Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

A Confidential Computing Transparency Framework for a Comprehensive Trust Chain

Ceren Kocaoğullar, Tina Marjanov, Ivan Petrov, Ben Laurie, Al Cutter, Christoph Kern, Alice Hutchings, Alastair R. Beresford

TL;DR

This paper addresses the trust gap in Confidential Computing by proposing a three-level transparency framework for TEEs and end-to-end systems. It integrates end-to-end provenance, reproducible builds, and verifiable transparency logs with accountable reviewers to strengthen the trust chain beyond attestation. A large user study shows that greater transparency increases user comfort and willingness to share data, while also revealing persistent misconceptions that can be mitigated with clearer communication. The framework has practical implications for industry adoption, standardization, and future research in hardware and software transparency practices.

Abstract

Confidential Computing enhances privacy of data in-use through hardware-based Trusted Execution Environments (TEEs) that use attestation to verify their integrity, authenticity, and certain runtime properties, along with those of the binaries they execute. However, TEEs require user trust, as attestation alone cannot guarantee the absence of vulnerabilities or backdoors. Enhanced transparency can mitigate the reliance on naive trust. Some organisations currently employ various transparency measures, including open-source firmware, publishing technical documentation, or undergoing external audits, but these require investments with unclear returns. This may discourage the adoption of transparency, leaving users with limited visibility into system privacy measures. Additionally, the lack of standardisation complicates meaningful comparisons between implementations. To address these challenges, we propose a three-level conceptual framework providing organisations with a practical pathway to incrementally improve Confidential Computing transparency. To evaluate whether our transparency framework contributes to an increase in end-user trust, we conducted an empirical study with over 800 non-expert participants. The results indicate that greater transparency improves user comfort, with participants willing to share various types of personal data across different levels of transparency. The study also reveals misconceptions about transparency, highlighting the need for clear communication and user education.

A Confidential Computing Transparency Framework for a Comprehensive Trust Chain

TL;DR

This paper addresses the trust gap in Confidential Computing by proposing a three-level transparency framework for TEEs and end-to-end systems. It integrates end-to-end provenance, reproducible builds, and verifiable transparency logs with accountable reviewers to strengthen the trust chain beyond attestation. A large user study shows that greater transparency increases user comfort and willingness to share data, while also revealing persistent misconceptions that can be mitigated with clearer communication. The framework has practical implications for industry adoption, standardization, and future research in hardware and software transparency practices.

Abstract

Confidential Computing enhances privacy of data in-use through hardware-based Trusted Execution Environments (TEEs) that use attestation to verify their integrity, authenticity, and certain runtime properties, along with those of the binaries they execute. However, TEEs require user trust, as attestation alone cannot guarantee the absence of vulnerabilities or backdoors. Enhanced transparency can mitigate the reliance on naive trust. Some organisations currently employ various transparency measures, including open-source firmware, publishing technical documentation, or undergoing external audits, but these require investments with unclear returns. This may discourage the adoption of transparency, leaving users with limited visibility into system privacy measures. Additionally, the lack of standardisation complicates meaningful comparisons between implementations. To address these challenges, we propose a three-level conceptual framework providing organisations with a practical pathway to incrementally improve Confidential Computing transparency. To evaluate whether our transparency framework contributes to an increase in end-user trust, we conducted an empirical study with over 800 non-expert participants. The results indicate that greater transparency improves user comfort, with participants willing to share various types of personal data across different levels of transparency. The study also reveals misconceptions about transparency, highlighting the need for clear communication and user education.
Paper Structure (29 sections, 4 figures, 4 tables)

This paper contains 29 sections, 4 figures, 4 tables.

Table of Contents

  1. Introduction
  2. Defining transparency
  3. Necessity of transparency
  4. Scope of transparency
  5. Agents of transparency
  6. Beneficiaries of transparency
  7. Confidential Computing Transparency
  8. Level 1 (L1)
  9. Level 2 (L2)
  10. Level 3 (L3)
  11. Revocation
  12. Additional considerations
  13. Monitoring transparency logs
  14. Inclusion proofs
  15. Trusted builders
  16. ...and 14 more sections

Figures (4)

  • Figure 1: Graph showing all certifier trait combinations, with each quadrant including examples from the three reviewer categories where applicable. An asterisk (*) indicates that researchers may have varying motivations and methods, such as (II) those funded by code owners, (III) volunteer researchers in community efforts, and (IV) those focused on finding vulnerabilities and publishing papers.
  • Figure 2: A depiction of the three transparency levels in our framework, showing the agents and trust-building blocks needed to achieve them. Each level builds on the previous one by adding more trust-building elements.
  • Figure 3: Violin plots of participants' comfort levels, aggregated over all data types.
  • Figure 4: Boxplots of participants' comfort levels.

Theorems & Definitions (1)

  • Definition 3.1: Transparency