CT: Factoring High-Level Authorizations into Kernel-Level Configurations

授权模型限制用户和程序(进程)可以在计算机系统上做什么，从而保护计算机系统及其数据不受恶意用户和程序的影响。在操作系统中实现的授权模型使用访问矩阵作为其基本抽象。访问矩阵使得授权模型能够有效地实现，这是至关重要的，因为它的开销是由在计算机系统中执行的每个程序引起的。随着接入矩阵的增强以在当今的高威胁环境中提供足够的保护，导致了更大的复杂性；这种复杂性导致用户避免或滥用这种保护。另一方面，当今最流行的系统缺乏更强有力的保护，使得它们容易受到越来越多的攻击。该项目正在构建一个两级系统，较高级别的授权面向指定授权策略的人的需求，而较低级别的授权针对高效执行而定制。因此，较低级别可以在操作系统内核中实现。高级授权将被自动转换(“分解”)为操作系统级授权。这些高级别和低级别授权是独一无二的，因为它们是共同开发的，因此共享基本概念，从而使自动保理变得实用。

Authorization models limit what users and programs (processes) can do on a computer system, thereby protecting computer systems and their data from malicious users and programs. Authorization models implemented in the operating system employ the access matrix as their fundamental abstraction.The access matrix enables efficient implementation of an authorization model, which is critically important since its overheads are incurred by every program executing in the computer system. As the access matrix is enhanced to provide adequate protections in today's high threat environment, greater complexity results; this complexity leads to users avoiding or misusing such protections. On the other hand, the lack of stronger protections in today's most popular systems renders them vulnerable to increased attacks.This project is building a two-level system, with the higher level authorizations oriented towards the needs of those who specify authorization policies and the lower level tailored for efficient execution. Thus the lower level can be implemented in the operating system kernel. The high-level authorization will be automatically translated ("factored") into the operating system level authorizations. These high and low level authorizations are unique in that they were co-developed, and thus share basic concepts, which make this automatic factoring practical.