EBCC: Enclave-Backed Confidential Containers via OCI-Compatible Runtime Integration

TL;DR

EBCC introduces an OCI-compatible runtime architecture that manages composite confidential workloads across various TEEs, maintaining standard lifecycle operations while ensuring security and performance.

Contribution

It presents a novel OCI-compatible runtime design that unifies confidential container management across different TEE architectures, preserving lifecycle operations and enhancing manageability.

Findings

EBCC adds latency mainly due to lifecycle mediation and artifact management.

It maintains a concentrated footprint on host-side management state.

Cross-TEE case studies demonstrate flexible TEE integration.

Abstract

Container runtimes provide a stable operational interface for deploying, monitoring, and controlling modern workloads, while trusted execution environments (TEEs) provide hardware-enforced isolation for sensitive computation. Existing confidential-container systems often rely on VM-backed deployment stacks or TEE-specific execution substrates, which can separate confidential execution from the conventional OCI runtime lifecycle. This paper presents EBCC (Enclave-Backed Confidential Containers), an OCI-compatible runtime architecture for managing composite confidential-computing workloads. EBCC treats the REE-side anchor and TEE-side confidential stages as a single containerized confidential-computing composite, preserves standard OCI lifecycle operations, and keeps TEE-specific execution behind a backend adapter. It also maintains persistent per-instance state and per-stage artifacts for request handling, response generation, logging, and evidence binding. We implement EBCC on a Keystone backend and evaluate its correctness, performance, footprint, and concurrent execution behavior. The results show that EBCC introduces additional latency over native Keystone execution, mainly due to lifecycle mediation, request validation, EID allocation, backend dispatch, and artifact persistence, while keeping the added footprint concentrated on host-side management state. Cross-TEE case studies on SGX, TDX, and OP-TEE show that the same lifecycle and stage abstraction can be mapped to enclave-style, VM-style, and embedded-style TEEs. These results indicate that EBCC can make TEE-backed execution manageable through an OCI-style lifecycle without materially enlarging the protected-side TCB.