- Character Encoding (easy)
- Base 2 2 the 6 (easy)
- Morse Code (easy)
- Vigenere Cipher (easy)
- BruXOR (easy)
- Reverse Polarity (easy)
- Hextroadinary (easy)
- HyperStream Test #2 (easy)
- Modern Gaius Julius Cesar (easy)
- Suspecious message (easy)
- Tone dialing (easy)
- The Safest Encryption (medium)
- RSA Beginner (medium)
- Substitution Cipher (medium)
- RSA Noob (medium)
- 5x5 Crypto (medium)
- ALEXCTF CR2: Many time secrets (medium)
- Zippy.zip (medium)
- CoppeRSA Lattice (hard)
- Polycrypto (hard)
- Image Editing (hard)
- A secure LCG? (hard)
- So many 64s (hard)
- Symbolic Decimals (hard)
- The Simpsons (hard)
- Encryption Master (hard)
- RSA Twins! (hard)
- We want Nudes instead of Nukes (hard)
- Linear-feedback. Shift. Register. (hard)
- Common Secret (hard)
- XOR Is Friend Not Food (hard)
- Defying Hell (hard)
- Skynet Is (Almost) Taking Over (hard)
- The Most Secured Crypto-Channel (hard)