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content/CSE4303/CSE4303_L12.md

@@ -0,0 +1,24 @@
+# CSE4303 Introduction to Computer Security (Lecture 12)
+
+## Asymmetric Encryption
+
+### Motivation
+
+#### Symmetric key exchange: TTPs
+
+Idea: Trusted Third Party (TTP) is always-available key manager
+
+- Assume secure channel exists between every user and TTP
+  - KA = shared key between user A and TTP
+- Generates/distributes keys to user pairs on demand
+  - KAB = shared key between user A and user B
+
+Symmetric-key encryption: challenges
+
+1. Key storage: one per user pair, $O(n^2)$ total for $n$ users
+2. Key exchange: how to do it over non-secure channel?
+
+### Key Exchange
+
+[Diffie-Hellman](https://notenextra.trance-0.com/CSE442T/CSE442T_L16/#diffie-helmann-key-exchange)
+

content/CSE4303/_meta.js

@@ -15,4 +15,5 @@ export default {
     CSE4303_L9: "Introduction to Computer Security (Lecture 9)",
     CSE4303_L10: "Introduction to Computer Security (Lecture 10)",
     CSE4303_L11: "Introduction to Computer Security (Lecture 11)",
+    CSE4303_L12: "Introduction to Computer Security (Lecture 12)",
 }