A Confidential Computing Transparency Framework for a Comprehensive Trust Chain

TL;DR

This paper proposes a three-level transparency framework for Confidential Computing to enhance trust, supported by an empirical study showing increased user comfort with greater transparency, despite existing misconceptions.

Contribution

It introduces a practical, incremental transparency framework for Confidential Computing and empirically evaluates its impact on user trust and understanding.

Findings

Greater transparency increases user comfort and willingness to share data.

Misconceptions about transparency highlight the need for better communication.

The framework provides a standardized approach to improve trust in Confidential Computing.

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.