeFile(@NonNull String filePath,
-            @NonNull byte[] fileBuffer) {
-        return computeSha256DigestForLargeFile(filePath, fileBuffer, null);
-    }
-
-    /**
-     * Computes the SHA256 digest of large files. This is typically useful for large APEXs.
+     * Computes the SHA256 digest of a large file.
      * @param filePath The path to which the file's content is to be hashed.
      * @param fileBuffer A buffer to read file's content into memory. It is strongly recommended to
      *                   make use of the {@link #createLargeFileBuffer()} method to create this
      *                   buffer.
-     * @param separator Separator between each pair of characters, such as colon, or null to omit.
-     * @return The SHA256 digest or null if an error occurs.
+     * @return The byte array of SHA256 digest or null if an error occurs.
      */
-    public static @Nullable String computeSha256DigestForLargeFile(@NonNull String filePath,
-            @NonNull byte[] fileBuffer, @Nullable String separator) {
+    public static @Nullable byte[] computeSha256DigestForLargeFileAsBytes(@NonNull String filePath,
+            @NonNull byte[] fileBuffer) {
         MessageDigest messageDigest;
         try {
             messageDigest = MessageDigest.getInstance("SHA256");
@@ -221,8 +212,30 @@
             return null;
         }
 
-        byte[] resultBytes = messageDigest.digest();
+        return messageDigest.digest();
+    }
 
+    /**
+     * @see #computeSha256DigestForLargeFile(String, byte[], String)
+     */
+    public static @Nullable String computeSha256DigestForLargeFile(@NonNull String filePath,
+            @NonNull byte[] fileBuffer) {
+        return computeSha256DigestForLargeFile(filePath, fileBuffer, null);
+    }
+
+    /**
+     * Computes the SHA256 digest of a large file.
+     * @param filePath The path to which the file's content is to be hashed.
+     * @param fileBuffer A buffer to read file's content into memory. It is strongly recommended to
+     *                   make use of the {@link #createLargeFileBuffer()} method to create this
+     *                   buffer.
+     * @param separator Separator between each pair of characters, such as colon, or null to omit.
+     * @see #computeSha256DigestForLargeFile(String, byte[])
+     * @return The encoded string of SHA256 digest or null if an error occurs.
+     */
+    public static @Nullable String computeSha256DigestForLargeFile(@NonNull String filePath,
+            @NonNull byte[] fileBuffer, @Nullable String separator) {
+        byte[] resultBytes = computeSha256DigestForLargeFileAsBytes(filePath, fileBuffer);
         if (separator == null) {
             return HexEncoding.encodeToString(resultBytes, false);
         }
diff --git a/services/core/java/com/android/server/BinaryTransparencyService.java b/services/core/java/com/android/server/BinaryTransparencyService.java
index eafd3e0..f49dfeb 100644
--- a/services/core/java/com/android/server/BinaryTransparencyService.java
+++ b/services/core/java/com/android/server/BinaryTransparencyService.java
@@ -263,26 +263,26 @@
             Map<Integer, byte[]> contentDigests = computeApkContentDigest(apkPath);
             if (contentDigests == null) {
                 Slog.d(TAG, "Failed to compute content digest for " + apkPath);
-                return new Checksum(0, new byte[] { -1 });
-            }
-
-            // in this iteration, we'll be supporting only 2 types of digests:
-            // CHUNKED_SHA256 and CHUNKED_SHA512.
-            // And only one of them will be available per package.
-            if (contentDigests.containsKey(ApkSigningBlockUtils.CONTENT_DIGEST_CHUNKED_SHA256)) {
-                return new Checksum(
-                        Checksum.TYPE_PARTIAL_MERKLE_ROOT_1M_SHA256,
-                        contentDigests.get(ApkSigningBlockUtils.CONTENT_DIGEST_CHUNKED_SHA256));
-            } else if (contentDigests.containsKey(
-                    ApkSigningBlockUtils.CONTENT_DIGEST_CHUNKED_SHA512)) {
-                return new Checksum(
-                        Checksum.TYPE_PARTIAL_MERKLE_ROOT_1M_SHA512,
-                        contentDigests.get(ApkSigningBlockUtils.CONTENT_DIGEST_CHUNKED_SHA512));
             } else {
-                // TODO(b/259423111): considering putting the raw values for the algorithm & digest
-                //  into the bundle to track potential other digest algorithms that may be in use
-                return new Checksum(0, new byte[] { -1 });
+                // in this iteration, we'll be supporting only 2 types of digests:
+                // CHUNKED_SHA256 and CHUNKED_SHA512.
+                // And only one of them will be available per package.
+                if (contentDigests.containsKey(
+                            ApkSigningBlockUtils.CONTENT_DIGEST_CHUNKED_SHA256)) {
+                    return new Checksum(
+                            Checksum.TYPE_PARTIAL_MERKLE_ROOT_1M_SHA256,
+                            contentDigests.get(ApkSigningBlockUtils.CONTENT_DIGEST_CHUNKED_SHA256));
+                } else if (contentDigests.containsKey(
+                        ApkSigningBlockUtils.CONTENT_DIGEST_CHUNKED_SHA512)) {
+                    return new Checksum(
+                            Checksum.TYPE_PARTIAL_MERKLE_ROOT_1M_SHA512,
+                            contentDigests.get(ApkSigningBlockUtils.CONTENT_DIGEST_CHUNKED_SHA512));
+                }
             }
+            // When something went wrong, fall back to simple sha256.
+            byte[] digest = PackageUtils.computeSha256DigestForLargeFileAsBytes(apkPath,
+                    PackageUtils.createLargeFileBuffer());
+            return new Checksum(Checksum.TYPE_WHOLE_SHA256, digest);
         }