diff --git a/lib/Db/BoardMapper.php b/lib/Db/BoardMapper.php
index 9c734ac46e..d9d7d2c4b8 100644
--- a/lib/Db/BoardMapper.php
+++ b/lib/Db/BoardMapper.php
@@ -145,6 +145,22 @@ public function findByExternalId(int $externalId): array {
 		return $this->findEntities($qb);
 	}
 
+	/**
+	 * Used by ISignedCloudFederationProvider to resolve a board from a share token.
+	 *
+	 * @param string $shareToken
+	 * @return Board
+	 * @throws DoesNotExistException
+	 * @throws \OCP\AppFramework\Db\MultipleObjectsReturnedException
+	 */
+	public function findByShareToken(string $shareToken): Board {
+		$qb = $this->db->getQueryBuilder();
+		$qb->select('*')
+			->from('deck_boards')
+			->where($qb->expr()->eq('share_token', $qb->createNamedParameter($shareToken, IQueryBuilder::PARAM_STR)));
+		return $this->findEntity($qb);
+	}
+
 	public function findAllForUser(string $userId, ?int $since = null, bool $includeArchived = true, ?int $before = null,
 		?string $term = null): array {
 		$useCache = ($since === -1 && $includeArchived === true && $before === null && $term === null);
diff --git a/lib/Federation/DeckFederationProvider.php b/lib/Federation/DeckFederationProvider.php
index d6e37486c5..558b0d38cb 100644
--- a/lib/Federation/DeckFederationProvider.php
+++ b/lib/Federation/DeckFederationProvider.php
@@ -14,13 +14,15 @@
 use OCA\Deck\Db\BoardMapper;
 use OCA\Deck\Db\ChangeHelper;
 use OCA\Deck\Service\ConfigService;
+use OCP\AppFramework\Db\DoesNotExistException;
+use OCP\AppFramework\Db\MultipleObjectsReturnedException;
 use OCP\Common\Exception\NotFoundException;
-use OCP\Federation\ICloudFederationProvider;
 use OCP\Federation\ICloudFederationShare;
 use OCP\Federation\ICloudIdManager;
+use OCP\Federation\ISignedCloudFederationProvider;
 use OCP\Notification\IManager as INotificationManager;
 
-class DeckFederationProvider implements ICloudFederationProvider {
+class DeckFederationProvider implements ISignedCloudFederationProvider {
 	public const PROVIDER_ID = 'deck';
 
 	public function __construct(
@@ -106,4 +108,13 @@ public function notificationReceived($notificationType, $providerId, $notificati
 	public function getSupportedShareTypes(): array {
 		return ['user'];
 	}
+
+	#[\Override]
+	public function getFederationIdFromSharedSecret(#[\SensitiveParameter] string $sharedSecret, array $payload): string {
+		try {
+			return $this->boardMapper->findByShareToken($sharedSecret)->getOwner();
+		} catch (DoesNotExistException|MultipleObjectsReturnedException) {
+			return '';
+		}
+	}
 }