Confidential Serverless Computing

2025-04-30

AI Summary

To address the challenge of securely executing sensitive data in serverless computing environments hosted on untrusted cloud infrastructure, this paper proposes Hacher—a novel system featuring a nested confidential execution mechanism and a decoupled, lightweight library OS (LibOS) to construct a minimal trusted execution unit (trustlet). It further introduces a data-centric LibOS I/O architecture that simultaneously ensures confidentiality and improves resource efficiency. Built upon confidential virtual machines (CVMs), Hacher significantly reduces the trusted computing base (TCB) by 4.3×. Evaluation shows end-to-end latency reductions of 15–93%, up to 907× higher function deployment density, 27× lower inter-function communication overhead, and 16.7–30.2× reduced latency for function chains—demonstrating substantial improvements in both security and performance for confidential serverless computing.

Technology Category

• Machine Learning: Hardware-aware ML
• Computer Vision: Large Vision Models
• Natural Language Processing: Safety and Robustness

Application Category

• Security and Privacy: Data transparency and provenance
• Responsible Web: Data and user privacy-enhancing technologies for the Web
• Systems and Infrastructure for Web, Mobile and WoT: Experiences and lessons learnt from Web-based algorithms and system deployments

Abstract

Although serverless computing offers compelling cost and deployment simplicity advantages, a significant challenge remains in securely managing sensitive data as it flows through the network of ephemeral function executions in serverless computing environments within untrusted clouds. While Confidential Virtual Machines (CVMs) offer a promising secure execution environment, their integration with serverless architectures currently faces fundamental limitations in key areas: security, performance, and resource efficiency. We present Hacher, a confidential computing system for secure serverless deployments to overcome these limitations. By employing nested confidential execution and a decoupled guest OS within CVMs, Hacher runs each function in a minimal"trustlet", significantly improving security through a reduced Trusted Computing Base (TCB). Furthermore, by leveraging a data-centric I/O architecture built upon a lightweight LibOS, Hacher optimizes network communication to address performance and resource efficiency challenges. Our evaluation shows that compared to CVM-based deployments, Hacher has 4.3x smaller TCB, improves end-to-end latency (15-93%), achieves higher function density (up to 907x), and reduces inter-function communication (up to 27x) and function chaining latency (16.7-30.2x); thus, Hacher offers a practical system for confidential serverless computing.

Problem

• Securing sensitive data in untrusted serverless cloud environments
• Overcoming security, performance, resource limits in confidential serverless computing
• Reducing TCB and optimizing I/O for confidential serverless deployments

Innovation

• Nested confidential execution in CVMs
• Decoupled guest OS for minimal trustlets
• Data-centric I/O with lightweight LibOS