# LightBox: Full-stack Protected Stateful Middlebox at Lightning Speed

## TL;DR

LightBox is a system that enables secure, high-speed, stateful processing of off-site middleboxes using Intel SGX, addressing security and performance challenges in handling sensitive network traffic.

## Contribution

It introduces a novel full-stack protected middlebox architecture with state management and metadata protection, achieving near-native speed at 10Gbps using commodity hardware.

## Key findings

- Achieves 10Gbps packet I/O with security protections.
- Supports stateful processing of hundreds of thousands of flows.
- Operates at near-native speed in case studies.

## Abstract

Running off-site software middleboxes at third-party service providers has been a popular practice. However, routing large volumes of raw traffic, which may carry sensitive information, to a remote site for processing raises severe security concerns. Prior solutions often abstract away important factors pertinent to real-world deployment. In particular, they overlook the significance of metadata protection and stateful processing. Unprotected traffic metadata like low-level headers, size and count, can be exploited to learn supposedly encrypted application contents. Meanwhile, tracking the states of 100,000s of flows concurrently is often indispensable in production-level middleboxes deployed at real networks. We present LightBox, the first system that can drive off-site middleboxes at near-native speed with stateful processing and the most comprehensive protection to date. Built upon commodity trusted hardware, Intel SGX, LightBox is the product of our systematic investigation of how to overcome the inherent limitations of secure enclaves using domain knowledge and customization. First, we introduce an elegant virtual network interface that allows convenient access to fully protected packets at line rate without leaving the enclave, as if from the trusted source network. Second, we provide complete flow state management for efficient stateful processing, by tailoring a set of data structures and algorithms optimized for the highly constrained enclave space. Extensive evaluations demonstrate that LightBox, with all security benefits, can achieve 10Gbps packet I/O, and that with case studies on three stateful middleboxes, it can operate at near-native speed.