diff --git a/lib/private/Security/Hasher.php b/lib/private/Security/Hasher.php
index c6c9109b33..e20de729f4 100644
--- a/lib/private/Security/Hasher.php
+++ b/lib/private/Security/Hasher.php
@@ -51,11 +51,9 @@ class Hasher implements IHasher {
 	/** @var IConfig */
 	private $config;
 	/** @var array Options passed to password_hash and password_needs_rehash */
-	private $options = array();
+	private $options = [];
 	/** @var string Salt used for legacy passwords */
 	private $legacySalt = null;
-	/** @var int Current version of the generated hash */
-	private $currentVersion = 1;
 
 	/**
 	 * @param IConfig $config
@@ -78,7 +76,11 @@ class Hasher implements IHasher {
 	 * @return string Hash of the message with appended version parameter
 	 */
 	public function hash(string $message): string {
-		return $this->currentVersion . '|' . password_hash($message, PASSWORD_DEFAULT, $this->options);
+		if (\defined('PASSWORD_ARGON2I')) {
+			return 2 . '|' . password_hash($message, PASSWORD_ARGON2I, $this->options);
+		} else {
+			return 1 . '|' . password_hash($message, PASSWORD_BCRYPT, $this->options);
+		}
 	}
 
 	/**
@@ -90,7 +92,7 @@ class Hasher implements IHasher {
 		$explodedString = explode('|', $prefixedHash, 2);
 		if(\count($explodedString) === 2) {
 			if((int)$explodedString[0] > 0) {
-				return array('version' => (int)$explodedString[0], 'hash' => $explodedString[1]);
+				return ['version' => (int)$explodedString[0], 'hash' => $explodedString[1]];
 			}
 		}
 
@@ -111,8 +113,8 @@ class Hasher implements IHasher {
 
 		// Verify whether it matches a legacy PHPass or SHA1 string
 		$hashLength = \strlen($hash);
-		if($hashLength === 60 && password_verify($message.$this->legacySalt, $hash) ||
-			$hashLength === 40 && hash_equals($hash, sha1($message))) {
+		if(($hashLength === 60 && password_verify($message.$this->legacySalt, $hash)) ||
+			($hashLength === 40 && hash_equals($hash, sha1($message)))) {
 			$newHash = $this->hash($message);
 			return true;
 		}
@@ -121,7 +123,7 @@ class Hasher implements IHasher {
 	}
 
 	/**
-	 * Verify V1 hashes
+	 * Verify V1 (blowfish) hashes
 	 * @param string $message Message to verify
 	 * @param string $hash Assumed hash of the message
 	 * @param null|string &$newHash Reference will contain the updated hash if necessary. Update the existing hash with this one.
@@ -129,7 +131,30 @@ class Hasher implements IHasher {
 	 */
 	protected function verifyHashV1(string $message, string $hash, &$newHash = null): bool {
 		if(password_verify($message, $hash)) {
-			if(password_needs_rehash($hash, PASSWORD_DEFAULT, $this->options)) {
+			$algo = PASSWORD_BCRYPT;
+			if (\defined('PASSWORD_ARGON2I')) {
+				$algo = PASSWORD_ARGON2I;
+			}
+
+			if(password_needs_rehash($hash, $algo, $this->options)) {
+				$newHash = $this->hash($message);
+			}
+			return true;
+		}
+
+		return false;
+	}
+
+	/**
+	 * Verify V2 (argon2i) hashes
+	 * @param string $message Message to verify
+	 * @param string $hash Assumed hash of the message
+	 * @param null|string &$newHash Reference will contain the updated hash if necessary. Update the existing hash with this one.
+	 * @return bool Whether $hash is a valid hash of $message
+	 */
+	protected function verifyHashV2(string $message, string $hash, &$newHash = null) : bool {
+		if(password_verify($message, $hash)) {
+			if(password_needs_rehash($hash, PASSWORD_ARGON2I, $this->options)) {
 				$newHash = $this->hash($message);
 			}
 			return true;
@@ -149,6 +174,8 @@ class Hasher implements IHasher {
 
 		if(isset($splittedHash['version'])) {
 			switch ($splittedHash['version']) {
+				case 2:
+					return $this->verifyHashV2($message, $splittedHash['hash'], $newHash);
 				case 1:
 					return $this->verifyHashV1($message, $splittedHash['hash'], $newHash);
 			}
diff --git a/tests/lib/Security/HasherTest.php b/tests/lib/Security/HasherTest.php
index 86d4ef6ca0..c994b68f78 100644
--- a/tests/lib/Security/HasherTest.php
+++ b/tests/lib/Security/HasherTest.php
@@ -21,52 +21,74 @@ class HasherTest extends \Test\TestCase {
 	 */
 	public function versionHashProvider()
 	{
-		return array(
-			array('asf32äà$$a.|3', null),
-			array('asf32äà$$a.|3|5', null),
-			array('1|2|3|4', array('version' => 1, 'hash' => '2|3|4')),
-			array('1|我看|这本书。 我看這本書', array('version' => 1, 'hash' => '我看|这本书。 我看這本書'))
-		);
+		return [
+			['asf32äà$$a.|3', null],
+			['asf32äà$$a.|3|5', null],
+			['1|2|3|4', ['version' => 1, 'hash' => '2|3|4']],
+			['1|我看|这本书。 我看這本書', ['version' => 1, 'hash' => '我看|这本书。 我看這本書']],
+			['2|newhash', ['version' => 2, 'hash' => 'newhash']],
+		];
 	}
 
 	/**
 	 * @return array
 	 */
-	public function allHashProviders()
+	public function hashProviders70_71()
 	{
-		return array(
+		return [
 			// Valid SHA1 strings
-			array('password', '5baa61e4c9b93f3f0682250b6cf8331b7ee68fd8', true),
-			array('owncloud.com', '27a4643e43046c3569e33b68c1a4b15d31306d29', true),
+			['password', '5baa61e4c9b93f3f0682250b6cf8331b7ee68fd8', true],
+			['owncloud.com', '27a4643e43046c3569e33b68c1a4b15d31306d29', true],
 
 			// Invalid SHA1 strings
-			array('InvalidString', '5baa61e4c9b93f3f0682250b6cf8331b7ee68fd8', false),
-			array('AnotherInvalidOne', '27a4643e43046c3569e33b68c1a4b15d31306d29', false),
+			['InvalidString', '5baa61e4c9b93f3f0682250b6cf8331b7ee68fd8', false],
+			['AnotherInvalidOne', '27a4643e43046c3569e33b68c1a4b15d31306d29', false],
 
 			// Valid legacy password string with password salt "6Wow67q1wZQZpUUeI6G2LsWUu4XKx"
-			array('password', '$2a$08$emCpDEl.V.QwPWt5gPrqrOhdpH6ailBmkj2Hd2vD5U8qIy20HBe7.', true),
-			array('password', '$2a$08$yjaLO4ev70SaOsWZ9gRS3eRSEpHVsmSWTdTms1949mylxJ279hzo2', true),
-			array('password', '$2a$08$.jNRG/oB4r7gHJhAyb.mDupNUAqTnBIW/tWBqFobaYflKXiFeG0A6', true),
-			array('owncloud.com', '$2a$08$YbEsyASX/hXVNMv8hXQo7ezreN17T8Jl6PjecGZvpX.Ayz2aUyaZ2', true),
-			array('owncloud.com', '$2a$11$cHdDA2IkUP28oNGBwlL7jO/U3dpr8/0LIjTZmE8dMPA7OCUQsSTqS', true),
-			array('owncloud.com', '$2a$08$GH.UoIfJ1e.qeZ85KPqzQe6NR8XWRgJXWIUeE1o/j1xndvyTA1x96', true),
+			['password', '$2a$08$emCpDEl.V.QwPWt5gPrqrOhdpH6ailBmkj2Hd2vD5U8qIy20HBe7.', true],
+			['password', '$2a$08$yjaLO4ev70SaOsWZ9gRS3eRSEpHVsmSWTdTms1949mylxJ279hzo2', true],
+			['password', '$2a$08$.jNRG/oB4r7gHJhAyb.mDupNUAqTnBIW/tWBqFobaYflKXiFeG0A6', true],
+			['owncloud.com', '$2a$08$YbEsyASX/hXVNMv8hXQo7ezreN17T8Jl6PjecGZvpX.Ayz2aUyaZ2', true],
+			['owncloud.com', '$2a$11$cHdDA2IkUP28oNGBwlL7jO/U3dpr8/0LIjTZmE8dMPA7OCUQsSTqS', true],
+			['owncloud.com', '$2a$08$GH.UoIfJ1e.qeZ85KPqzQe6NR8XWRgJXWIUeE1o/j1xndvyTA1x96', true],
 
 			// Invalid legacy passwords
-			array('password', '$2a$08$oKAQY5IhnZocP.61MwP7xu7TNeOb7Ostvk3j6UpacvaNMs.xRj7O2', false),
+			['password', '$2a$08$oKAQY5IhnZocP.61MwP7xu7TNeOb7Ostvk3j6UpacvaNMs.xRj7O2', false],
 
 			// Valid passwords "6Wow67q1wZQZpUUeI6G2LsWUu4XKx"
-			array('password', '1|$2a$05$ezAE0dkwk57jlfo6z5Pql.gcIK3ReXT15W7ITNxVS0ksfhO/4E4Kq', true),
-			array('password', '1|$2a$05$4OQmloFW4yTVez2MEWGIleDO9Z5G9tWBXxn1vddogmKBQq/Mq93pe', true),
-			array('password', '1|$2a$11$yj0hlp6qR32G9exGEXktB.yW2rgt2maRBbPgi3EyxcDwKrD14x/WO', true),
-			array('owncloud.com', '1|$2a$10$Yiss2WVOqGakxuuqySv5UeOKpF8d8KmNjuAPcBMiRJGizJXjA2bKm', true),
-			array('owncloud.com', '1|$2a$10$v9mh8/.mF/Ut9jZ7pRnpkuac3bdFCnc4W/gSumheQUi02Sr.xMjPi', true),
-			array('owncloud.com', '1|$2a$05$ST5E.rplNRfDCzRpzq69leRzsTGtY7k88h9Vy2eWj0Ug/iA9w5kGK', true),
+			['password', '1|$2a$05$ezAE0dkwk57jlfo6z5Pql.gcIK3ReXT15W7ITNxVS0ksfhO/4E4Kq', true],
+			['password', '1|$2a$05$4OQmloFW4yTVez2MEWGIleDO9Z5G9tWBXxn1vddogmKBQq/Mq93pe', true],
+			['password', '1|$2a$11$yj0hlp6qR32G9exGEXktB.yW2rgt2maRBbPgi3EyxcDwKrD14x/WO', true],
+			['owncloud.com', '1|$2a$10$Yiss2WVOqGakxuuqySv5UeOKpF8d8KmNjuAPcBMiRJGizJXjA2bKm', true],
+			['owncloud.com', '1|$2a$10$v9mh8/.mF/Ut9jZ7pRnpkuac3bdFCnc4W/gSumheQUi02Sr.xMjPi', true],
+			['owncloud.com', '1|$2a$05$ST5E.rplNRfDCzRpzq69leRzsTGtY7k88h9Vy2eWj0Ug/iA9w5kGK', true],
 
 			// Invalid passwords
-			array('password', '0|$2a$08$oKAQY5IhnZocP.61MwP7xu7TNeOb7Ostvk3j6UpacvaNMs.xRj7O2', false),
-			array('password', '1|$2a$08$oKAQY5IhnZocP.61MwP7xu7TNeOb7Ostvk3j6UpacvaNMs.xRj7O2', false),
-			array('password', '2|$2a$08$oKAQY5IhnZocP.61MwP7xu7TNeOb7Ostvk3j6UpacvaNMs.xRj7O2', false),
-		);
+			['password', '0|$2a$08$oKAQY5IhnZocP.61MwP7xu7TNeOb7Ostvk3j6UpacvaNMs.xRj7O2', false],
+			['password', '1|$2a$08$oKAQY5IhnZocP.61MwP7xu7TNeOb7Ostvk3j6UpacvaNMs.xRj7O2', false],
+			['password', '2|$2a$08$oKAQY5IhnZocP.61MwP7xu7TNeOb7Ostvk3j6UpacvaNMs.xRj7O2', false],
+		];
+	}
+
+
+	/**
+	 * @return array
+	 */
+	public function hashProviders72() {
+		return [
+			// Valid ARGON2 hashes
+			['password', '2|$argon2i$v=19$m=1024,t=2,p=2$T3JGcEkxVFNOVktNSjZUcg$4/hyLtSejxNgAuzSFFV/HLM3qRQKBwEtKw61qPN4zWA', true],
+			['password', '2|$argon2i$v=19$m=1024,t=2,p=2$Zk52V24yNjMzTkhyYjJKOQ$vmqHkCaOD6SiiiFKD1GeKLg/D1ynWpyZbx4XA2yed34', true],
+			['password', '2|$argon2i$v=19$m=1024,t=2,p=2$R1pRcUZKamVlNndBc3l5ag$ToRhR8SiZc7fGMpOYfSc5haS5t9+Y00rljPJV7+qLkM', true],
+			['nextcloud.com', '2|$argon2i$v=19$m=1024,t=2,p=2$NC9xM0FFaDlzM01QM3kudg$fSfndwtO2mKMZlKdsT8XAtPY51cSS6pLSGS3xMqeJhg', true],
+			['nextcloud.com', '2|$argon2i$v=19$m=1024,t=2,p=2$UjkvUjEuL042WWl1cmdHOA$FZivLkBdZnloQsW6qq/jqWK95JSYUHW9rwQC4Ff9GN0', true],
+			['nextcloud.com', '2|$argon2i$v=19$m=1024,t=2,p=2$ZnpNdUlzMEpUTW40OVpiMQ$c+yHT9dtSYsjtVGsa7UKOsxxgQAMiUc781d9WsFACqs', true],
+
+			//Invalid ARGON2 hashes
+			['password', '2|$argon2i$v=19$m=1024,t=2,p=2$UjFDUDg3cjBvM3FkbXVOWQ$7Y5xqFxSERnYn+2+7WChUpWZWMa5BEIhSHWnDgJ71Jk', false],
+			['password', '2|$argon2i$v=19$m=1024,t=2,p=2$ZUxSUi5aQklXdkcyMG1uVA$sYjoSvXg/CS/aS6Xnas/o9a/OPVcGKldzzmuiCD1Fxo', false],
+			['password', '2|$argon2i$v=19$m=1024,t=2,p=2$ZHQ5V0xMOFNmUC52by44Sg$DzQFk3bJTX0J4PVGwW6rMvtnBJRalBkbtpDIXR+d4A0', false],
+		];
 	}
 
 	/** @var Hasher */
@@ -78,13 +100,12 @@ class HasherTest extends \Test\TestCase {
 	protected function setUp() {
 		parent::setUp();
 
-		$this->config = $this->getMockBuilder(IConfig::class)
-			->disableOriginalConstructor()->getMock();
+		$this->config = $this->createMock(IConfig::class);
 
 		$this->hasher = new Hasher($this->config);
 	}
 
-	function testHash() {
+	public function testHash() {
 		$hash = $this->hasher->hash('String To Hash');
 		$this->assertNotNull($hash);
 	}
@@ -92,16 +113,16 @@ class HasherTest extends \Test\TestCase {
 	/**
 	 * @dataProvider versionHashProvider
 	 */
-	function testSplitHash($hash, $expected) {
-		$relativePath = self::invokePrivate($this->hasher, 'splitHash', array($hash));
+	public function testSplitHash($hash, $expected) {
+		$relativePath = self::invokePrivate($this->hasher, 'splitHash', [$hash]);
 		$this->assertSame($expected, $relativePath);
 	}
 
 
 	/**
-	 * @dataProvider allHashProviders
+	 * @dataProvider hashProviders70_71
 	 */
-	function testVerify($password, $hash, $expected) {
+	public function testVerify($password, $hash, $expected) {
 		$this->config
 			->expects($this->any())
 			->method('getSystemValue')
@@ -112,4 +133,33 @@ class HasherTest extends \Test\TestCase {
 		$this->assertSame($expected, $result);
 	}
 
+	/**
+	 * @dataProvider hashProviders72
+	 */
+	public function testVerifyArgon2i($password, $hash, $expected) {
+		if (!\defined('PASSWORD_ARGON2I')) {
+			$this->markTestSkipped('Need ARGON2 support to test ARGON2 hashes');
+		}
+
+		$result = $this->hasher->verify($password, $hash);
+		$this->assertSame($expected, $result);
+	}
+
+	public function testUpgradeHashBlowFishToArgon2i() {
+		if (!\defined('PASSWORD_ARGON2I')) {
+			$this->markTestSkipped('Need ARGON2 support to test ARGON2 hashes');
+		}
+
+		$message = 'mysecret';
+
+		$blowfish = 1 . '|' . password_hash($message, PASSWORD_BCRYPT, []);
+		$argon2i  = 2 . '|' . password_hash($message, PASSWORD_ARGON2I, []);
+
+		$this->assertTrue($this->hasher->verify($message, $blowfish,$newHash));
+		$this->assertTrue($this->hasher->verify($message, $argon2i));
+
+		$relativePath = self::invokePrivate($this->hasher, 'splitHash', [$newHash]);
+
+		$this->assertFalse(password_needs_rehash($relativePath['hash'], PASSWORD_ARGON2I, []));
+	}
 }