diff --git a/apps/federation/appinfo/database.xml b/apps/federation/appinfo/database.xml
index 05b7fb12b4946388a6defda9c1629d4c43a8151b..61c3b8ac6d8d8d1c2c6d70fbb078ccd484563e11 100644
--- a/apps/federation/appinfo/database.xml
+++ b/apps/federation/appinfo/database.xml
@@ -27,8 +27,7 @@
 				<type>text</type>
 				<default></default>
 				<notnull>true</notnull>
-				<length>32</length>
-				<comments>md5 hash of the url without the protocol</comments>
+				<comments>sha1 hash of the url without the protocol</comments>
 			</field>
 			<field>
 				<name>token</name>
diff --git a/apps/federation/lib/dbhandler.php b/apps/federation/lib/dbhandler.php
index 3ea84baa3eb9b74de0bbf592a4984a163a1e5126..df36228c760ea2dd23d0c5e82c5970e951bf2458 100644
--- a/apps/federation/lib/dbhandler.php
+++ b/apps/federation/lib/dbhandler.php
@@ -112,7 +112,7 @@ class DbHandler {
 	 */
 	public function getAllServer() {
 		$query = $this->connection->getQueryBuilder();
-		$query->select(['url', 'id', 'status', 'shared_secret', 'sync_token'])->from($this->dbTable);
+		$query->select(['url', 'url_hash', 'id', 'status', 'shared_secret', 'sync_token'])->from($this->dbTable);
 		$result = $query->execute()->fetchAll();
 		return $result;
 	}
@@ -252,11 +252,11 @@ class DbHandler {
 	 */
 	protected function hash($url) {
 		$normalized = $this->normalizeUrl($url);
-		return md5($normalized);
+		return sha1($normalized);
 	}
 
 	/**
-	 * normalize URL, used to create the md5 hash
+	 * normalize URL, used to create the sha1 hash
 	 *
 	 * @param string $url
 	 * @return string
diff --git a/apps/federation/lib/syncfederationaddressbooks.php b/apps/federation/lib/syncfederationaddressbooks.php
index 6419fdddf8e39ba5ad2bd8c7354c5b72d87c335d..886f6505b20773c135ad20b2991fa3cb2e5ef369 100644
--- a/apps/federation/lib/syncfederationaddressbooks.php
+++ b/apps/federation/lib/syncfederationaddressbooks.php
@@ -40,7 +40,7 @@ class SyncFederationAddressBooks {
 			if (is_null($sharedSecret)) {
 				continue;
 			}
-			$targetBookId = sha1($url);
+			$targetBookId = $trustedServer['url_hash'];
 			$targetPrincipal = "principals/system/system";
 			$targetBookProperties = [
 					'{DAV:}displayname' => $url
diff --git a/apps/federation/tests/lib/dbhandlertest.php b/apps/federation/tests/lib/dbhandlertest.php
index 6fe5d9ea8efc1a8cfdba50ae631a2857f5f3e4d3..ee28da8e02aadcee51bc0c41b0adba4da8834fd2 100644
--- a/apps/federation/tests/lib/dbhandlertest.php
+++ b/apps/federation/tests/lib/dbhandlertest.php
@@ -89,9 +89,9 @@ class DbHandlerTest extends TestCase {
 
 	public function dataTestAddServer() {
 		return [
-				['http://owncloud.org', 'http://owncloud.org', md5('owncloud.org')],
-				['https://owncloud.org', 'https://owncloud.org', md5('owncloud.org')],
-				['http://owncloud.org/', 'http://owncloud.org', md5('owncloud.org')],
+				['http://owncloud.org', 'http://owncloud.org', sha1('owncloud.org')],
+				['https://owncloud.org', 'https://owncloud.org', sha1('owncloud.org')],
+				['http://owncloud.org/', 'http://owncloud.org', sha1('owncloud.org')],
 		];
 	}
 
@@ -233,10 +233,10 @@ class DbHandlerTest extends TestCase {
 
 	public function dataTestHash() {
 		return [
-			['server1', md5('server1')],
-			['http://server1', md5('server1')],
-			['https://server1', md5('server1')],
-			['http://server1/', md5('server1')],
+			['server1', sha1('server1')],
+			['http://server1', sha1('server1')],
+			['https://server1', sha1('server1')],
+			['http://server1/', sha1('server1')],
 		];
 	}
 
diff --git a/apps/federation/tests/lib/syncfederationaddressbookstest.php b/apps/federation/tests/lib/syncfederationaddressbookstest.php
index 770896535faa61b526d2bd7b07bad75e79dd876d..9290bad8bd67aa861f8e8c8562c7104a5b55e982 100644
--- a/apps/federation/tests/lib/syncfederationaddressbookstest.php
+++ b/apps/federation/tests/lib/syncfederationaddressbookstest.php
@@ -19,6 +19,7 @@ class SyncFederationAddressbooksTest extends \Test\TestCase {
 			willReturn([
 			[
 				'url' => 'https://cloud.drop.box',
+				'url_hash' => 'sha1',
 				'shared_secret' => 'iloveowncloud',
 				'sync_token' => '0'
 			]
@@ -47,6 +48,7 @@ class SyncFederationAddressbooksTest extends \Test\TestCase {
 		willReturn([
 			[
 				'url' => 'https://cloud.drop.box',
+				'url_hash' => 'sha1',
 				'shared_secret' => 'iloveowncloud',
 				'sync_token' => '0'
 			]