Answer the following questions. For questions asking for short answers, there may not necessarily be a "right" answer, although some answers may be more compelling and/or much easier to justify. But I am interested in your explanation as much as the answer itself. Also, do not use shorthand: write your answers using complete sentences.
When grading homeworks, we will grade one question in detail and assign full credit for answers to the others.
Support your answers with a bit of explanation, such as a concise summary explanation in your own words (a quote of a phrase or sentence from the papers is fine as well). For instance, two possible answers to part (a) for Hydra are:
In other words, we're looking for more than just "local name space" — but at the same time your answers don't have to be lengthy discussions. The balance in the example above is fine.
A protection domain in Hydra is the "local name space" (LNS). An LNS represents the current set of objects and rights to which a process has access, and those objects and rights change when a process moves from one LNS to another.
A protection domain in Hydra is the "local name space" (LNS): "At any instant, the execution environment (domain) of a program is defined by an LNS object associated with it...the rights lists in each capability define the permissible access rights of this program at this instant." (Hydra p. 341).
Given that the operating systems we use today on our desktops, laptops, servers, and handheld devices are all essentially forms of Unix, what do your rankings above say about the properties we have optimized for in the operatings systems we use?