ssize_t cross_cell_write(struct file *filp, const char __user *buf,
			  size_t count, loff_t *f_pos){
  char message[50] = "hello";
  char answer[50] = "";
  int size = 0;
  int retval = 0;

  retval = okl4_message_call(decrypt_cell,
			     message,
			     strlen(message)+1,
			     answer,
			     sizeof(answer),
			     &size);
  if(!retval){
    printk(KERN_WARNING "sending error\n");
  }else{
    printk(KERN_DEBUG "answer: %s\n", answer);
  }
}