![suomeksi](http://www.cs.Helsinki.FI/gif/f-fi.gif)
Operating Systems II, Spring 2005, HW 6
This will be covered in practise session during the week 18 (3-4.5.2005).
Please notice that there in no practice session on Ascencion Day 5.5.2005. Students in Thursday practice session should visit Tuesday or Wednesday groups.
- Password search
- Problem 16.1 from text book [Stal 05, p. 722] (problem 15.1 [Stal 01, p. 690])
- Problem 16.4 from text book [Stal 05] (problem 15.4 [Stal 01])
- What can you deduce from this?
- Password salt
- Problem 16.7 from text book [Stal 05] (problem 15.7 [Stal 01])
- Problem 16.8 from text book [Stal 05] (problem 15.8 [Stal 01])
- Is there real practical advantage with salt?
- Multilevel security
- Problem 16.10 from text book [Stal 05] (problem 15.9 [Stal 01])
- Problem 16.11 from text book [Stal 05] (problem 15.10 [Stal 01])
- Why would MAC be safer than DAC (discretionary access control)?
- "No read up" and "no write down" MAC policy protects data access,
but not data integrity. Why? Give an example.
- User A owns file ASecret, which only A can read or write. A has program AGame, which can use file ASecret during execution? A lets user B play the game AGame and during playing B can read or write file ASecret.
- How would one implement the scheme described above in UNIX?
- How would one implement the scheme described above in W2000?
- How does the situation change, if B should be able read ASecret during
playing, but not to write into it?
Give new answers to parts a and b.
- Clustering and Grid-computing (as defined at the end of Lecture 12)
- Give an example application that would be suitable for Beowulf Linux Cluster'iin, but not for Windows 2000 Cluster Server. Why?
- Give an example application that would be suitable for clusters but not for grids. Why?
- Which synchronization primitives are suitable for SMP, but not for clusters? Why?
- Which synchronization primitives are suitable for clusters, but
not for grids? Why?
Teemu Kerola 21.04.2005 16:21