Update README.md

Author: jess-lemur

README.md

@@ -42,7 +42,7 @@ Students by the end of the course will be able to ...
 |  8 |  Tue, Sept 15              | [Abstract Classes & Static/Class Methods] |
 |  9 |  Thu, Sept 17              | [Multiple Inheritance & Mix-ins] | Quiz 2
 | 10 |  Tue, Sept 22              | [How Computers Work] |
-| 11 |  Thu, Sept 24              | Special Topics | [OOP Design Challenge]
+| 11 |  Thu, Sept 24              | [Computer Security] | [OOP Design Challenge]
 | 12 |  Tue, Sept 29              | Special Topics  |
 | 13 |  Thu, Oct 1                |Lab Day |
 | 14 |  Tue, Oct 6                | OOP Design Challenge Presentations |
@@ -76,6 +76,8 @@ Students by the end of the course will be able to ...
 
 [OOP Design Challenge]: Lessons/oop_design_challenge.md
 
+[Computer Security]: https://docs.google.com/presentation/d/1b0JzyKVXwFR3BYNUiotubD86JzkDUqwiNIklq0yVzP8/edit#slide=id.g9b3e8fe2e2_0_63
+
 ## Class Assignments
 
 We will be using Gradescope, which allows us to provide fast and accurate feedback on your work. All assigned work will be submitted through Gradescope, and assignment and exam grades will be returned through Gradescope.