Acronyms and key terms used throughout this book, listed alphabetically.
| Acronym / Term | Expansion | Brief Definition |
|---|---|---|
| AA | Attestation Agent | Component inside the CoCo CVM that handles the attestation process on behalf of the workload |
| ARK | AMD Root Key | Top-level key in AMD’s certificate chain, used to sign the AMD SEV Key (ASK) |
| AS | Attestation Service | Trustee component that verifies attestation evidence against reference values |
| ASK | AMD SEV Key | Intermediate key in AMD’s certificate chain, signed by the ARK and used to sign the VCEK |
| BYOM | Bring Your Own Machine | Deployment model where the user supplies their own (remote) machine as the CVM host |
| CAA | Cloud API Adaptor | CoCo component that provisions peer-pod CVMs via cloud provider APIs |
| CCA | Confidential Compute Architecture | Arm’s VM-based TEE architecture (Armv9), introducing Realms managed by the Realm Management Monitor |
| CDH | Confidential Data Hub | CoCo component inside the CVM that acts as a proxy for secret retrieval |
| CNI | Container Network Interface | Standard interface for Kubernetes pod networking plugins (e.g. Flannel, Calico) |
| CRI | Container Runtime Interface | Kubernetes API that kubelet uses to talk to container runtimes such as containerd and CRI-O |
| CoCo | Confidential Containers | CNCF project for running Kubernetes pods inside CVMs using Kata Containers |
| CoVE | Confidential VM Extensions | RISC-V specification for VM-based TEEs |
| CVM | Confidential Virtual Machine | A virtual machine running inside a TEE, with hardware-encrypted memory |
| CDI | Container Device Interface | Standard for exposing hardware devices to containers |
| DICE | Device Identifier Composition Engine | Hardware RoT standard for deriving layered identity keys at each boot stage |
| DMA | Direct Memory Access | Hardware mechanism allowing devices to access system memory without CPU involvement; a source of side-channel risk |
| FHE | Fully Homomorphic Encryption | Cryptographic technique for computing directly on encrypted data without decrypting it |
| GHCR | GitHub Container Registry | GitHub’s OCI-compatible container and artifact registry (ghcr.io) |
| GRUB | Grand Unified Bootloader | Common Linux bootloader responsible for loading the kernel |
| IETF | Internet Engineering Task Force | Standards body that publishes internet and security protocol specifications (RFCs) |
| initdata | Initialization Data | Mechanism for passing measured configuration (KBS URL, agent policy) into a CoCo CVM at boot; its hash is bound into the attestation evidence |
| ITA | Intel Trust Authority | Intel’s hosted attestation verification service for TDX and SGX |
| KBS | Key Broker Service | Trustee component that releases secrets (keys, certificates) only after successful attestation |
| KDS | Key Distribution Service | AMD’s public service for distributing VCEK certificates by chip ID and TCB version |
| KVM | Kernel-based Virtual Machine | Linux kernel hypervisor module used by QEMU to run VMs |
| LLC | Last-Level Cache | The largest shared CPU cache (typically L3); a surface for cache side-channel attacks |
| LUKS | Linux Unified Key Setup | Standard disk encryption specification on Linux, used to protect ephemeral CVM storage |
| MAA | Microsoft Azure Attestation | Azure’s attestation verification service for SEV-SNP, TDX, and SGX |
| MPC | Secure Multi-Party Computation | Cryptographic protocols that let multiple parties jointly compute a function without revealing their private inputs |
| MRTD | Measurement Register for Trust Domain | Intel TDX build-time measurement register covering the initial TD contents (e.g. the TDVF firmware) |
| NRAS | NVIDIA Remote Attestation Service | NVIDIA’s hosted service for verifying GPU attestation evidence |
| NSG | Network Security Group | Cloud firewall construct (e.g. Azure) controlling inbound/outbound traffic to VMs |
| Nydus | — | containerd snapshotter (nydus-snapshotter) used by CoCo to delegate container image pulling to the guest CVM |
| OCI | Open Container Initiative | Standards body defining container image and runtime specifications |
| OPA | Open Policy Agent | General-purpose policy engine; used in CoCo to enforce initdata policies |
| ORAS | OCI Registry As Storage | Tool for pushing and pulling arbitrary artifacts (binaries, configs) from OCI registries |
| OVMF | Open Virtual Machine Firmware | Open-source UEFI firmware used as the guest firmware in QEMU/KVM VMs |
| PCE | Provisioning Certification Enclave | Intel SGX enclave that certifies the Quoting Enclave’s attestation key |
| PCK | Provisioning Certification Key | Intel platform-specific key used to sign TDX/SGX quote collateral |
| PCCS | Provisioning Certificate Caching Service | Local caching proxy for Intel PCS certificates, reducing latency in production deployments |
| PCR | Platform Configuration Register | Tamper-evident register inside a TPM that accumulates boot measurements via hash extension |
| PCS | Provisioning Certification Service | Intel’s public service for distributing PCK certificates for TDX and SGX platforms |
| Peer pods | — | CoCo deployment model where the pod CVM runs on a remote hypervisor (provisioned via cloud APIs by CAA) instead of nested on the worker node |
| PSP | Platform Security Processor | Alternative name for AMD’s dedicated security processor (also called ASP) |
| QE | Quoting Enclave | Intel SGX/TDX enclave that signs attestation quotes using a platform attestation key |
| QEMU | Quick EMUlator | Open-source machine emulator and virtualizer; used with KVM to run CVMs |
| RAG | Retrieval-Augmented Generation | LLM technique that grounds responses by retrieving relevant documents at query time |
| RATS | Remote ATtestation procedureS | IETF framework (RFC 9334) defining roles and flows for remote attestation |
| RFC | Request for Comments | IETF standards document; RFC 9334 defines the RATS attestation framework |
| RoT | Root of Trust | Foundational hardware component (e.g. AMD SP, TPM) whose integrity is assumed and not derived |
| RTMR | Runtime Extendable Measurement Register | Intel TDX equivalent of TPM PCRs; accumulates measurements during and after boot |
| RVPS | Reference Value Provider Service | Trustee component that stores and serves “golden” reference measurements for comparison |
| SEAM | Secure Arbitration Mode | New Intel CPU operation mode introduced by TDX to host and manage Trust Domains |
| SEV | Secure Encrypted Virtualization | AMD technology for encrypting VM memory to protect it from the hypervisor |
| SEV-SNP | Secure Encrypted Virtualization — Secure Nested Paging | AMD’s extension to SEV adding integrity protection and a hardware attestation report |
| SFTP | Secure File Transfer Protocol | SSH-based protocol for secure file transfer between hosts |
| SGX | Software Guard Extensions | Intel’s process-based TEE technology for running isolated enclaves within an application |
| SNP | Secure Nested Paging | The page-integrity component of AMD SEV-SNP that prevents hypervisor memory tampering |
| SPIFFE | Secure Production Identity Framework for Everyone | CNCF standard for workload identity in distributed systems |
| SPIRE | SPIFFE Runtime Environment | Reference implementation of the SPIFFE standard |
| SVSM | Secure VM Service Module | Software component that runs inside a TEE and provides hypervisor-like services (e.g. vTPM) without trusting the hypervisor |
| TCB | Trusted Computing Base | The minimal set of hardware, firmware, and software components that must be trusted for security to hold |
| TCG | Trusted Computing Group | Industry consortium that defines TPM and related trusted computing standards |
| TDISP | TEE Device Interface Security Protocol | PCIe standard for attesting a device and admitting it into a VM-based TEE for direct DMA (trusted I/O) |
| TDVF | TDX Virtual Firmware | OVMF-based guest firmware for Intel TDX Trust Domains |
| TDX | Trust Domain Extensions | Intel’s VM-based TEE technology that protects entire VMs (Trust Domains) from the hypervisor |
| TEE | Trusted Execution Environment | Hardware-enforced isolated region of a processor protecting code and data from privileged software |
| TPM | Trusted Platform Module | Hardware chip (or firmware equivalent) for secure key storage, measurement, and attestation |
| UEFI | Unified Extensible Firmware Interface | Modern PC firmware standard that replaced BIOS; provides Secure Boot capabilities |
| UKI | Unified Kernel Image | A single EFI binary bundling the kernel, initramfs, and kernel command line for measured boot |
| VCEK | Versioned Chip Endorsement Key | AMD per-chip, per-firmware key used to sign SNP attestation reports |
| vTPM | Virtual Trusted Platform Module | Software emulation of a TPM 2.0 chip, provided to a guest VM by the hypervisor or SVSM |