M.I.T. DEPARTMENT OF EECS

Assignment 7: April 1 through April 8

For Lecture, Wednesday, April 1 (L 15: Authorization)

In preparation for this lecture, read the second section (pp 6-16 to 6-29) of "The protection of information in computer systems" by Saltzer and Schroeder (#25).

For Recitation, Thursday, April 2 (R 15: More security)

To prepare for recitation read Appendix 6.A from "The protection of information in computer systems" by Saltzer and Schroeder (pp 6-34 to 6-55).

For Lecture, Monday, April 6 (L 16: Certification)

The last lecture on security. No specific reading assignment for today, but you might want to get going on the reading and assignment for tomorrow.

For Recitation, Tuesday, April 7 (R 16: Safe-Tcl)

Each year we construct a handout on "Recent Issues Regarding Security and Privacy". This year's handout will be distributed in recitation on March 31. It contains three papers; the first is also available online.

• J. Ousterhout, J. Levy, B.Welch. The Safe-Tcl Security Model, Draft, March 26, 1997.
• L. Gong. Java Security: Present and Near Future. IEEE Micro, 17(3):14-19, May/June 1997
• L. Gong, R. Schemers. Implementing Protection Domains in the Java Development Kit 1.2. In Proceedings of the Internet Society Symposium on Network and Distributed Security, San Diego, CA, March 1998

Answer the question below for this week's assignment:

"The Safe-Tcl Security Model" by Ousterhout, Levy, and Welch explains how Safe-Tcl allows different security policies for different applets rather then adopting a single security policy for all applets. Discuss the main benefit and the main risk of Safe-Tcl's approach.

See the course secretary, Neena Lyall, in NE43-523 if you didn't get one.

For Lecture, Wednesday, April 8 (L 17: Fault Tolerance)

This lecture begins a new topic of fault-tolerant computing systems. In preparation, read "Chocolate" by Plauger (#27) and "Engineering: history and failure" by Petroski (#26). These two papers are very short, but provide you with some good insights.

System aphorism of the week

The unavoidable price of reliability is simplicity. (C.A.R. Hoare)