Improving the Security of Containerized Workloads using Transparency and Traceability Services
TL;DR
This paper presents an architecture for verifiable container image distribution that addresses key-management challenges and enables policy-enforced admission-time verification, and implements a proof-of-concept integrated with GitHub Actions and GitLab Runners that mitigates common supply-chain attacks under a realistic threat model.
Abstract
Containerized workloads are commonly built via CI/CD pipelines, stored in registries, and executed across heterogeneous infrastructures, including cloud and edge environments. A single compromised build step or credential can turn routine automation into large-scale distribution of malicious artifacts, motivating integrity, transparency, and enforceable deployment-time checks. In this paper, we present an architecture for verifiable container image distribution that addresses key-management challenges and enables policy-enforced admission-time verification. A transparency service generates one-time signing keys bound to authenticated identities, records signing events in an append-only transparency registry, and returns cryptographically verifiable proofs of inclusion. These proofs and identity attributes are attached to image metadata and evaluated by policy-as-code at admission time, so only compliant artifacts are deployed. We implement a proof-of-concept integrated with GitHub Actions and GitLab Runners and evaluate how the resulting pipeline mitigates common supply-chain attacks under a realistic threat model.