diff --git a/appveyor.yml b/appveyor.yml
deleted file mode 100644
index 210a9034..00000000
--- a/appveyor.yml
+++ /dev/null
@@ -1,27 +0,0 @@
-build: false
-shallow_clone: false
-platform:
-  - x86
-  - x64
-clone_folder: C:\projects\phpseclib
-
-install:
-  - cinst -y OpenSSL.Light
-  - SET PATH=C:\Program Files\OpenSSL;%PATH%
-  - sc config wuauserv start= auto
-  - net start wuauserv
-  - cinst -y php --version 5.6.30
-  - cd c:\tools\php56
-  - copy php.ini-production php.ini
-  - echo date.timezone="UTC" >> php.ini
-  - echo extension_dir=ext >> php.ini
-  - echo extension=php_openssl.dll >> php.ini
-  - echo extension=php_gmp.dll >> php.ini
-  - cd C:\projects\phpseclib
-  - SET PATH=C:\tools\php56;%PATH%
-  - php.exe -r "readfile('http://getcomposer.org/installer');" | php.exe
-  - php.exe composer.phar install --prefer-source --no-interaction
-
-test_script:
-  - cd C:\projects\phpseclib
-  - vendor\bin\phpunit.bat tests/Windows32Test.php
\ No newline at end of file
diff --git a/phpseclib/Math/BigInteger.php b/phpseclib/Math/BigInteger.php
index 9365d5cf..adf50838 100644
--- a/phpseclib/Math/BigInteger.php
+++ b/phpseclib/Math/BigInteger.php
@@ -40,7 +40,7 @@ use phpseclib3\Math\BigInteger\Engines\Engine;
  * @author  Jim Wigginton <terrafrost@php.net>
  * @access  public
  */
-class BigInteger
+class BigInteger implements \JsonSerializable
 {
     /**
      * Main Engine
@@ -438,6 +438,20 @@ class BigInteger
         }
     }
 
+    /**
+     * JSON Serialize
+     *
+     * Will be called, automatically, when json_encode() is called on a BigInteger object.
+     */
+    public function jsonSerialize()
+    {
+        $result = ['hex' => $this->toHex(true)];
+        if ($this->precision > 0) {
+            $result['precision'] = $this->getPrecision();
+        }
+        return $result;
+    }
+
     /**
      * Performs modular exponentiation.
      *
diff --git a/phpseclib/Math/BigInteger/Engines/BCMath.php b/phpseclib/Math/BigInteger/Engines/BCMath.php
index cc3ff79e..db30a87f 100644
--- a/phpseclib/Math/BigInteger/Engines/BCMath.php
+++ b/phpseclib/Math/BigInteger/Engines/BCMath.php
@@ -663,7 +663,7 @@ class BCMath extends Engine
     public function testBit($x)
     {
         return bccomp(
-            bcmod($this->value, bcpow('2', $x + 1, 0), 0),
+            bcmod($this->value, bcpow('2', $x + 1, 0)),
             bcpow('2', $x, 0),
             0
         ) >= 0;
diff --git a/phpseclib/Math/BigInteger/Engines/Engine.php b/phpseclib/Math/BigInteger/Engines/Engine.php
index 6c152202..fe6bff80 100644
--- a/phpseclib/Math/BigInteger/Engines/Engine.php
+++ b/phpseclib/Math/BigInteger/Engines/Engine.php
@@ -28,7 +28,7 @@ use phpseclib3\Math\BigInteger;
  * @author  Jim Wigginton <terrafrost@php.net>
  * @access  public
  */
-abstract class Engine
+abstract class Engine implements \JsonSerializable
 {
     /* final protected */ const PRIMES = [
         3,   5,   7,   11,  13,  17,  19,  23,  29,  31,  37,  41,  43,  47,  53,  59,
@@ -371,6 +371,20 @@ abstract class Engine
         }
     }
 
+    /**
+     * JSON Serialize
+     *
+     * Will be called, automatically, when json_encode() is called on a BigInteger object.
+     */
+    public function jsonSerialize()
+    {
+        $result = ['hex' => $this->toHex(true)];
+        if ($this->precision > 0) {
+            $result['precision'] = $this->precision;
+        }
+        return $result;
+    }
+
     /**
      * Converts a BigInteger to a base-10 number.
      *
diff --git a/phpseclib/Math/BigInteger/Engines/PHP.php b/phpseclib/Math/BigInteger/Engines/PHP.php
index 3844a928..b363083d 100644
--- a/phpseclib/Math/BigInteger/Engines/PHP.php
+++ b/phpseclib/Math/BigInteger/Engines/PHP.php
@@ -771,6 +771,8 @@ abstract class PHP extends Engine
             for ($i = 0; $i < $length; ++$i) {
                 $value[$i] = $value[$i] & $result->bitmask->value[$i];
             }
+
+            $value = static::trim($value);
         }
 
         return $result;
diff --git a/phpseclib/Math/BigInteger/Engines/PHP/Reductions/EvalBarrett.php b/phpseclib/Math/BigInteger/Engines/PHP/Reductions/EvalBarrett.php
index e5712b0e..5360aebc 100644
--- a/phpseclib/Math/BigInteger/Engines/PHP/Reductions/EvalBarrett.php
+++ b/phpseclib/Math/BigInteger/Engines/PHP/Reductions/EvalBarrett.php
@@ -283,6 +283,7 @@ abstract class EvalBarrett extends Base
                 $sum = $' . $result . '[$i] + $_' . $y . '[$i] + $carry;
                 $carry = $sum >= ' . self::float2string($class::BASE_FULL) . ';
                 $' . $result . '[$i] = $carry ? $sum - ' . self::float2string($class::BASE_FULL) . ' : $sum;
+                ++$i;
             }
             if ($carry) {
                 for (; $' . $result . '[$i] == ' . $class::MAX_DIGIT . '; ++$i) {
diff --git a/phpseclib/Math/Common/FiniteField/Integer.php b/phpseclib/Math/Common/FiniteField/Integer.php
index ab968e26..120026e7 100644
--- a/phpseclib/Math/Common/FiniteField/Integer.php
+++ b/phpseclib/Math/Common/FiniteField/Integer.php
@@ -21,6 +21,25 @@ namespace phpseclib3\Math\Common\FiniteField;
  * @author  Jim Wigginton <terrafrost@php.net>
  * @access  public
  */
-abstract class Integer
+abstract class Integer implements \JsonSerializable
 {
+    /**
+     * JSON Serialize
+     *
+     * Will be called, automatically, when json_encode() is called on a BigInteger object.
+     *
+     * PHP Serialize isn't supported because unserializing would require the factory be
+     * serialized as well and that just sounds like too much
+     */
+    public function jsonSerialize()
+    {
+        return ['hex' => $this->toHex(true)];
+    }
+
+    /**
+     * Converts an Integer to a hex string (eg. base-16).
+     *
+     * @return string
+     */
+    abstract public function toHex();
 }