diff --git a/CHANGELOG.md b/CHANGELOG.md
index 11601a0..4c8abad 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [3.5.3] - 2025-08-12
+### Added
+- Rename `AuthenticationResult` property to `Authentication` in `Transaction` class.
+
 ## [3.5.2] - 2025-08-08
 ### Added
 - Correct `Transaction` `CreditCardExpiry` type.
diff --git a/src/AbstractApi.php b/src/AbstractApi.php
index 2620c21..d5eba3f 100644
--- a/src/AbstractApi.php
+++ b/src/AbstractApi.php
@@ -55,7 +55,7 @@ abstract class AbstractApi
     /**
      * PHP API version
      */
-    const PHP_API_VERSION = '3.5.2';
+    const PHP_API_VERSION = '3.5.3';
 
     /**
      * Event dispatcher
diff --git a/src/Response/Embeds/AuthenticationResult.php b/src/Response/Embeds/Authentication.php
similarity index 95%
rename from src/Response/Embeds/AuthenticationResult.php
rename to src/Response/Embeds/Authentication.php
index d3f5ebd..a9d0ef3 100644
--- a/src/Response/Embeds/AuthenticationResult.php
+++ b/src/Response/Embeds/Authentication.php
@@ -25,7 +25,7 @@
 
 use Altapay\Response\AbstractResponse;
 
-class AuthenticationResult extends AbstractResponse
+class Authentication extends AbstractResponse
 {
     /**
      * @var "CHALLENGE"|"FRICTIONLESS"|"UNKNOWN"
@@ -50,7 +50,7 @@ class AuthenticationResult extends AbstractResponse
     public $Version;
 
     /**
-     * @var "3DSECURE"
+     * @var "3DSECURE"|"UNKNOWN"
      */
     public $Type;
 }
diff --git a/src/Response/Embeds/Transaction.php b/src/Response/Embeds/Transaction.php
index e356360..ecab8ba 100644
--- a/src/Response/Embeds/Transaction.php
+++ b/src/Response/Embeds/Transaction.php
@@ -63,8 +63,8 @@ class Transaction extends AbstractResponse
             'class' => CardInformation::class,
             'array' => false
         ],
-        'AuthenticationResult'     => [
-            'class' => AuthenticationResult::class,
+        'Authentication'     => [
+            'class' => Authentication::class,
             'array' => false
         ]
     ];
@@ -290,10 +290,16 @@ class Transaction extends AbstractResponse
     public $InvoiceOrderInfo;
 
     /**
-     * @var AuthenticationResult
+     * @var Authentication
+     * @deprecated Use $Authentication instead.
      */
     public $AuthenticationResult;
 
+    /**
+     * @var Authentication
+     */
+    public $Authentication;
+
     /**
      * @var DateTime
      */