diff --git a/composer.json b/composer.json
index a403b67..1099572 100644
--- a/composer.json
+++ b/composer.json
@@ -15,7 +15,7 @@
         }
     ],
     "require": {
-        "pdsinterop/solid-auth": "v0.14.1",
+        "pdsinterop/solid-auth": "v0.14.2",
         "pdsinterop/solid-crud": "v0.8.4",
         "phpmailer/phpmailer": "^6.10",
         "sweetrdf/easyrdf": "~1.15.0",
diff --git a/init.php b/init.php
index 94c1b72..21e739a 100644
--- a/init.php
+++ b/init.php
@@ -24,7 +24,7 @@ function initDatabase()
 		clientData TEXT NOT NULL
 		)',
 		'CREATE TABLE IF NOT EXISTS allowedClients (
-		userId VARCHAR(255) NOT NULL PRIMARY KEY,
+		userId VARCHAR(255) NOT NULL,
 		clientId VARCHAR(255) NOT NULL
 		)',
 		'CREATE TABLE IF NOT EXISTS userStorage (
diff --git a/lib/Routes/SolidIdp.php b/lib/Routes/SolidIdp.php
index 9e628bc..6effd9d 100644
--- a/lib/Routes/SolidIdp.php
+++ b/lib/Routes/SolidIdp.php
@@ -128,12 +128,17 @@ public static function respondToRegister()
 
 
 		$generatedClientId = bin2hex(random_bytes(16)); // 32 chars for the client Id
-		$generatedClientSecret = bin2hex(random_bytes(32)); // and 64 chars for the client secret
 
 		$clientData['client_id_issued_at'] = time();
 		$clientData['client_id'] = $generatedClientId;
-		$clientData['client_secret'] = $generatedClientSecret;
 		$clientData['origin'] = $origin;
+		if (
+			(!isset($clientData['token_endpoint_auth_method'])) || // if not set, assume we have to add a client secret;
+			($clientData['token_endpoint_auth_method'] !== 'none')
+		) { // generate and use secret if we have token endpoint authentication
+			$generatedClientSecret = bin2hex(random_bytes(32)); // and 64 chars for the client secret
+			$clientData['client_secret'] = $generatedClientSecret;
+		}
 		ClientRegistration::saveClientRegistration($clientData);
 
 		$client = ClientRegistration::getRegistration($generatedClientId);
@@ -141,16 +146,20 @@ public static function respondToRegister()
 		$responseData = array(
 			'redirect_uris' => $client['redirect_uris'],
 			'client_id' => $client['client_id'],
-			'client_secret' => $client['client_secret'],
 			'response_types' => array('code'),
 			'grant_types' => array('authorization_code', 'refresh_token'),
 			'application_type' => $client['application_type'] ?? 'web',
 			'client_name' => $client['client_name'] ?? $client['client_id'],
 			'id_token_signed_response_alg' => 'RS256',
-			'token_endpoint_auth_method' => 'client_secret_basic',
-			'client_id_issued_at' => $client['client_id_issued_at'],
-			'client_secret_expires_at' => 0
+			'client_id_issued_at' => $client['client_id_issued_at']
 		);
+		if (isset($client['client_secret'])) {
+			$responseData['client_secret'] = $client['client_secret'];
+			$responseData['token_endpoint_auth_method'] = 'client_secret_basic';
+			$responseData['client_secret_expires_at'] = 0;
+		} else {
+			$responseData['token_endpoint_auth_method'] = 'none'; // No client secret means we can't authenticate on the token endpoint;
+		}
 		header("HTTP/1.1 201 Created");
 		header("Content-type: application/json");
 		echo json_encode($responseData, JSON_PRETTY_PRINT | JSON_THROW_ON_ERROR);
diff --git a/lib/Server.php b/lib/Server.php
index 204f5ab..98a1ed7 100644
--- a/lib/Server.php
+++ b/lib/Server.php
@@ -73,6 +73,20 @@ public static function getConfigClient()
 			$registeredClient = ClientRegistration::getRegistration($clientId);
 		}
 		if (isset($registeredClient)) {
+			/*
+				If the token_endpoint_auth_method is 'none',
+				this means we are dealing with a public
+				client that is not able to securely store
+				the client secret.  In that case, we remove
+				the client_secret so we treat the client as
+				a public client
+			*/
+			if (
+				isset($registeredClient['token_endpoint_auth_method']) &&
+				($registeredClient['token_endpoint_auth_method'] === "none")
+			) {
+				unset($registeredClient['client_secret']);
+			}
 			return new ConfigClient(
 				$clientId,
 				$registeredClient['client_secret'] ?? '',
diff --git a/upgrade/0.4.1/upgrade.functions.php b/upgrade/0.4.1/upgrade.functions.php
new file mode 100644
index 0000000..f2d76d5
--- /dev/null
+++ b/upgrade/0.4.1/upgrade.functions.php
@@ -0,0 +1,24 @@
+<?php
+
+function upgradeDatabase()
+{
+	$statements = [
+		'BEGIN TRANSACTION',
+		'CREATE TABLE allowedClients_new (userId VARCHAR(255) NOT NULL, clientId VARCHAR(255) NOT NULL)',
+		'INSERT INTO allowedClients_new (userId, clientId) SELECT userId, clientId FROM allowedClients',
+		'DROP TABLE allowedClients',
+		'ALTER TABLE allowedClients_new RENAME TO allowedClients',
+		'COMMIT'
+	];
+
+	try {
+		$pdo = new \PDO("sqlite:" . DBPATH);
+
+		// create tables
+		foreach ($statements as $statement) {
+			$pdo->exec($statement);
+		}
+	} catch (\PDOException $e) {
+		echo $e->getMessage();
+	}
+}
diff --git a/upgrade/0.4.1/upgrade.php b/upgrade/0.4.1/upgrade.php
new file mode 100644
index 0000000..9f09478
--- /dev/null
+++ b/upgrade/0.4.1/upgrade.php
@@ -0,0 +1,9 @@
+<?php
+
+require_once(__DIR__ . "/../../config.php");
+require_once(__DIR__ . "/../../vendor/autoload.php");
+require_once(__DIR__ . "/upgrade.functions.php");
+
+use Pdsinterop\PhpSolid\Server;
+
+upgradeDatabase();