diff --git a/phpseclib/Crypt/Common/SymmetricKey.php b/phpseclib/Crypt/Common/SymmetricKey.php
index ea3a4c27..63e1381a 100644
--- a/phpseclib/Crypt/Common/SymmetricKey.php
+++ b/phpseclib/Crypt/Common/SymmetricKey.php
@@ -263,6 +263,11 @@ abstract class SymmetricKey
      */
     protected $debuffer;
 
+    /**
+     * @var array
+     */
+    protected $buffer;
+
     /**
      * Does internal cipher state need to be (re)initialized?
      *
diff --git a/phpseclib/Crypt/DES.php b/phpseclib/Crypt/DES.php
index c7d089dc..ee2f04ee 100644
--- a/phpseclib/Crypt/DES.php
+++ b/phpseclib/Crypt/DES.php
@@ -124,6 +124,11 @@ class DES extends BlockCipher
      */
     private $keys;
 
+    /**
+     * @var array
+     */
+    private $kl;
+
     /**
      * Shuffle table.
      *
diff --git a/phpseclib/Crypt/DH/PublicKey.php b/phpseclib/Crypt/DH/PublicKey.php
index b52b3d78..583b3b2e 100644
--- a/phpseclib/Crypt/DH/PublicKey.php
+++ b/phpseclib/Crypt/DH/PublicKey.php
@@ -15,6 +15,7 @@ namespace phpseclib3\Crypt\DH;
 
 use phpseclib3\Crypt\Common;
 use phpseclib3\Crypt\DH;
+use phpseclib3\Math\BigInteger;
 
 /**
  * DH Public Key
@@ -25,6 +26,13 @@ class PublicKey extends DH
 {
     use Common\Traits\Fingerprint;
 
+    /**
+     * Public Key
+     *
+     * @var BigInteger
+     */
+    protected $publicKey;
+
     /**
      * Returns the public key
      *
@@ -40,7 +48,7 @@ class PublicKey extends DH
     /**
      * Returns the public key as a BigInteger
      */
-    public function toBigInteger(): \phpseclib3\Math\BigInteger
+    public function toBigInteger(): BigInteger
     {
         return $this->publicKey;
     }
diff --git a/phpseclib/Crypt/EC.php b/phpseclib/Crypt/EC.php
index 3f61916d..835d75fe 100644
--- a/phpseclib/Crypt/EC.php
+++ b/phpseclib/Crypt/EC.php
@@ -125,6 +125,11 @@ abstract class EC extends AsymmetricKey
      */
     protected $context;
 
+    /**
+     * @var string
+     */
+    protected $sigFormat;
+
     /**
      * Create public / private key pair.
      */
diff --git a/phpseclib/Crypt/EC/Curves/secp160k1.php b/phpseclib/Crypt/EC/Curves/secp160k1.php
index 6a4d273c..02a461a5 100644
--- a/phpseclib/Crypt/EC/Curves/secp160k1.php
+++ b/phpseclib/Crypt/EC/Curves/secp160k1.php
@@ -20,6 +20,10 @@ use phpseclib3\Math\BigInteger;
 
 class secp160k1 extends KoblitzPrime
 {
+    public $basis;
+
+    public $beta;
+
     public function __construct()
     {
         // same as secp160r2
diff --git a/phpseclib/Crypt/EC/Curves/secp192k1.php b/phpseclib/Crypt/EC/Curves/secp192k1.php
index 952c56e0..ee97b193 100644
--- a/phpseclib/Crypt/EC/Curves/secp192k1.php
+++ b/phpseclib/Crypt/EC/Curves/secp192k1.php
@@ -20,6 +20,10 @@ use phpseclib3\Math\BigInteger;
 
 class secp192k1 extends KoblitzPrime
 {
+    public $basis;
+
+    public $beta;
+
     public function __construct()
     {
         $this->setModulo(new BigInteger('FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFEE37', 16));
diff --git a/phpseclib/Crypt/EC/Curves/secp224k1.php b/phpseclib/Crypt/EC/Curves/secp224k1.php
index bf45dc82..f62df8cf 100644
--- a/phpseclib/Crypt/EC/Curves/secp224k1.php
+++ b/phpseclib/Crypt/EC/Curves/secp224k1.php
@@ -20,6 +20,10 @@ use phpseclib3\Math\BigInteger;
 
 class secp224k1 extends KoblitzPrime
 {
+    public $basis;
+
+    public $beta;
+
     public function __construct()
     {
         $this->setModulo(new BigInteger('FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFE56D', 16));
diff --git a/phpseclib/Crypt/EC/Curves/secp256k1.php b/phpseclib/Crypt/EC/Curves/secp256k1.php
index e886e592..6463727c 100644
--- a/phpseclib/Crypt/EC/Curves/secp256k1.php
+++ b/phpseclib/Crypt/EC/Curves/secp256k1.php
@@ -24,6 +24,10 @@ use phpseclib3\Math\BigInteger;
 //class secp256k1 extends Prime
 class secp256k1 extends KoblitzPrime
 {
+    public $basis;
+
+    public $beta;
+
     public function __construct()
     {
         $this->setModulo(new BigInteger('FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFC2F', 16));
diff --git a/phpseclib/Crypt/Hash.php b/phpseclib/Crypt/Hash.php
index 5efacabb..af270574 100644
--- a/phpseclib/Crypt/Hash.php
+++ b/phpseclib/Crypt/Hash.php
@@ -170,6 +170,11 @@ class Hash
      */
     private $pad;
 
+    /**
+     * @var int
+     */
+    private $blockSize;
+
     /**#@+
      * UMAC variables
      *
diff --git a/phpseclib/Crypt/RSA/PrivateKey.php b/phpseclib/Crypt/RSA/PrivateKey.php
index e7e618e6..a7dcad6a 100644
--- a/phpseclib/Crypt/RSA/PrivateKey.php
+++ b/phpseclib/Crypt/RSA/PrivateKey.php
@@ -55,6 +55,11 @@ class PrivateKey extends RSA implements Common\PrivateKey
      */
     protected $publicExponent = false;
 
+    /**
+     * Private Exponent
+     */
+    protected $privateExponent;
+
     /**
      * RSADP
      *
diff --git a/phpseclib/Crypt/RSA/PublicKey.php b/phpseclib/Crypt/RSA/PublicKey.php
index c20f08fd..0b9e39f2 100644
--- a/phpseclib/Crypt/RSA/PublicKey.php
+++ b/phpseclib/Crypt/RSA/PublicKey.php
@@ -34,6 +34,16 @@ class PublicKey extends RSA implements Common\PublicKey
 {
     use Common\Traits\Fingerprint;
 
+    /**
+     * Public Exponent
+     */
+    protected $publicExponent = false;
+
+    /**
+     * Private Exponent
+     */
+    protected $privateExponent;
+
     /**
      * Exponentiate
      */
diff --git a/phpseclib/Math/BigInteger.php b/phpseclib/Math/BigInteger.php
index 88860838..8b3e7e76 100644
--- a/phpseclib/Math/BigInteger.php
+++ b/phpseclib/Math/BigInteger.php
@@ -79,6 +79,11 @@ class BigInteger implements \JsonSerializable
      */
     private $precision;
 
+    /**
+     * @var string
+     */
+    public $secret;
+
     /**
      * Sets engine type.
      *
diff --git a/phpseclib/Math/BigInteger/Engines/PHP/Reductions/EvalBarrett.php b/phpseclib/Math/BigInteger/Engines/PHP/Reductions/EvalBarrett.php
index ce709785..607dd060 100644
--- a/phpseclib/Math/BigInteger/Engines/PHP/Reductions/EvalBarrett.php
+++ b/phpseclib/Math/BigInteger/Engines/PHP/Reductions/EvalBarrett.php
@@ -57,7 +57,7 @@ abstract class EvalBarrett extends Base
                 $lhs->value = $x;
                 $rhs = new ' . $class . '();
                 $rhs->value = [' .
-                implode(',', array_map('self::float2string', $m->value)) . '];
+                implode(',', array_map(self::class . '::float2string', $m->value)) . '];
                 list(, $temp) = $lhs->divide($rhs);
                 return $temp->value;
             ';
@@ -98,7 +98,7 @@ abstract class EvalBarrett extends Base
                 $rhs = new ' . $class . '();
                 $lhs->value = $n;
                 $rhs->value = [' .
-                implode(',', array_map('self::float2string', $m)) . '];
+                implode(',', array_map(self::class . '::float2string', $m)) . '];
                 list(, $temp) = $lhs->divide($rhs);
                 return $temp->value;
             }
diff --git a/phpseclib/Math/BinaryField/Integer.php b/phpseclib/Math/BinaryField/Integer.php
index b6bb12c8..40750b22 100644
--- a/phpseclib/Math/BinaryField/Integer.php
+++ b/phpseclib/Math/BinaryField/Integer.php
@@ -62,6 +62,11 @@ class Integer extends Base
      */
     protected static $reduce;
 
+    /**
+     * @var bool|string
+     */
+    public $key;
+
     /**
      * Default constructor
      */
diff --git a/phpseclib/Math/PrimeField.php b/phpseclib/Math/PrimeField.php
index 0b21a82b..0b49c517 100644
--- a/phpseclib/Math/PrimeField.php
+++ b/phpseclib/Math/PrimeField.php
@@ -41,6 +41,11 @@ class PrimeField extends FiniteField
      */
     protected $instanceID;
 
+    /**
+     * @var BigInteger
+     */
+    protected $modulo;
+
     /**
      * Default constructor
      */