diff --git a/build/build.xml b/build/build.xml
index 6d5b652b0a..b47b5f6eff 100644
--- a/build/build.xml
+++ b/build/build.xml
@@ -355,6 +355,13 @@
 		<delete file="${dir}/vendor/lusitanian/oauth/phpunit.xml.dist" />
 		<delete file="${dir}/vendor/lusitanian/oauth/README.md" />
 
+		<delete dir="${dir}/vendor/paragonie/random_compat/dist" />
+		<delete dir="${dir}/vendor/paragonie/random_compat/other" />
+		<delete file="${dir}/vendor/paragonie/random_compat/CHANGELOG.md" />
+		<delete file="${dir}/vendor/paragonie/random_compat/ERRATA.md" />
+		<delete file="${dir}/vendor/paragonie/random_compat/README.md" />
+		<delete file="${dir}/vendor/paragonie/random_compat/SECURITY.md" />
+
 		<delete file="${dir}/vendor/patchwork/utf8/.travis.yml" />
 		<delete file="${dir}/vendor/patchwork/utf8/CHANGELOG.md" />
 		<delete file="${dir}/vendor/patchwork/utf8/phpunit.xml.dist" />
diff --git a/phpBB/composer.json b/phpBB/composer.json
index 88df2bfa3d..b0c9b57cb6 100644
--- a/phpBB/composer.json
+++ b/phpBB/composer.json
@@ -31,6 +31,7 @@
 		"guzzlehttp/guzzle": "~5.3",
 		"lusitanian/oauth": "^0.8.1",
 		"marc1706/fast-image-size": "1.1.*",
+		"paragonie/random_compat": "^1.2",
 		"patchwork/utf8": "1.1.*",
 		"s9e/text-formatter": "^0.4.2",
 		"symfony/config": "2.8.*",
diff --git a/phpBB/composer.lock b/phpBB/composer.lock
index 7cb6c160ce..d10c94a75f 100644
--- a/phpBB/composer.lock
+++ b/phpBB/composer.lock
@@ -4,8 +4,8 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file",
         "This file is @generated automatically"
     ],
-    "hash": "2de20b0ffe0ca05fb62a7c685a25ca79",
-    "content-hash": "6e427257e82c0d33fc94040d9685f516",
+    "hash": "9cbb41222e71eb86e0ef9118baafc691",
+    "content-hash": "03a990fa2d088c89afe4824d2d53e873",
     "packages": [
         {
             "name": "bantu/ini-get-wrapper",
@@ -401,6 +401,54 @@
             ],
             "time": "2015-08-21 11:40:30"
         },
+        {
+            "name": "paragonie/random_compat",
+            "version": "v1.2.0",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/paragonie/random_compat.git",
+                "reference": "b0e69d10852716b2ccbdff69c75c477637220790"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/paragonie/random_compat/zipball/b0e69d10852716b2ccbdff69c75c477637220790",
+                "reference": "b0e69d10852716b2ccbdff69c75c477637220790",
+                "shasum": ""
+            },
+            "require": {
+                "php": ">=5.2.0"
+            },
+            "require-dev": {
+                "phpunit/phpunit": "4.*|5.*"
+            },
+            "suggest": {
+                "ext-libsodium": "Provides a modern crypto API that can be used to generate random bytes."
+            },
+            "type": "library",
+            "autoload": {
+                "files": [
+                    "lib/random.php"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Paragon Initiative Enterprises",
+                    "email": "security@paragonie.com",
+                    "homepage": "https://paragonie.com"
+                }
+            ],
+            "description": "PHP 5.x polyfill for random_bytes() and random_int() from PHP 7",
+            "keywords": [
+                "csprng",
+                "pseudorandom",
+                "random"
+            ],
+            "time": "2016-02-06 03:52:05"
+        },
         {
             "name": "patchwork/utf8",
             "version": "v1.1.31",
diff --git a/phpBB/includes/functions.php b/phpBB/includes/functions.php
index 54ff51dda5..5125a601d6 100644
--- a/phpBB/includes/functions.php
+++ b/phpBB/includes/functions.php
@@ -93,25 +93,10 @@ function gen_rand_string_friendly($num_chars = 8)
 
 /**
 * Return unique id
-* @param string $extra additional entropy
 */
-function unique_id($extra = 'c')
+function unique_id()
 {
-	static $dss_seeded = false;
-	global $config;
-
-	$val = $config['rand_seed'] . microtime();
-	$val = md5($val);
-	$config['rand_seed'] = md5($config['rand_seed'] . $val . $extra);
-
-	if ($dss_seeded !== true && ($config['rand_seed_last_update'] < time() - rand(1,10)))
-	{
-		$config->set('rand_seed_last_update', time(), false);
-		$config->set('rand_seed', $config['rand_seed'], false);
-		$dss_seeded = true;
-	}
-
-	return substr($val, 4, 16);
+	return bin2hex(random_bytes(6));
 }
 
 /**