private String generateKid(JsonValue jwkSet, String algorithm) {

    final JwsAlgorithm jwsAlgorithm = JwsAlgorithm.valueOf(algorithm);
    if (JwsAlgorithmType.RSA.equals(jwsAlgorithm.getAlgorithmType())) {
      JsonValue jwks = jwkSet.get(OAuth2Constants.JWTTokenParams.KEYS);
      if (!jwks.isNull() && !jwks.asList().isEmpty()) {
        return jwks.get(0).get(OAuth2Constants.JWTTokenParams.KEY_ID).asString();
      }
    }

    return null;
  }