《Operating System Concepts》學習第 71 天，p808-p820 總結，總計 13 頁。

一、技術總結

1.design principles of windows

(1)security

滿足 C2 級別，基于 Discretionary Access Control(DAC)，attribute-based access control (ABAC)， claim-based access control (CABC)等。

二、英語總結(生詞：2)

1.bounty

(1)bounty: bonus("good") + -ty

c. money paid as a reward(獎金，賞金)。

(2)示例

Additionally, bug bounty participation programs allow external researchers and security professionals to identify, and submit, previously unknown security issues in Windows(《Operating System Concepts》第 826 頁)。

2.discretionary

(1)discern: dis-("apart, away") + cernere("distinguish, separate, sift",參考 *krei-"to seive(過濾，篩)", hence "distinguish")

vt. discern literally means to separate by distinguishing. to recognize sth that is not clear(辨別出)。

(2)discrete: dis-("apart, away") + cernere("distinguish, separate, sift",參考 *krei-"to seive(過濾，篩)", hence "distinguish")

adj. individually separate and distinct(獨立的，各自的).

(3)discretion

u. the quality of behaving in such a way as to avoid causing offence(慎重)。

(4)discretionary: discretion + -ary

adj. available for use at the discretion of the user(可自行決定的，自主的)。

(5)示例

Windows traditionally based security on discretionary access controls. System objects, including files, registry keys, and kernel synchronization objects, are protected by access-control lists (ACLs) (see Section 13.4.2).(《Operating System Concepts》第 826 頁)。

上面這句話的意思是：Windows 傳統上將安全性建立在自主訪問控制（Discretionary Access Control, DAC）基礎上。系統對象（包括文件、注冊表鍵和內核同步對象）都通過訪問控制列表（ACLs）進行保護（參見第13.4.2節）。

關于英語的注解同步更新匯總到 https://github.com/codists/English-In-CS-Books 倉庫。

三、其它

第 21 章(Windows 10)簡評：分別從 History, Design Principles, System Components 等方面介紹 windows 系統，總體而言介紹很詳細，介于實際開發中與 Windows 相關的內容并不多，所以選擇快速過一遍即可。

完結，撒花，明天出讀后感。

四、參考資料

1. 編程

(1) Abraham Silberschatz，Peter Baer Galvin，Greg Gagne《Operating System Concepts》：https://book.douban.com/subject/30272539/

2. 英語

(1) Etymology Dictionary：https://www.etymonline.com

(2) Cambridge Dictionary：https://dictionary.cambridge.org

歡迎搜索及關注：編程人(a_codists)