## Feature Comparison Chart: SGX, TrustZone, SEV, and RISC-V ### Overview The image is a feature comparison chart evaluating different secure execution environments (SEEs) across several features. The chart compares SGX, TrustZone, SEV, and RISC-V implementations, indicating whether each feature is supported (filled circle) or not supported (empty circle) by each SEE. ### Components/Axes * **Columns (Secure Execution Environments):** * SGX: Client SGX, Scalable SGX * TrustZone: TrustZone-A, TrustZone-M * SEV: Vanilla, SEV-ES, SEV-SNP, Keystone * RISC-V: Sanctum, TIMBER-V, LIRA-V * **Rows (Features):** * Integrity * Freshness * Encryption * Unlimited domains * Open source * Local attestation * Remote attestation * API for attestation * Mutual attestation * User-mode support * Industrial TEE * Isolation and attestation granularity * System support for isolation ### Detailed Analysis or ### Content Details **SGX** * **Client SGX:** * Integrity: Supported (filled circle) * Freshness: Supported (filled circle) * Encryption: Supported (filled circle) * Unlimited domains: Supported (filled circle) * Open source: Not supported (empty circle) * Local attestation: Supported (filled circle) * Remote attestation: Supported (filled circle) * API for attestation: Supported (filled circle) * Mutual attestation: Not supported (empty circle) * User-mode support: Supported (filled circle) * Industrial TEE: Not supported (empty circle) * Isolation and attestation granularity: Intra-address space * System support for isolation: µcode + XuCode * **Scalable SGX:** * Integrity: Not supported (empty circle) * Freshness: Partially supported (half-filled circle) * Encryption: Not supported (empty circle) * Unlimited domains: Not supported (empty circle) * Open source: Partially supported (half-filled circle) * Local attestation: Supported (filled circle) * Remote attestation: Supported (filled circle) * API for attestation: Supported (filled circle) * Mutual attestation: Not supported (empty circle) * User-mode support: Supported (filled circle) * Industrial TEE: Not supported (empty circle) **TrustZone** * **TrustZone-A:** * Integrity: Not supported (empty circle) * Freshness: Not supported (empty circle) * Encryption: Not supported (empty circle) * Unlimited domains: Not supported (empty circle) * Open source: Not supported (empty circle) * Local attestation: Not supported (empty circle) * Remote attestation: Not supported (empty circle) * API for attestation: Not supported (empty circle) * Mutual attestation: Not supported (empty circle) * User-mode support: Supported (filled circle) * Industrial TEE: Not supported (empty circle) * Isolation and attestation granularity: Secure world * System support for isolation: SMC MPU * **TrustZone-M:** * All features except User-mode support are not supported (empty circle). * User-mode support: Supported (filled circle) **SEV** * **Vanilla:** * Integrity: Not supported (empty circle) * Freshness: Not supported (empty circle) * Encryption: Not supported (empty circle) * Unlimited domains: Partially supported (half-filled circle) * Open source: Not supported (empty circle) * Local attestation: Supported (filled circle) * Remote attestation: Supported (filled circle) * API for attestation: Supported (filled circle) * Mutual attestation: Not supported (empty circle) * User-mode support: Supported (filled circle) * Industrial TEE: Not supported (empty circle) * Isolation and attestation granularity: VM * System support for isolation: Firmware * **SEV-ES:** * Integrity: Supported (filled circle) * Freshness: Supported (filled circle) * Encryption: Supported (filled circle) * Unlimited domains: Supported (filled circle) * Open source: Supported (filled circle) * Local attestation: Supported (filled circle) * Remote attestation: Supported (filled circle) * API for attestation: Supported (filled circle) * Mutual attestation: Supported (filled circle) * User-mode support: Supported (filled circle) * Industrial TEE: Not supported (empty circle) * **SEV-SNP:** * Integrity: Supported (filled circle) * Freshness: Supported (filled circle) * Encryption: Supported (filled circle) * Unlimited domains: Supported (filled circle) * Open source: Partially supported (half-filled circle) * Local attestation: Supported (filled circle) * Remote attestation: Supported (filled circle) * API for attestation: Supported (filled circle) * Mutual attestation: Supported (filled circle) * User-mode support: Supported (filled circle) * Industrial TEE: Not supported (empty circle) * **Keystone:** * Integrity: Supported (filled circle) * Freshness: Supported (filled circle) * Encryption: Supported (filled circle) * Unlimited domains: Supported (filled circle) * Open source: Supported (filled circle) * Local attestation: Supported (filled circle) * Remote attestation: Supported (filled circle) * API for attestation: Supported (filled circle) * Mutual attestation: Supported (filled circle) * User-mode support: Supported (filled circle) * Industrial TEE: Not supported (empty circle) * Isolation and attestation granularity: Secure world * System support for isolation: SMC + PMP **RISC-V** * **Sanctum:** * All features except User-mode support are not supported (empty circle). * User-mode support: Supported (filled circle) * Isolation and attestation granularity: Intra-address space * System support for isolation: Tag + MPU * **TIMBER-V:** * All features except User-mode support are not supported (empty circle). * User-mode support: Supported (filled circle) * **LIRA-V:** * All features except User-mode support are not supported (empty circle). * User-mode support: Supported (filled circle) * System support for isolation: PMP ### Key Observations * Client SGX supports most of the listed features, while Scalable SGX has limited support. * TrustZone-A and TrustZone-M primarily support user-mode support. * SEV-ES and Keystone offer comprehensive feature support among the SEV implementations. * RISC-V implementations (Sanctum, TIMBER-V, LIRA-V) mainly support user-mode support. * Industrial TEE is not supported by any of the listed implementations. ### Interpretation The chart provides a comparative overview of feature support across different secure execution environments. It highlights the strengths and weaknesses of each implementation, indicating which features are prioritized in each design. The data suggests that Client SGX, SEV-ES, and Keystone offer more comprehensive security features compared to other implementations listed. The lack of Industrial TEE support across all implementations suggests a potential area for future development. The chart is useful for understanding the trade-offs between different secure execution environments and selecting the most appropriate one for a given application.