public function set($name, $ttl = 3600) {
    $rand = $this->psl['crypt/rand'];
    $cache = $this->psl['cache'];

    $token = $rand->str(32, $this->_charset);
    /* Save the token to the cahce. */
    $cache->cacheSet('token-'.$name, $token, $ttl);
    return $token;
  }