A collection of all of the CTF challenges I have written for CTFs hosted by ISSS, CTFs hosted by UTC, and the CTF final(s) for the CS361 class that I TA'd for.
- 119 Problems
- 61 Unique Problems
- 6 Problem Categories
In reverse chronological order by semester
37 Problems
- DH-9000 [crypto]: Diffie-Hellman Brute Force
- Mightier Than The XORd [crypto]: Repeating XOR
- Covert Communication [forensics]: Image Diff
- Documented [forensics]: Hiding Files in
.docx
- Sandwiched [forensics]: File Carving
- Song of Flags [forensics]: Musical Cryptogram
- Unpleasant or Contemptable Person [web]: Exposed
.gitDirectory
- Secret Transmission [crypto]: Affine Cipher
- File Stowaway [forensics]: JavaScript in PDF
- Following Protocol [misc]: Port Numbers
- Key Finding [misc]: SSH Identicon Reverse Engineering (Drunken Bishop)
- Quick Maths [reversing]: Addition and Subtraction Reversing
- Inconspicuous Image [forensics]: GIFAR
- Bookkeeping [misc]: ISBN Check Digit Automation
- Sizzling Bacon [beginner]: Baconian Cipher
- Cipher Gauntlet [beginner]: Binary, Base64, Caesar Cipher
- Run-ELF [beginner]: Run Linux Binary
- Strings [beginner]: Strings on a Binary
- HTML [beginner]: View Source on Website
- Magic Bytes [beginner]: Wrong File Header
- Small P Problems [crypto]: Diffie-Hellman Brute Force
- Wiesner's Quantum Bank [crypto]: Elitzur-Vaidman Bomb Attack on Wiesner's Quantum Money Scheme
- SHIFT [forensics]: Image with Shifted Pixels
- Farmers Only [misc]: Chaffing and Winnowing
- All Your Base Are Belong To Us [crypto]: Base64
- Zeros and Ones [crypto]: Binary
- Bookworm [crypto]: Book Cipher (Chapter, Paragraph, Word, Letter)
- All Greek To Me [crypto]: Caesar Cipher
- DEADBEEF [crypto]: Hexadecimal
- OTP [crypto]: One Time Pad Key Reuse
- Met A Data [forensics]: EXIF Data/Strings
- Magic [forensics]: Wrong File Header
- Redacted [forensics]: Redacted PDF
- Zipped [forensics]: ZIP Cracking
- Uncharted [misc]: Plotting Coordinates on a Map
- Nothing In Between [misc]: Zero Width Characters (as binary)
- Intro to CyberChef [tools]: How to use CyberChef
22 Problems
- The Die Has Been Cast [crypto]: Caesar Cipher
- Substitution [crypto]: Emoji Substitution Cipher
- Redacted [forensics]: Redacted PDF
- Corrupted [forensics]: Wrong File Header
- #1 Opener [crypto]: Pigpen Cipher
- Wumbo [forensics]: PDF CropBox
- Orange Ricky [forensics]: Image Steganography
- Garbage [forensics]: EXIF Data/Strings
- Sharing Secrets [crypto]: Shamir's Secret Sharing
- Vinegar Cipher [crypto]: Vigenere Cipher
- Click Clack Moo [forensics]: JavaScript Keyboard Codes
- Live Más [misc]: Luhn Algorithm
- Dahdit [crypto]: Morse Code
- Pontifex [crypto]: Solitaire Cipher
- Skeleton Wars [forensics]: Hidden Alpha Channel
- Unzipped [forensics]: ZIP Cracking
- Poltergeist [misc]: Whitespace
- ZigZag [crypto]: Railfence Cipher
- Pontifex [crypto]: Solitaire Cipher
- True Hacker [forensics]: EXIF Data/Strings
- SHIFT [forensics]: Image with Shifted Pixels
- This is the flag [misc]: Adding Extra Zero Width Characters
7 Problems
- qwerty [crypto]: Keyboard Shift Cipher
- One True Problem [crypto]: One Time Pad Key Reuse
- Cube Crypto [crypto]: Anshel-Anshel-Goldfeld Encryption using the Rubik's Cube Group
- Curveball [crypto]: Shamir Secret Sharing
- The Legend of Hackerman, Pt. 1 [forensics]: Wrong File Header
- The Legend of Hackerman, Pt. 2 [forensics]: Hiding Files in
.docx - Spectre [forensics]: Spectrogram
14 Problems
- Sbubby [crypto]: Substitution Cipher
- Cat.jpg [forensics]: EXIF Data/Strings
- Delicious Dinner [forensics]: Wrong File Extension
- Donkin Dunnts [forensics]: Image Steganography
- SSH ASCII Art [forensics]: SSH Identicon Reverse Engineering (Drunken Bishop)
- T9 [misc]: T9 Encoding
- Spectrogram [forensics]: Spectrogram
- ZIP Password [forensics]: ZIP Password Cracking
- USB Capture [networking]: Recover Image From USB Packet Capture
- Le Monke [forensics]: Binary Representation Of Letters As A Glyph
- ZIP [forensics]: GIFAR
- OTP [crypto]: One Time Pad Key Reuse
- ASC-Key Art [forensics]: SSH Identicon Reverse Engineering (Drunken Bishop)
- Really Good :B:icture [misc]: Hex Colors to ASCII
26 Problems
- Fence [crypto]: Rail Fence Cipher
- Morse [crypto]: Morse Code Audio
- XOR [crypto]: Repeating XOR
- Audio Steg [forensics]: Spectrogram
- GIFAR [forensics]: GIFAR
- Not The Flag [misc]: Zero Width Characters (as binary)
- OTP [crypto]: One Time Pad Key Reuse
- Sub Cipher [crypto]: Substitution Cipher
- Steg [forensics]: Image Steganography
- Whitespace [forensics]: Whitespace
- Ports [misc]: Port Numbers
- Zero Width [misc]: Adding Extra Zero Width Characters
- Finding Nemo [forensics]: ZIP Password Cracking & Zero Width Fingerprinting
- You've Got A Flag In Me [forensics]: GIFAR
- Candide [crypto]: Book Cipher (Chapter, Paragraph, Word, Letter)
- Whitespace [forensics]: Whitespace
- Morse [crypto]: Morse Code (that looks like binary)
- Steg [forensics]: Image Steganography (hidden in red channel of pixel 0, green channel of pixel 1, blue channel of pixel 2, etc.)
- Deseret [misc]: Deseret Alphabet
- Rubikstega [crypto]: Rubik's Cube Based Steganography (it was broken this time, revamped for UTCTF)
- Peter Pan [forensics]: Semicolon/Greek Question Mark Binary
- Scrambled [crypto]: Rubik's Cube Based Steganography
- Tale of Two Cities [crypto]: Shift Cipher with OEIS Sequence
- Low Sodium Bagel [forensics]: Image Steganography
- RIP [forensics]: ZIP Password Cracking
- DragonScim 2 [recon]: Reconaissance
13 Problems
- Acting Shifty [crypto]: Vigenere Cipher
- Keep It Zipped [forensics]: ZIP Password Cracking
- MTV Cribs [crypto]: One Time Pad (OTP) Key Reuse
- Get Wavy [forensics]: Spectrogram
- Easy RSA [crypto]: RSA
- Stwing [forensics]: EXIF Data/Strings
- Whitespace [forensics]: Whitespace
- Substitution [crypto]: Emoji Substitution Cipher
- GIFAR [forensics]: GIFAR
- Salad [crypto]: Caesar Cipher
- Artist [forensics]: Wrong File Header
- I Love It [forensics]: Morse Code Audio
- LFSR [misc]: Linear Feedback Shift Register