diff --git a/core/java/android/companion/BluetoothLeDeviceFilter.java b/core/java/android/companion/BluetoothLeDeviceFilter.java
index 1de931eeb6758..268640edad88c 100644
--- a/core/java/android/companion/BluetoothLeDeviceFilter.java
+++ b/core/java/android/companion/BluetoothLeDeviceFilter.java
@@ -39,6 +39,8 @@ import com.android.internal.util.BitUtils;
 import com.android.internal.util.ObjectUtils;
 import com.android.internal.util.Preconditions;
 
+import libcore.util.HexEncoding;
+
 import java.nio.ByteOrder;
 import java.util.Arrays;
 import java.util.Objects;
@@ -152,7 +154,7 @@ public final class BluetoothLeDeviceFilter implements DeviceFilter<ScanResult> {
             int initial = mRenameBytesReverseOrder ? endInclusive : startInclusive;
             int step = mRenameBytesReverseOrder ? -1 : 1;
             for (int i = initial; startInclusive <= i && i <= endInclusive; i += step) {
-                sb.append(Byte.toHexString(bytes[i], true));
+                sb.append(HexEncoding.encodeToString(bytes[i], true));
             }
         } else {
             sb.append(
diff --git a/core/java/android/hardware/location/ContextHubMessage.java b/core/java/android/hardware/location/ContextHubMessage.java
index e1c69d717a8d7..f078ff9444c0a 100644
--- a/core/java/android/hardware/location/ContextHubMessage.java
+++ b/core/java/android/hardware/location/ContextHubMessage.java
@@ -20,6 +20,8 @@ import android.annotation.SystemApi;
 import android.os.Parcel;
 import android.os.Parcelable;
 
+import libcore.util.HexEncoding;
+
 import java.util.Arrays;
 
 /**
@@ -146,7 +148,7 @@ public class ContextHubMessage implements Parcelable {
             ret += "data = 0x";
         }
         for (int i = 0; i < Math.min(length, DEBUG_LOG_NUM_BYTES); i++) {
-            ret += Byte.toHexString(mData[i], true /* upperCase */);
+            ret += HexEncoding.encodeToString(mData[i], true /* upperCase */);
 
             if ((i + 1) % 4 == 0) {
                 ret += " ";
diff --git a/core/java/android/hardware/location/NanoAppMessage.java b/core/java/android/hardware/location/NanoAppMessage.java
index 66352581dac39..fec1f7148a1e9 100644
--- a/core/java/android/hardware/location/NanoAppMessage.java
+++ b/core/java/android/hardware/location/NanoAppMessage.java
@@ -19,6 +19,8 @@ import android.annotation.SystemApi;
 import android.os.Parcel;
 import android.os.Parcelable;
 
+import libcore.util.HexEncoding;
+
 /**
  * A class describing messages send to or from nanoapps through the Context Hub Service.
  *
@@ -155,7 +157,7 @@ public final class NanoAppMessage implements Parcelable {
             ret += "data = 0x";
         }
         for (int i = 0; i < Math.min(length, DEBUG_LOG_NUM_BYTES); i++) {
-            ret += Byte.toHexString(mMessageBody[i], true /* upperCase */);
+            ret += HexEncoding.encodeToString(mMessageBody[i], true /* upperCase */);
 
             if ((i + 1) % 4 == 0) {
                 ret += " ";
diff --git a/core/java/android/security/keystore/recovery/RecoverySession.java b/core/java/android/security/keystore/recovery/RecoverySession.java
index 662271281085f..9166e0beb1667 100644
--- a/core/java/android/security/keystore/recovery/RecoverySession.java
+++ b/core/java/android/security/keystore/recovery/RecoverySession.java
@@ -26,6 +26,8 @@ import android.security.keystore.KeyPermanentlyInvalidatedException;
 import android.util.ArrayMap;
 import android.util.Log;
 
+import libcore.util.HexEncoding;
+
 import java.security.Key;
 import java.security.SecureRandom;
 import java.security.UnrecoverableKeyException;
@@ -71,11 +73,7 @@ public class RecoverySession implements AutoCloseable {
         SecureRandom secureRandom = new SecureRandom();
         byte[] sessionId = new byte[SESSION_ID_LENGTH_BYTES];
         secureRandom.nextBytes(sessionId);
-        StringBuilder sb = new StringBuilder();
-        for (byte b : sessionId) {
-            sb.append(Byte.toHexString(b, /*upperCase=*/ false));
-        }
-        return sb.toString();
+        return HexEncoding.encodeToString(sessionId, /*upperCase=*/ false);
     }
 
     /**
diff --git a/core/java/android/view/ViewDebug.java b/core/java/android/view/ViewDebug.java
index f98541eb111aa..efa1747ebb7b9 100644
--- a/core/java/android/view/ViewDebug.java
+++ b/core/java/android/view/ViewDebug.java
@@ -31,6 +31,8 @@ import android.util.DisplayMetrics;
 import android.util.Log;
 import android.util.TypedValue;
 
+import libcore.util.HexEncoding;
+
 import java.io.BufferedOutputStream;
 import java.io.BufferedWriter;
 import java.io.ByteArrayOutputStream;
@@ -1301,7 +1303,8 @@ public class ViewDebug {
                             if (type == int.class) {
                                 fieldValue = formatIntToHexString((Integer) fieldValue);
                             } else if (type == byte.class) {
-                                fieldValue = "0x" + Byte.toHexString((Byte) fieldValue, true);
+                                fieldValue = "0x"
+                                        + HexEncoding.encodeToString((Byte) fieldValue, true);
                             }
                         }
                     }
diff --git a/services/backup/java/com/android/server/backup/utils/PasswordUtils.java b/services/backup/java/com/android/server/backup/utils/PasswordUtils.java
index a7eb644713ba7..0a7e55146a0a0 100644
--- a/services/backup/java/com/android/server/backup/utils/PasswordUtils.java
+++ b/services/backup/java/com/android/server/backup/utils/PasswordUtils.java
@@ -20,6 +20,8 @@ import static com.android.server.backup.BackupManagerService.TAG;
 
 import android.util.Slog;
 
+import libcore.util.HexEncoding;
+
 import java.security.Key;
 import java.security.NoSuchAlgorithmException;
 import java.security.spec.InvalidKeySpecException;
@@ -74,11 +76,7 @@ public class PasswordUtils {
      * Creates hex string representation of the byte array.
      */
     public static String byteArrayToHex(byte[] data) {
-        StringBuilder buf = new StringBuilder(data.length * 2);
-        for (int i = 0; i < data.length; i++) {
-            buf.append(Byte.toHexString(data[i], true));
-        }
-        return buf.toString();
+        return HexEncoding.encodeToString(data, true);
     }
 
     /**