CS 116: Introduction to Security

Tufts University Department of Computer Science, Fall 2026

Course Description

A holistic and broad perspective on cyber security. Attacking and defending networks, cryptography, vulnerabilities, reverse engineering, web security, static and dynamic analysis, malware, forensics. Principles illustrated through hands-on labs and projects, including Capture The Flag (CTF) games.

Sections

1. In-person, undergrads and grads: Tuesdays, 4:30 - 5:45 PM EST in Barnum Hall 104; Thursdays on Twitch, 4:30 - 5:45 PM EST
2. Online Master's in Computer Science: live sessions on Wednesdays, 5:30 - 7:00 PM EST (via Zoom)

Instructor

• Ming Chow, ming.chow@tufts.edu
• In-Person Office Hours: Tuesdays, 3:00 - 4:15 PM EST in in Joyce Cummings Center (JCC), Computer Science Main Office

Prerequisites

• CS 15 or Data Structures equivalent course. Recommended (not required) that you have taken CS 30 or 40. Please disregard prerequisite that CS 40 is required as listed in the University's bulletin as they are incorrect!

Hardware and Software for This Class (on your personal computer)

Absolute Requirements

• A modern web browser (e.g., Firefox, Google Chrome, Chromium, Safari, Microsoft Edge)
• A command line interface to run Unix/Linux commands (e.g., macOS, Windows with Linux Subsystem, a Linux-based virtual machine, a Docker container)

List of Security Tools That Will Be Used in Course

The following is a list of security tools that will be used in the course. All of these tools are platform-independent.

• Wireshark
• Nmap
• Netcat
• Python
• Scapy
• John the Ripper
• Burp Suite
• apktool and Java as apktool requires Java

Assessment

• Labs (65%)
• Quizzes (30%)
• Outside-the-Classroom Engagement (5%)

How Quizzes Work Starting Fall 2026

For the in-person section of the course, in-person quiz returns. Since spring 2020, quizzes were done online, electronically, one chance, open book, open everything, no time limit. You can understand why that's not a great idea any more. An important point of this course is basic literacy of key concepts without the help of AI.

On Tuesdays starting week of Tuesday, September 15th, there will be a quiz at the end of the class on the previous week's topic. There will be 3 questions per quiz. Each question will be one of the following: multiple choice, fill-in-the-blanks, True/False, drawing, find the mistake. There is a 15 minute time limit for everyone. Quiz is closed book.

Grading:

• Check Plus: 3 / 3
• Check: 2 / 3
• Check Minus: [0 - 1] / 3
• No Show: Zero

At the end of the semester, the lowest 3 quizzes will be dropped automatically (e.g., in case of illness, job interview, emergency, hookie, no show --yes, no shows can be dropped). No quiz makeup. Answers to quiz will be posted within 24 hours.

For students in the online Wednesday section, two quizzes will be given in the semester as in semesters since fall 2020.

What is Outside-the-Classroom Engagement?

In order to be a successful in the Cybersecurity field --or any field for that matter, you need to do most learning on your own outside of the classroom. Just doing the classroom work is never good enough. Outside-the-Classroom engagement are semester-long activities for you to connect the material of this class to the real world. Each activity will be marked either complete or incomplete. There will be five activities this semester, you need to do four of the five, due Tuesday, December 1st at 11:59 PM Pacific Time:

1. Provide a real world example of a Distributed Denial of Service (DDoS) attack since the start of this semester. Providing URL to an article is sufficient.
2. Provide a real world example of a malware campaign since the start of this semester. Providing URL to an article is sufficient.
3. Provide a real world example of a vulnerability since the start of this semester. Vulnerabilities must have associated CVEs. Providing URL to an article is sufficient.
4. Provide a real world example of a data breach since the start of this semester. Providing URL to an article is sufficient.
5. Choose one: (1) provide an example of an LLM providing incorrect response, or (2) show an example of prompt injection. You can use any LLM that you want (e.g., ChatGPT, Gemini, Claude). Show screenshot or share chat.

What Inspired the Outside-the-Classroom Engagement?

In fall 2025, Tristan Tew, a student in the course, shared an article that got me very angry (no, not at Tristan). The article was very relevant to the current topic of the week and to the course as a whole. It occurred to me that I wish more students shared content relevant to the course.

Course Infrastructure

• Lab submissions: Canvas (Tufts UTLN required)
• Quizzes: Canvas (Tufts UTLN required)
• Announcements: Piazza
• Discussions: Piazza

Syllabus

Important note: always follow Canvas for due date on labs!

House Rules

1. You lose two full letter grade if you ask if there is a final exam (during the final exam period) in this course.
2. There is no class on the week of Thanksgiving (week of November 23rd). Book your travels now.
3. For each lab, you have unlimited submissions --prior to marked due date and time on Canvas. If I grade your lab before due date and time, and you make mistakes, you can resubmit for regrading. I call this "Advanced Grading."
4. There is a Tufts CS Discord. If you DM me on an academic issue (anything pertaining to grades or coursework), I will block you. This Discord is for anything other than academics.
5. If you want your resume reviewed, just email it me and be sure to attach a PDF copy.
6. Don't call me "Professor", just address me by my first name. Thank you.

Frequently Asked Questions

Q: Is there a textbook for this course?

A: No

Q: Are there teaching assistants (TAs) for this course?

A: No

Q: What is the workload of this course?

A: Here is a list of all the labs with expected length and difficulty:

• Lab 1: Working with the Command Line, Long (3+ hours) --you can put in as much time as you want on this lab
• Lab 2: Packet Sleuth, Medium (1 - 3 hours)
• Lab 3: Scanning and Reconnaissance, Your mileage may vary on this lab, could be 30 minutes, could be 2 hours or more. NOTE: This lab cannot be made publicly available because an actual target is used.
• Lab 4: Python and the Incident Alarm, Long (3+ hours) to Impossible
• Lab 5: The Password Cracking Contest, If you crack all the password hashes (read: good luck with that), you will receive an automatic "A" in the course
• Lab 6: The XSS Game, Medium to Long.
• Lab 7: Gain Access to Website, Very short. NOTE: This lab cannot be made publicly available because an actual target is used.
• Lab 8: The CTF Game, One week --team based. NOTE: This lab cannot be made publicly available because an actual target is used.
• Lab 9: Technical Risk Analysis, Short to Medium.
• Lab 10: Android Malware Analysis, Short to Medium.

Q: Does this course count towards the M.S. in Cybersecurity and Public Policy?

A: Yes

Q: Does this course count towards the M.S. in Software Systems Development?

A: Yes. In fact, this is one of the four required courses for the M.S.

Q: Did you remove information on using Kali virtual machine for this class? If so, why?

A: Yes. After all these years, it was more trouble than it was worth. Further reasons:

1. Accessibility. For students who are visually impaired, using a virtual machine can be very difficult.
2. Not all students have a capable laptop. Sometimes due to financial reasons, some students use Chromebooks. The tools required for this course can be installed natively on macOS, Windows, and Linux.
3. Performance. Sometimes, using a VM can be very slow. A VM also do not use native drivers (e.g., for networking).
4. Hard disk space requirement: at least 10 GB necessary.
5. Apple M1 Macs cannot run most Intel x86 virtual machines.

Q: Is Piazza used in this course?

Yes, quite a lot

Q: Why is there a course website and a course Canvas? If you say "it is a nuisance for students to use multiple websites and services for one course", what gives?

This course website serves a few critical purposes. Years ago, I made a decision to make all the readings, slide decks, and most of the labs publicly available. The reasons: (1) to show that Tufts is serious and is working on Cyber Security matters, (2) to provide learning material to the public on Cyber Security as the Cyber Security education problem is very dire, (3) for recordkeeping on what is taught and not taught in this Security class --this comes up often when we speak to industry and organizations who want to work with Tufts on Cyber Security-related matters. The Canvas site for this course isn't made publicly available. Even if Canvas site was made publicly available, content is behind a walled garden, and (4) for redundancy if Canvas goes down.

Q: I have not taken a course on Networks (CS 112), Operating Systems (CS 111), or Computer Architecture (CS 40) yet. Is that a problem?

No. Cyber Security is a very broad field and it is impossible for anyone, even professionals, to know everything. What is important for you is to start thinking about Security.

Q: Will videos be recorded in case I miss class?

If you miss the in-person Tuesday classes due to illness or personal matters, you can always watch the recorded Wednesday sessions for online Master's students (Wednesday sessions are always recorded). Tuesday and Wednesday sessions are practically identical. Thursdays are on Twitch which are recorded and also exported to YouTube.

Q: If I am taking this course for professional purpose, can I have a tuition reimbursement letter or certificate?

A: Absolutely! It's a nice tuition reimbursement letter, hand signed!

If you the human have read this far, send me an email (ming.chow AT tufts DOT edu) with the subject "Health, History, and Horses" to earn a reward.

Course Policies

Labs

• With the exception of the CTF writeup, all labs for a given topic, are due on a Sunday at 11:59 PM Pacific Time.
• With the exception of password cracking lab, the CTF game, quizzes, and outside-the-classroom engagement activities, you are granted an automatic extension of 24 hours at no cost (i.e., grace period). A lab or quiz submitted after the grace period will not be accepted.
• No extension tokens.

Accessibility Statement

Tufts is committed to providing equal access and support to all qualified students through the provision of reasonable accommodations so that each student may fully participate in the Tufts experience. If you have a disability that requires accommodations, please contact the StAAR Center (formerly SAS) staarcenter@tufts.edu or 617-627-4539 to make an appointment to determine appropriate accommodations. Please be aware that accommodations cannot be enacted retroactively, making timeliness a critical aspect for their provision. You can learn more about the StAAR Center at https://students.tufts.edu/student-accessibility-services.

Expectations and Structure of This Course

This course will be a fun one for sure. A few notes on the expectations and structure of this course:

1. You are responsible for your own learning.

A very important point: if you want everything gone over in lecture or in notes, then this is not the course for you. More importantly, that's not how things work in real life.

2. You will learn by doing.

Each week, there will be at most three labs to hone your skills and to aim at the crux of the matter for the week. Here's an analogy: you don't learn how to cook simply by just reading cookbooks and watching YouTube videos. You learn by making, using your hands, and making mistakes.

3. You will learn by asking questions.

It is your responsibility to ask questions early and to ask for help...

4. ...and I expect discussions online to be very active and civil.

Share thoughts and respond to other people's questions. I will be online constantly. It is no secret that I respond very quickly unless I need to be away.

5. This course has a venerable history. Expectations are to the skies for each and every one of you.