diff --git a/tests/Math/BigIntegerTest.php b/tests/Math/BigIntegerTest.php
new file mode 100644
index 00000000..ad0badbc
--- /dev/null
+++ b/tests/Math/BigIntegerTest.php
@@ -0,0 +1,261 @@
+<?php
+/**
+ * @author     Andreas Fischer <bantu@phpbb.com>
+ * @copyright  MMXII Andreas Fischer
+ * @license    http://www.opensource.org/licenses/mit-license.html  MIT License
+ */
+
+require('Math/BigInteger.php');
+
+class BigIntegerTest extends PHPUnit_Framework_TestCase
+{
+	public function getInstance($x = 0, $base = 10)
+	{
+		return new Math_BigInteger($x, $base);
+	}
+
+	public function testConstructorBase2()
+	{
+		// 2**65 = 36893488147419103232
+		$this->assertSame('36893488147419103232', (string) $this->getInstance('1' . str_repeat('0', 65), 2)); 
+	}
+
+	public function testConstructorBase10()
+	{
+		$this->assertSame('18446744073709551616', (string) $this->getInstance('18446744073709551616'));
+	}
+
+	public function testConstructorBase16()
+	{
+		$this->assertSame('50',						(string) $this->getInstance('0x32', 16));
+		$this->assertSame('12345678910',			(string) $this->getInstance('0x2DFDC1C3E', 16));
+		$this->assertSame('18446744073709551615',	(string) $this->getInstance('0xFFFFFFFFFFFFFFFF', 16));
+		$this->assertSame('18446744073709551616',	(string) $this->getInstance('0x10000000000000000', 16));
+	}
+
+	public function testToBytes()
+	{
+		$this->assertSame(chr(65), $this->getInstance('65')->toBytes());
+	}
+
+	public function testToBytesTwosCompliment()
+	{
+		$this->assertSame(chr(126), $this->getInstance('01111110', 2)->toBytes(true));
+	}
+
+	public function testToHex()
+	{
+		 $this->assertSame('41', $this->getInstance('65')->toHex());
+	}
+
+	public function testToBits()
+	{
+		$this->assertSame('1000001', $this->getInstance('65')->toBits());
+	}
+
+	public function testAdd()
+	{
+		$x = $this->getInstance('18446744073709551615');
+		$y = $this->getInstance(        '100000000000');
+
+		$a = $x->add($y);
+		$b = $y->add($x);
+
+		$this->assertTrue($a->equals($b));
+		$this->assertTrue($b->equals($a));
+
+		$this->assertSame('18446744173709551615', (string) $a);
+		$this->assertSame('18446744173709551615', (string) $b);
+	}
+
+	public function testSubtract()
+	{
+		$x = $this->getInstance('18446744073709551618');
+		$y = $this->getInstance(       '4000000000000');
+		$this->assertSame('18446740073709551618', (string) $x->subtract($y));
+	}
+
+	public function testMultiply()
+	{
+		$x = $this->getInstance('8589934592');				// 2**33
+		$y = $this->getInstance('36893488147419103232');	// 2**65
+
+		$a = $x->multiply($y); // 2**98
+		$b = $y->multiply($x); // 2**98
+
+		$this->assertTrue($a->equals($b));
+		$this->assertTrue($b->equals($a));
+
+		$this->assertSame('316912650057057350374175801344', (string) $a);
+		$this->assertSame('316912650057057350374175801344', (string) $b);
+	}
+
+	public function testDivide()
+	{
+		$x = $this->getInstance('1180591620717411303425');	// 2**70 + 1
+		$y = $this->getInstance('12345678910');
+
+		list($q, $r) = $x->divide($y);
+
+		$this->assertSame('95627922070', (string) $q);
+		$this->assertSame('10688759725', (string) $r);
+	}
+
+	public function testModPow()
+	{
+		$a = $this->getInstance('10');
+		$b = $this->getInstance('20');
+		$c = $this->getInstance('30');
+		$d = $a->modPow($b, $c);
+
+		$this->assertSame('10', (string) $d);
+	}
+
+	public function testModInverse()
+	{
+		$a = $this->getInstance(30);
+		$b = $this->getInstance(17);
+
+		$c = $a->modInverse($b);
+		$this->assertSame('4', (string) $c);
+
+		$d = $a->multiply($c);
+		list($q, $r) = $d->divide($b);
+		$this->assertSame('1', (string) $r);
+	}
+
+	public function testExtendedGCD()
+	{
+		$a = $this->getInstance(693);
+		$b = $this->getInstance(609);
+
+		$arr = $a->extendedGCD($b);
+
+		$this->assertSame('21', (string) $arr['gcd']);
+		$this->assertSame(21, $a->toString() * $arr['x']->toString() + $b->toString() * $arr['y']->toString());
+	}
+
+	public function testGCD()
+	{
+		$x = $this->getInstance(693);
+		$y = $this->getInstance(609);
+		$this->assertSame('21', (string) $x->gcd($y));
+	}
+
+	public function testAbs()
+	{
+		$x = $this->getInstance('-18446744073709551617');
+		$y = $x->abs();
+
+		$this->assertSame('-18446744073709551617', (string) $x);
+		$this->assertSame('18446744073709551617', (string) $y);
+	}
+
+	public function testEquals()
+	{
+		$x = $this->getInstance('18446744073709551616');
+		$y = $this->getInstance('18446744073709551616');
+
+		$this->assertTrue($x->equals($y));
+		$this->assertTrue($y->equals($x));
+	}
+
+	public function testCompare()
+	{
+		$a = $this->getInstance('-18446744073709551616');
+		$b = $this->getInstance('36893488147419103232');
+		$c = $this->getInstance('36893488147419103232');
+		$d = $this->getInstance('316912650057057350374175801344');
+
+		// a < b
+		$this->assertLessThan(0, $a->compare($b));
+		$this->assertGreaterThan(0, $b->compare($a));
+
+		// b = c
+		$this->assertSame(0, $b->compare($c));
+		$this->assertSame(0, $c->compare($b));
+
+		// c < d
+		$this->assertLessThan(0, $c->compare($d));
+		$this->assertGreaterThan(0, $d->compare($c));
+	}
+
+	public function testBitwiseAND()
+	{
+		$x = $this->getInstance('66666666666666666666666', 16);
+		$y = $this->getInstance('33333333333333333333333', 16);
+		$z = $this->getInstance('22222222222222222222222', 16);
+
+		$this->assertSame($z->toHex(), $x->bitwise_AND($y)->toHex());
+	}
+
+	public function testBitwiseOR()
+	{
+		$x = $this->getInstance('11111111111111111111111', 16);
+		$y = $this->getInstance('EEEEEEEEEEEEEEEEEEEEEEE', 16);
+		$z = $this->getInstance('FFFFFFFFFFFFFFFFFFFFFFF', 16);
+
+		$this->assertSame($z->toHex(), $x->bitwise_OR($y)->toHex());
+	}
+
+	public function testBitwiseXOR()
+	{
+		$x = $this->getInstance('AFAFAFAFAFAFAFAFAFAFAFAF', 16);
+		$y = $this->getInstance('133713371337133713371337', 16);
+		$z = $this->getInstance('BC98BC98BC98BC98BC98BC98', 16);
+
+		$this->assertSame($z->toHex(), $x->bitwise_XOR($y)->toHex());
+	}
+
+	public function testBitwiseNOT()
+	{
+		$x = $this->getInstance('EEEEEEEEEEEEEEEEEEEEEEE', 16);
+		$z = $this->getInstance('11111111111111111111111', 16);
+
+		$this->assertSame($z->toHex(), $x->bitwise_NOT()->toHex());
+	}
+
+	public function testBitwiseLeftShift()
+	{
+		$x = $this->getInstance('0x0000000FF0000000', 16);
+		$y = $this->getInstance('0x000FF00000000000', 16);
+
+		$this->assertSame($y->toHex(), $x->bitwise_LeftShift(16)->toHex());
+	}
+
+	public function testBitwiseRightShift()
+	{
+		$x = $this->getInstance('0x0000000FF0000000', 16);
+		$y = $this->getInstance('0x00000000000FF000', 16);
+		$z = $this->getInstance('0x000000000000000F', 16);
+		$n = $this->getInstance(0);
+
+		$this->assertSame($y->toHex(), $x->bitwise_RightShift(16)->toHex());
+		$this->assertSame($z->toHex(), $x->bitwise_RightShift(32)->toHex());
+		$this->assertSame($n->toHex(), $x->bitwise_RightShift(36)->toHex());
+	}
+
+	public function testSerializable()
+	{
+		$x = $this->getInstance('18446744073709551616');
+		$y = unserialize(serialize($x));
+
+		$this->assertTrue($x->equals($y));
+		$this->assertTrue($y->equals($x));
+
+		$this->assertSame('18446744073709551616', (string) $x);
+		$this->assertSame('18446744073709551616', (string) $y);
+	}
+
+	public function testClone()
+	{
+		$x = $this->getInstance('18446744073709551616');
+		$y = clone $x;
+
+		$this->assertTrue($x->equals($y));
+		$this->assertTrue($y->equals($x));
+
+		$this->assertSame('18446744073709551616', (string) $x);
+		$this->assertSame('18446744073709551616', (string) $y);
+	}
+}