diff --git a/src/Alg/Encryption/EncryptionAlgorithmFactory.php b/src/Alg/Encryption/EncryptionAlgorithmFactory.php
index ce9475b4..7b1c9111 100644
--- a/src/Alg/Encryption/EncryptionAlgorithmFactory.php
+++ b/src/Alg/Encryption/EncryptionAlgorithmFactory.php
@@ -42,7 +42,7 @@ final class EncryptionAlgorithmFactory
      *
      * @var string[]
      */
-    private const DEFAULT_BLACKLIST = [
+    public const DEFAULT_BLACKLIST = [
         C::BLOCK_ENC_3DES,
     ];
 
diff --git a/src/Alg/KeyTransport/KeyTransportAlgorithmFactory.php b/src/Alg/KeyTransport/KeyTransportAlgorithmFactory.php
index 79cccafd..887542f7 100644
--- a/src/Alg/KeyTransport/KeyTransportAlgorithmFactory.php
+++ b/src/Alg/KeyTransport/KeyTransportAlgorithmFactory.php
@@ -40,7 +40,7 @@ class KeyTransportAlgorithmFactory
      *
      * @var string[]
      */
-    private const DEFAULT_BLACKLIST = [
+    public const DEFAULT_BLACKLIST = [
         C::KEY_TRANSPORT_RSA_1_5,
     ];
 
diff --git a/src/Alg/Signature/SignatureAlgorithmFactory.php b/src/Alg/Signature/SignatureAlgorithmFactory.php
index 8dbb806a..6d24e70f 100644
--- a/src/Alg/Signature/SignatureAlgorithmFactory.php
+++ b/src/Alg/Signature/SignatureAlgorithmFactory.php
@@ -42,7 +42,7 @@ final class SignatureAlgorithmFactory
      *
      * @var string[]
      */
-    private const DEFAULT_BLACKLIST = [
+    public const DEFAULT_BLACKLIST = [
         C::SIG_RSA_SHA1,
         C::SIG_HMAC_SHA1,
     ];