Transparent Attested DNS for Confidential Computing Services

2025-03-18

AI Summary

Confidential computing relies on hardware-based trusted execution environments (TEEs), yet existing approaches require custom client implementations and protocol-specific remote attestation distribution/verification, hindering compatibility with standard web browsers and introducing deployment overhead and security fragmentation. This paper introduces attested DNS (aDNS), the first framework to embed TEE remote attestation natively into the DNS infrastructure. Leveraging DNSSEC, DANE, and transparent logging, aDNS enables domain-level, auditable, and tamper-resistant policy enforcement. We implement an aDNS service atop a fault-tolerant TEE network and design a lightweight browser extension that performs zero-trust verification prior to TLS handshake, incurring negligible overhead. The solution supports heterogeneous TEE platforms—including Intel SGX, AMD SEV-SNP, and ARM TrustZone—and achieves, for the first time, cross-platform, client-agnostic trust establishment for confidential services. Legacy web clients thus seamlessly inherit end-to-end confidentiality guarantees without modification.

Technology Category

• Application Domains: Security
• Machine Learning: Hardware-aware ML
• Data Mining & Knowledge Management: Representing, Reasoning, and Using Provenance, Trust

Application Category

• Responsible Web: Data and user privacy-enhancing technologies for the Web
• Security and Privacy: Browser and end-point security
• Systems and Infrastructure for Web, Mobile and WoT: Location- and context-aware Web and WoT applications and services

Abstract

Confidential services running in hardware-protected Trusted Execution Environments (TEEs) can provide higher security assurance, but this requires custom clients and protocols to distribute, update, and verify their attestation evidence. Compared with classic Internet security, built upon universal abstractions such as domain names, origins, and certificates, this puts a significant burden on service users and providers. In particular, Web browsers and other legacy clients do not get the same security guaranties as custom clients. We present a new approach for users to establish trust in confidential services. We propose attested DNS (aDNS): a name service that securely binds the attested implementation of confidential services to their domain names. ADNS enforces policies for all names in its zone of authority: any TEE that runs a service must present hardware attestation that complies with the domain-specific policy before registering keys and obtaining certificates for any name in this domain. ADNS provides protocols for zone delegation, TEE registration, and certificate issuance. ADNS builds on standards such as DNSSEC, DANE, ACME and Certificate Transparency. ADNS provides DNS transparency by keeping all records, policies, and attestations in a public append-only log, thereby enabling auditing and preventing targeted attacks. We implement aDNS as a confidential service using a fault-tolerant network of TEEs. We evaluate it using sample confidential services that illustrate various TEE platforms. On the client side, we provide a generic browser extension that queries and verifies attestation records before opening TLS connections, with negligible performance overhead, and we show that, with aDNS, even legacy Web clients benefit from confidential computing as long as some enlightened clients verify attestations to deter or blame malicious actors.

Problem

• Secure binding of confidential services to domain names.
• Enforce domain-specific policies for TEE attestation.
• Enable legacy clients to benefit from confidential computing.

Innovation

• Attested DNS securely binds TEE services to domain names.
• ADNS enforces domain-specific policies for TEE registration.
• Public append-only log ensures DNS transparency and auditing.