jan26 - CS 426 class...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
CS 426 class Jan 26, 2012 www.cs.purdue.edu/homes/ssw/cs426/{index.html,syll.pdf,outline} (General purpose) Operating System security OS is pgm, so Chapter 3 applies: virus, worm, trapdoor, covert, SE Read Chapter 4 Here we consider security problems specific to OS (no networks yet). History - single user, executive helps; multiuser: monitors What does a (multiuser) OS protect? memory sharable I/O - nonremovable disks serially reusable I/O - printers, tape, removable disks sharable pgms and data OS protects these via kinds of separation: physical (2 printers or cores) temporal (different times) logical (users see no other program) cryptographic (encipher data) Levels of protection (in order easy to hard): none - okay with physical or temporal separation isolation - OS confines each process so that users see no other program share all or share nothing - owner chooses share via access limitation - OS checks each potential access; if <user, object> allowed, okay; OS keeps list share by capabilities - dynamic sharing of rights by owner RWX
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 02/23/2012 for the course CS 426 taught by Professor Staff during the Spring '08 term at Purdue.

Page1 / 2

jan26 - CS 426 class...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online