diff --git a/phpseclib/Crypt/AES.php b/phpseclib/Crypt/AES.php
index 6f0a66ec..5e7153b3 100644
--- a/phpseclib/Crypt/AES.php
+++ b/phpseclib/Crypt/AES.php
@@ -114,13 +114,13 @@ class AES extends Rijndael
             $length = strlen($key);
             switch (true) {
                 case $length <= 16:
-                    $this->key_size = 16;
+                    $this->key_length = 16;
                     break;
                 case $length <= 24:
-                    $this->key_size = 24;
+                    $this->key_length = 24;
                     break;
                 default:
-                    $this->key_size = 32;
+                    $this->key_length = 32;
             }
             $this->_setEngine();
         }
diff --git a/phpseclib/Crypt/Base.php b/phpseclib/Crypt/Base.php
index 520e18dc..b0224e32 100644
--- a/phpseclib/Crypt/Base.php
+++ b/phpseclib/Crypt/Base.php
@@ -378,15 +378,6 @@ abstract class Base
      */
     var $cipher_name_openssl_ecb;
 
-    /**
-     * The default password key_size used by setPassword()
-     *
-     * @see \phpseclib\Crypt\Base::setPassword()
-     * @var int
-     * @access private
-     */
-    var $password_key_size = 32;
-
     /**
      * The default salt used by setPassword()
      *
@@ -553,7 +544,7 @@ abstract class Base
      */
     function getKeyLength()
     {
-        return $this->key_size << 3;
+        return $this->key_length << 3;
     }
 
     /**
@@ -631,7 +622,7 @@ abstract class Base
                 if (isset($func_args[5])) {
                     $dkLen = $func_args[5];
                 } else {
-                    $dkLen = $method == 'pbkdf1' ? 2 * $this->key_size : $this->key_size;
+                    $dkLen = $method == 'pbkdf1' ? 2 * $this->key_length : $this->key_length;
                 }
 
                 switch (true) {
@@ -1893,7 +1884,7 @@ abstract class Base
         $this->encryptIV = $this->decryptIV = str_pad(substr($this->iv, 0, $this->block_size), $this->block_size, "\0");
 
         if (!$this->skip_key_adjustment) {
-            $this->key = str_pad(substr($this->key, 0, $this->key_size), $this->key_size, "\0");
+            $this->key = str_pad(substr($this->key, 0, $this->key_length), $this->key_length, "\0");
         }
     }
 
diff --git a/phpseclib/Crypt/Blowfish.php b/phpseclib/Crypt/Blowfish.php
index 50505378..6d9df3d7 100644
--- a/phpseclib/Crypt/Blowfish.php
+++ b/phpseclib/Crypt/Blowfish.php
@@ -273,17 +273,17 @@ class Blowfish extends Base
     var $kl;
 
     /**
-     * The Key Length
+     * The Key Length (in bytes)
      *
      * @see \phpseclib\Crypt\Base::setKeyLength()
      * @var int
      * @access private
      * @internal The max value is 256 / 8 = 32, the min value is 128 / 8 = 16.  Exists in conjunction with $Nk
-     *    because the encryption / decryption / key schedule creation requires this number and not $key_size.  We could
-     *    derive this from $key_size or vice versa, but that'd mean we'd have to do multiple shift operations, so in lieu
+     *    because the encryption / decryption / key schedule creation requires this number and not $key_length.  We could
+     *    derive this from $key_length or vice versa, but that'd mean we'd have to do multiple shift operations, so in lieu
      *    of that, we'll just precompute it once.
      */
-    var $key_size = 16;
+    var $key_length = 16;
 
     /**
      * Sets the key length.
@@ -296,11 +296,11 @@ class Blowfish extends Base
     function setKeyLength($length)
     {
         if ($length < 32) {
-            $this->key_size = 7;
+            $this->key_length = 7;
         } elseif ($length > 448) {
-            $this->key_size = 56;
+            $this->key_length = 56;
         } else {
-            $this->key_size = $length >> 3;
+            $this->key_length = $length >> 3;
         }
 
         parent::setKeyLength($length);
@@ -319,7 +319,7 @@ class Blowfish extends Base
     function isValidEngine($engine)
     {
         if ($engine == self::ENGINE_OPENSSL) {
-            if ($this->key_size != 16) {
+            if ($this->key_length != 16) {
                 return false;
             }
             $this->cipher_name_openssl_ecb = 'bf-ecb';
diff --git a/phpseclib/Crypt/DES.php b/phpseclib/Crypt/DES.php
index 4a56e26c..23f9045b 100644
--- a/phpseclib/Crypt/DES.php
+++ b/phpseclib/Crypt/DES.php
@@ -78,13 +78,13 @@ class DES extends Base
     var $block_size = 8;
 
     /**
-     * Key Length
+     * Key Length (in bytes)
      *
      * @see \phpseclib\Crypt\Base::setKeyLength()
      * @var int
      * @access private
      */
-    var $key_size = 8;
+    var $key_length = 8;
 
     /**
      * The mcrypt specific name of the cipher
@@ -138,7 +138,7 @@ class DES extends Base
      * @var string
      * @access private
      */
-    var $key_size_max = 8;
+    var $key_length_max = 8;
 
     /**
      * The Key Schedule
@@ -592,7 +592,7 @@ class DES extends Base
      */
     function isValidEngine($engine)
     {
-        if ($this->key_size_max == 8) {
+        if ($this->key_length_max == 8) {
             if ($engine == self::ENGINE_OPENSSL) {
                 $this->cipher_name_openssl_ecb = 'des-ecb';
                 $this->cipher_name_openssl = 'des-' . $this->_openssl_translate_mode();
@@ -621,8 +621,8 @@ class DES extends Base
     {
         // We check/cut here only up to max length of the key.
         // Key padding to the proper length will be done in _setupKey()
-        if (strlen($key) > $this->key_size_max) {
-            $key = substr($key, 0, $this->key_size_max);
+        if (strlen($key) > $this->key_length_max) {
+            $key = substr($key, 0, $this->key_length_max);
         }
 
         // Sets the key
diff --git a/phpseclib/Crypt/RC2.php b/phpseclib/Crypt/RC2.php
index 5f31e002..e6f920af 100644
--- a/phpseclib/Crypt/RC2.php
+++ b/phpseclib/Crypt/RC2.php
@@ -86,13 +86,13 @@ class RC2 extends Base
     var $skip_key_adjustment = true;
 
     /**
-     * Key Length
+     * Key Length (in bytes)
      *
      * @see \phpseclib\Crypt\RC2::setKeyLength()
      * @var int
      * @access private
      */
-    var $key_size = 16; // = 128 bits
+    var $key_length = 16; // = 128 bits
 
     /**
      * The mcrypt specific name of the cipher
diff --git a/phpseclib/Crypt/RC4.php b/phpseclib/Crypt/RC4.php
index 1a6d3bc2..a5db1691 100644
--- a/phpseclib/Crypt/RC4.php
+++ b/phpseclib/Crypt/RC4.php
@@ -76,13 +76,13 @@ class RC4 extends Base
     var $block_size = 0;
 
     /**
-     * Key Length
+     * Key Length (in bytes)
      *
      * @see \phpseclib\Crypt\RC4::setKeyLength()
      * @var int
      * @access private
      */
-    var $key_size = 128; // = 1024 bits
+    var $key_length = 128; // = 1024 bits
 
     /**
      * The mcrypt specific name of the cipher
@@ -200,11 +200,11 @@ class RC4 extends Base
     function setKeyLength($length)
     {
         if ($length < 8) {
-            $this->key_size = 1;
+            $this->key_length = 1;
         } elseif ($length > 2048) {
-            $this->key_size = 248;
+            $this->key_length = 248;
         } else {
-            $this->key_size = $length >> 3;
+            $this->key_length = $length >> 3;
         }
 
         parent::setKeyLength($length);
diff --git a/phpseclib/Crypt/Rijndael.php b/phpseclib/Crypt/Rijndael.php
index 079bd52d..334eaf9d 100644
--- a/phpseclib/Crypt/Rijndael.php
+++ b/phpseclib/Crypt/Rijndael.php
@@ -68,9 +68,9 @@ class Rijndael extends Base
     /**
      * The mcrypt specific name of the cipher
      *
-     * Mcrypt is useable for 128/192/256-bit $block_size/$key_size. For 160/224 not.
+     * Mcrypt is useable for 128/192/256-bit $block_size/$key_length. For 160/224 not.
      * \phpseclib\Crypt\Rijndael determines automatically whether mcrypt is useable
-     * or not for the current $block_size/$key_size.
+     * or not for the current $block_size/$key_length.
      * In case of, $cipher_name_mcrypt will be set dynamically at run time accordingly.
      *
      * @see \phpseclib\Crypt\Base::cipher_name_mcrypt
@@ -123,17 +123,17 @@ class Rijndael extends Base
     var $Nb = 4;
 
     /**
-     * The Key Length
+     * The Key Length (in bytes)
      *
      * @see setKeyLength()
      * @var int
      * @access private
      * @internal The max value is 256 / 8 = 32, the min value is 128 / 8 = 16.  Exists in conjunction with $Nk
-     *    because the encryption / decryption / key schedule creation requires this number and not $key_size.  We could
-     *    derive this from $key_size or vice versa, but that'd mean we'd have to do multiple shift operations, so in lieu
+     *    because the encryption / decryption / key schedule creation requires this number and not $key_length.  We could
+     *    derive this from $key_length or vice versa, but that'd mean we'd have to do multiple shift operations, so in lieu
      *    of that, we'll just precompute it once.
      */
-    var $key_size = 16;
+    var $key_length = 16;
 
     /**
      * The Key Length divided by 32
@@ -194,19 +194,19 @@ class Rijndael extends Base
     {
         switch (true) {
             case $length <= 128:
-                $this->key_size = 16;
+                $this->key_length = 16;
                 break;
             case $length <= 160:
-                $this->key_size = 20;
+                $this->key_length = 20;
                 break;
             case $length <= 192:
-                $this->key_size = 24;
+                $this->key_length = 24;
                 break;
             case $length <= 224:
-                $this->key_size = 28;
+                $this->key_length = 28;
                 break;
             default:
-                $this->key_size = 32;
+                $this->key_length = 32;
         }
 
         parent::setKeyLength($length);
@@ -252,12 +252,12 @@ class Rijndael extends Base
                 if ($this->block_size != 16) {
                     return false;
                 }
-                $this->cipher_name_openssl_ecb = 'aes-' . ($this->key_size << 3) . '-ecb';
-                $this->cipher_name_openssl = 'aes-' . ($this->key_size << 3) . '-' . $this->_openssl_translate_mode();
+                $this->cipher_name_openssl_ecb = 'aes-' . ($this->key_length << 3) . '-ecb';
+                $this->cipher_name_openssl = 'aes-' . ($this->key_length << 3) . '-' . $this->_openssl_translate_mode();
                 break;
             case self::ENGINE_MCRYPT:
                 $this->cipher_name_mcrypt = 'rijndael-' . ($this->block_size << 3);
-                if ($this->key_size % 8) { // is it a 160/224-bit key?
+                if ($this->key_length % 8) { // is it a 160/224-bit key?
                     // mcrypt is not usable for them, only for 128/192/256-bit keys
                     return false;
                 }
@@ -476,13 +476,13 @@ class Rijndael extends Base
             0x7D000000, 0xFA000000, 0xEF000000, 0xC5000000, 0x91000000
         );
 
-        if (isset($this->kl['key']) && $this->key === $this->kl['key'] && $this->key_size === $this->kl['key_size'] && $this->block_size === $this->kl['block_size']) {
+        if (isset($this->kl['key']) && $this->key === $this->kl['key'] && $this->key_length === $this->kl['key_length'] && $this->block_size === $this->kl['block_size']) {
             // already expanded
             return;
         }
-        $this->kl = array('key' => $this->key, 'key_size' => $this->key_size, 'block_size' => $this->block_size);
+        $this->kl = array('key' => $this->key, 'key_length' => $this->key_length, 'block_size' => $this->block_size);
 
-        $this->Nk = $this->key_size >> 2;
+        $this->Nk = $this->key_length >> 2;
         // see Rijndael-ammended.pdf#page=44
         $this->Nr = max($this->Nk, $this->Nb) + 6;
 
diff --git a/phpseclib/Crypt/TripleDES.php b/phpseclib/Crypt/TripleDES.php
index d1389e3f..c5a0229e 100644
--- a/phpseclib/Crypt/TripleDES.php
+++ b/phpseclib/Crypt/TripleDES.php
@@ -64,13 +64,13 @@ class TripleDES extends DES
     const MODE_CBC3 = Base::MODE_CBC;
 
     /**
-     * Key Length
+     * Key Length (in bytes)
      *
      * @see \phpseclib\Crypt\TripleDES::setKeyLength()
      * @var int
      * @access private
      */
-    var $key_size = 24;
+    var $key_length = 24;
 
     /**
      * The default salt used by setPassword()
@@ -109,7 +109,7 @@ class TripleDES extends DES
      * @var string
      * @access private
      */
-    var $key_size_max = 24;
+    var $key_length_max = 24;
 
     /**
      * Internal flag whether using self::MODE_3CBC or not
@@ -237,13 +237,13 @@ class TripleDES extends DES
         $length >>= 3;
         switch (true) {
             case $length <= 8:
-                $this->key_size = 8;
+                $this->key_length = 8;
                 break;
             case $length <= 16:
-                $this->key_size = 16;
+                $this->key_length = 16;
                 break;
             default:
-                $this->key_size = 24;
+                $this->key_length = 24;
         }
 
         parent::setKeyLength($length);
@@ -266,7 +266,7 @@ class TripleDES extends DES
      */
     function setKey($key)
     {
-        $length = $this->explicit_key_length ? $this->key_size : strlen($key);
+        $length = $this->explicit_key_length ? $this->key_length : strlen($key);
         if ($length > 8) {
             $key = str_pad(substr($key, 0, 24), 24, chr(0));
             // if $key is between 64 and 128-bits, use the first 64-bits as the last, per this:
diff --git a/phpseclib/Crypt/Twofish.php b/phpseclib/Crypt/Twofish.php
index 91033295..623e9a6a 100644
--- a/phpseclib/Crypt/Twofish.php
+++ b/phpseclib/Crypt/Twofish.php
@@ -361,6 +361,15 @@ class Twofish extends Base
      */
     var $kl;
 
+    /**
+     * The Key Length (in bytes)
+     *
+     * @see Crypt_Twofish::setKeyLength()
+     * @var int
+     * @access private
+     */
+    var $key_length = 16;
+
     /**
      * Sets the key length.
      *
@@ -373,13 +382,13 @@ class Twofish extends Base
     {
         switch (true) {
             case $length <= 128:
-                $this->key_size = 16;
+                $this->key_length = 16;
                 break;
             case $length <= 192:
-                $this->key_size = 24;
+                $this->key_length = 24;
                 break;
             default:
-                $this->key_size = 32;
+                $this->key_length = 32;
         }
 
         parent::setKeyLength($length);