标题： 通过可组合隔离的统一低级抽象重新思考保密云 显示英文标题

标题： Rethinking the confidential cloud through a unified low-level abstraction for composable isolation

摘要： 保护敏感的云工作负载需要将机密虚拟机（CVM）与嵌套的可信执行环境或沙箱组合起来。 不幸的是，每个新的隔离边界都会添加临时的访问控制机制、硬件扩展和可信软件。 这种日益复杂的状况增加了可信计算基（TCVM），使端到端的认证变得复杂，并导致平台和云服务提供商（CSPs）之间的碎片化。 我们引入了一种统一的隔离模型，将可执行、可组合和可认证的隔离委托给一个可信的安全监控器： Tyche。 Tyche提供了一个API，通过其核心抽象——信任域（TDs），实现资源的分区、共享、认证和回收。 为了提供细粒度的隔离，TDs可以递归地创建和管理子-TDs。 Tyche在认证中捕获这些关系，使云租户能够推理端到端的安全性。 TDs是构建可组合的可信执行环境、沙箱和CVM的基本构件。 Tyche运行在通用x86_64架构上，无需硬件安全扩展，并且可以与现有软件保持向后兼容性。 我们提供了一个SDK，以最小的开销将未修改的工作负载作为沙箱、可信执行环境和CVM运行和组合，与原生Linux执行相比。 Tyche支持复杂的云场景，例如具有相互不信任的用户、模型所有者和CSP的机密推理。 一个额外的RISC-V原型展示了Tyche在不同平台间的可移植性。 显示英文摘要

摘要： Securing sensitive cloud workloads requires composing confidential virtual machines (CVMs) with nested enclaves or sandboxes. Unfortunately, each new isolation boundary adds ad-hoc access control mechanisms, hardware extensions, and trusted software. This escalating complexity bloats the TCB, complicates end-to-end attestation, and leads to fragmentation across platforms and cloud service providers (CSPs). We introduce a unified isolation model that delegates enforceable, composable, and attestable isolation to a single trusted security monitor: Tyche. Tyche provides an API for partitioning, sharing, attesting, and reclaiming resources through its core abstraction, trust domains (TDs). To provide fine-grain isolation, TDs can recursively create and manage sub-TDs. Tyche captures these relationships in attestations, allowing cloud tenants to reason about end-to-end security. TDs serve as the building blocks for constructing composable enclaves, sandboxes, and CVMs. Tyche runs on commodity x86_64 without hardware security extensions and can maintain backward compatibility with existing software. We provide an SDK to run and compose unmodified workloads as sandboxes, enclaves, and CVMs with minimal overhead compared to native Linux execution. Tyche supports complex cloud scenarios, such as confidential inference with mutually distrustful users, model owners, and CSPs. An additional RISC-V prototype demonstrates Tyche's portability across platforms.