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CS161 Spring 2026
Instructors: Henry Corrigan-Gibbs, Raluca Ada Popa / Lecture: MWF, 3:00–4:00 PM, Wheeler 150 [Zoom, Playlist]
Announcements
Welcome to CS 161!
Hi everyone and welcome to CS 161 Spring 2026!
First Lecture
Our first lecture will be on Wednesday, January 21 in Wheeler 150.
- All lectures this semester will be recorded and posted on the course website
- All lectures will be live-streamed over Zoom, but we will offer extra credit for in-person attendance after week 3.
Course Communication
We will be using Ed and the course website as the main forms of communication for this class.
Office Hours and Discussions
See the course calendar for the office hours and discussion schedule.
Exams
The midterm is on Thursday, March 12 from 7–9PM PT.
The final exam is on Wednesday, May 13 from 7–10PM PT.
Questions
If you have any questions or comments, please first check out the course policies page and the Spring 2026 FAQs page. If your question is not answered after reading those two pages, feel free to post a follow up on Ed.
Course Calendar
| Wk. | Date | Lecture | Discussion | HW | Project |
|---|---|---|---|---|---|
| 1 |
Wed Jan 21 | 1. Introduction and Security Principles Slides / Recording / Ch. 1 |
0. 61C Review Discussion: Worksheet / Solutions / Video / Slides |
HW1
(due Fri Jan 30) |
Project 1 Checkpoint
(due Fri Feb 06) |
|
Fri Jan 23 | 2. x86 Assembly and Call Stack Slides / Recording / Ch. 2 / x86/GDB Cheat Sheet |
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| 2 |
Mon Jan 26 | 3. Memory Safety Vulnerabilities Slides / Recording / Ch. 3 |
1. Security Principles and x86 Discussion: Worksheet / Solutions / Video / Slides Exam Prep: Worksheet / Solutions / Video / Slides Bridge: Slides |
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Wed Jan 28 | 4. Memory Safety Vulnerabilities II Slides / Video / Recording |
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Fri Jan 30 | 5. Mitigating Memory Safety Vulnerabilities Slides / Recording / Ch. 4 |
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| 3 |
Mon Feb 02 | 6. Intro to Cryptography Slides / Recording / Ch. 5 |
2. Memory Safety Discussion: Worksheet / Solutions / Video / Slides Exam Prep: Worksheet / Solutions / Video / Slides Bridge: Slides |
HW2
(due Fri Feb 13) |
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Wed Feb 04 | 7. Pseudorandom Functions and Block Ciphers Slides / Recording / Ch. 6 / Ch. 9 |
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Fri Feb 06 | 8. Block Cipher Modes of Operation Slides / Recording / Ch. 6 |
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| 4 |
Mon Feb 09 | 9. Collision-resistant Hash Functions Slides / Ch. 7 |
3. Memory Safety Mitigations Discussion: Worksheet / Slides Exam Prep: Worksheet / Slides Bridge: Slides |
Project 1
(due Fri Feb 13) |
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Wed Feb 11 | 10. Message Authentication Codes Slides / Ch. 8 |
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Fri Feb 13 | 11. Authenticated Encryption Slides |
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| 5 |
Mon Feb 16 | No Lecture (Presidents’ Day) |
4. Symmetric Cryptography Discussion: Slides Exam Prep: Slides Bridge: Slides |
HW3
(due Fri Feb 27) |
Project 2 Spec Quiz
(due Fri Feb 20) |
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Wed Feb 18 | 12. Key Exchange and Public-Key Encryption Slides / Ch. 10 |
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Fri Feb 20 | 13. Discrete log and Diffie-Hellman Slides / Ch. 11 |
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| 6 |
Mon Feb 23 | 14. Digital Signatures Slides / Ch. 12 |
5. Integrity and Authenticity Discussion: Slides Exam Prep: Slides Bridge: Slides |
Project 2 Design Checkpoint
(due Fri Feb 27) |
|
|
Wed Feb 25 | 15. Randomness and Crypto Implementation Bugs | ||||
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Fri Feb 27 | 16. Introduction to Web Slides / Ch. 18 / Ch. 19 / Ch. 20 |
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| 7 |
Mon Mar 02 | 17. Cookies and CSRF Slides / Ch. 20 / Ch. 21 |
6. Asymmetric Cryptography Discussion: Slides Exam Prep: Slides Bridge: Slides |
HW4
(due Fri Mar 06) |
Project 2 Testing Checkpoint
(due Fri Mar 20) |
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Wed Mar 04 | |||||
| 18. Certificates, Passwords, and Case Studies Slides / Ch. 13 / Ch. 14 |
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Fri Mar 06 | |||||
| 8 |
Mon Mar 09 | 19. XSS Slides / Ch. 22 |
7. Cookies and CSRF Discussion: Slides Exam Prep: Slides Bridge: Slides |
HW5
(due Fri Mar 20) |
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Wed Mar 11 | |||||
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Thu Mar 12 | Midterm (7-9PM) |
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Fri Mar 13 | 20. UI Attacks Slides / 23 |
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| 9 |
Mon Mar 16 | 21. SQL Injection and CAPTCHAs Slides / Ch. 17 / Ch. 24 |
8. SQL Injection and XSS Discussion: Slides Exam Prep: Slides Bridge: Slides |
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Wed Mar 18 | |||||
| 22. Intro to Networking Slides / Ch. 25 |
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Fri Mar 20 | |||||
| 10 |
Mon Mar 23 | No Lecture (Spring Recess) |
No Discussion (Spring Recess) | HW6
(due Fri Apr 10) |
Project 2
(due Fri Mar 27) |
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Wed Mar 25 | |||||
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Fri Mar 27 | |||||
| 11 |
Mon Mar 30 | 23. Low-Level Network Attacks Slides / Ch. 26 / Ch. 27 / Ch. 28 / Ch. 29 |
9. ARP, DHCP, WPA Discussion: Slides Exam Prep: Slides Bridge: Slides |
Project 3
(due Fri Apr 10) |
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Wed Apr 01 | |||||
| 24. BGP and Transport Layer (TCP and UDP) Slides / Ch. 30 |
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Fri Apr 03 | |||||
| 12 |
Mon Apr 06 | 25. TLS Slides / Ch. 31 |
10. TCP and TLS Discussion: Slides Exam Prep: Slides Bridge: Slides |
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Wed Apr 08 | |||||
| 26. DNS Slides / Ch. 32 |
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Fri Apr 10 | |||||
| 13 |
Mon Apr 13 | 27. DNSSEC Slides / Ch. 33 |
11. DNS Discussion: Slides Exam Prep: Slides Bridge: Slides |
HW7
(due Fri Apr 24) |
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Wed Apr 15 | 28. Denial of Service and Firewalls Slides / Ch. 34 / Ch. 35 |
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Fri Apr 17 | 29. Intrusion Detection Slides / Ch. 36 |
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| 14 |
Mon Apr 20 | 30. TBD | 12. Intrusion Detection Discussion: Slides Exam Prep: Slides Bridge: Slides |
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Wed Apr 22 | 31. AI Security | ||||
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Fri Apr 24 | |||||
| 15 |
Mon Apr 27 | 32. AI Security | 13. AI Security Discussion: Slides Exam Prep: Slides Bridge: Slides |
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Wed Apr 29 | |||||
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Fri May 01 | 33. iPhone Security | ||||
| 16 |
Mon May 04 | No Lecture (RRR Week) |
Topical Review Sessions (RRR Week) | ||
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Wed May 06 | |||||
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Fri May 08 | |||||
| 17 |
Wed May 13 | Final Exam (7–10PM) |
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