1. Agenda Midterm Notes Taco Bell Case Chapter 5 Computer Security

2. Taco Bell Case - Questions Why is this an example of proper scoping of functions? Would you have used “evolution” or “revolution” to update the infrastructure? What maintains control given the decentralized decision process?

3. Chapter 5 Highlights Infrastructure effects the ability to differentiate Metcalfs’s Law Over focus on “realtime” Complex systems increase process failure probability: redundancy? Net Services as “utility”

4. Computer Security Basics Identification/Authentication/Access Audit Directory Services: LDAP

5. Network Security Basics Single sign-on Trusted machines Firewalls TCP/IP Secure Ports/sockets

6. Single Sign-on Security Server Application Server User/Client 1 2 3 4 5 1: Login to SS 2: Get token 3: login to AS (pass token) 4: AS chk token 5: SS ok’s token

7. Router Firewall Firewall Router Accept List / Exclude list From: 12.3.4.68 To: 136.167.2.34 Type: Telnet From: 136.167.2.34 To: 12.3.4.68 Type: Telnet

8. Routed Network Design Router 136.167.2 I-net router 136.167 Client LAN Router 136.167.10 Campus Backbone

9. Encryption Asymmetric keys Public / private keys Digital Certificates SSL / HTTPS Secured Transactions

10. PKI Process PKI Service PKI Client Send Public key Return encoded symmetric key Send login req using sym key Conduct work Time’s up! Send new sym key info

11. VPN / Remote Access Goals VPN Mechanism VPN Problems Proxy Server